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Background: Osteochondral defects of the medial femoral condyle combined with varus malalignment in young and active patients are a debilitating condition, which can result in early osteoarthritis. Osteochondral autologous transfer (OAT) combined with valgus high tibial osteotomy (HTO) might therefore be a comprehensive solution to maintain long-term knee function., Purpose/hypothesis: The purpose of this study was to report clinical results and survivorship after combined OAT and valgus HTO for symptomatic osteochondral defects of the medial femoral condyle in the setting of varus malalignment at a long-term follow-up. It was hypothesized that undergoing combined OAT and valgus HTO would produce favorable clinical results along with a low rate of conversion to arthroplasty., Study Design: Case series; Level of evidence, 4., Methods: All patients treated between 1998 and 2008 with combined valgus HTO and OAT for deep osteochondral defects of the medial femoral condyle and concomitant varus malalignment >2° without meniscal repair/transplantation, osteoarthritis, or ligamentous instability/reconstruction were included. The survival rates of this combined procedure were evaluated. Failure was defined as conversion to knee joint arthroplasty during the follow-up period. Patient-reported outcomes were collected pre- and postoperatively, including the Lysholm score, visual analog scale score, Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity Scale score, and subjective level of satisfaction (scale 0-10)., Results: Of 74 patients who were included for 10-year follow-up, 3 had died. A total of 15 patients were lost to follow-up, so 56 patients could be reevaluated, for a follow-up rate of nearly 80%. The mean age at surgery was 38.8 ± 9.9 years (range, 19.9-62.4 years), and the mean follow-up time was 18.9 ± 3.0 years (median, 18.8 years; range, 14.1-24.8 years). The survival rates were 87% at 10 years, 86% at 15 years, and 77% at 19 years after surgery. At final follow-up, the Lysholm score showed a mean increase of 39 points (95% CI, 25.4-50.0 points; P < .001) from 40 points to 79 points, representing a significant improvement. Overall, 96% of patients surpassed the minimal clinically important difference (MCID) for the Lysholm score. The visual analog scale score decreased by a mean of 4.8 points (range, 5-10 points) from 7.5 points to 2.7 points ( P < .001), and 80% of patients surpassed the MCID. The mean Tegner Activity Scale score was 4.5 ± 1.6, and the mean KOOS subscale scores at final follow-up were as follows: Pain: 81 ± 21 (range, 19-100), Symptoms: 80 ± 22 (range, 21-100), Activities of Daily Living: 85 ± 21 (range, 18-100), Sports: 68 ± 32 (range, 0-100), and Quality of Life: 67 ± 28 (range, 0-100). Overall, 78% of the patients were satisfied with the results of the operation., Conclusion: The combination of OAT and valgus HTO presents a viable treatment option for patients affected by osteochondral defects of the medial femoral condyle and concurrent varus malalignment. A sustained and substantial improvement in clinical outcomes, significantly reduced pain severity, and a high rate of long-term survivorship can be anticipated in the long-term follow-up., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: S.S. is a consultant for Arthrex GmbH, medi GmbH & Co KG, and KLS Martin Group. A.B.I. is a consultant for Arthrex Inc. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Fresh osteochondral allograft (OCA) transplantation is an effective technique for the treatment of focal chondral and osteochondral defects in the knee. Coronal-plane malalignment leads to increased contact forces within a compartment and subsequently the cartilage repair site and may lead to higher failure rates. However, the magnitude of the effect of coronal-plane malalignment on graft survivorship and clinical outcomes has not been well characterized., Purpose: To evaluate how varus malalignment affects graft survival and patient-reported outcomes after isolated OCA transplantation of the medial femoral condyle (MFC)., Study Design: Cohort study; Level of evidence, 3., Methods: A total of 70 patients (74 knees) who underwent primary OCA transplantation of the MFC between 2005 and 2019 were identified from a prospectively collected single-surgeon cartilage registry with a minimum 2-year follow-up. Coronal-plane alignment was evaluated utilizing standing hip-to-ankle radiographs. OCA failure, defined as removal of the graft or conversion to arthroplasty, and reoperations were recorded. Patient-reported outcomes were obtained preoperatively and postoperatively using the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, modified Merle d'Aubigné-Postel score, and overall patient satisfaction score., Results: The mean mechanical tibiofemoral angle for patients with varus alignment was 3.9° of varus (range, 1.1° to 8.9°) and for patients with nonvarus alignment it was 0.02° of valgus (range, 3.6° varus to 4.6° valgus). Graft survivorship was 95.3% in the varus group and 95.8% in the nonvarus group ( P = .918) at 5 years postoperatively. Reoperations after OCA transplantation occurred in 14.0% of the varus group and 22.6% of the nonvarus group ( P = .336). The mean International Knee Documentation Committee total score improved from 45.2 preoperatively to 74.8 at latest follow-up in the varus group and from 40.5 preoperatively to 72.3 at latest follow-up in the nonvarus group. Patient satisfaction was >85%., Conclusion: Patients undergoing isolated OCA transplantation of the MFC had high rates (>90%) of graft survivorship and significant improvements in pain and function. Patients with mild preexisting varus malalignment were found to have no difference in the failure rate or clinical outcomes compared with patients with nonvarus alignment., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: T.W. has received research support from Miach Orthopaedics and holds stock or stock options in Overture Orthopaedics. S.L.G. has received support for education from Zimmer Biomet and CDC Medical, hospitality payments from Acumed, and a grant from Arthrex. J.C.M. has received consulting fees from JRF Ortho. W.D.B. has received consulting fees from JRF Ortho, Arthrex, DePuy Synthes, DePuy Orthopaedics, Encore Medical, Medical Device Business Services, Bioventus, Smith & Nephew, Insight Medical Systems, and OrthAlign; royalties from DePuy Synthes, Smith & Nephew, and Encore Medical; and honoraria from Insight Medical Systems. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Accumulating evidence suggests that synovial inflammation plays a pivotal role in knee osteoarthritis. Although biomechanical findings have shown that medial open-wedge proximal tibial osteotomy (OWPTO) decreases medial compartment loading by correcting knee alignment, the relationship between knee alignment and synovial inflammation in the biological microenvironment has not yet been elucidated., Purposes: To investigate the relationship between preoperative and postoperative knee alignment and synovial gene expression and to determine the cutoff point of postoperative knee alignment at which gene expression of synovial inflammation improves., Study Design: Cohort study; Level of evidence, 3., Methods: A total of 36 patients with osteoarthritis who underwent OWPTO between June 2018 and May 2020 were enrolled. Synovial tissue was collected from affected knees during initial OWPTO and plate removal surgeries, and gene expression associated with the pathogenesis of osteoarthritis in the synovial tissue was investigated using real-time polymerase chain reaction. The correlation between weightbearing line ratio (WBLR) and synovial gene expression was determined. Receiver operating characteristic curve analysis was used to determine the cutoff values of WBLR for improving gene expression. The participants were divided into 2 groups, according to the cutoff values of their WBLR, and compared according to Knee injury and Osteoarthritis Outcome Score (KOOS) and synovial gene expression., Results: Postoperative WBLR was correlated with gene expression of interleukin 1β ( IL1B ) (ρ = -0.43; P = .008) and of interleukin 6 ( IL6 ) (ρ = -0.41; P = .01). The cutoff value to predict improvement of IL6 was postoperative WBLR of 52%, with an area under the curve of 0.74 ( P = .03). Patients with WBLR of <52% showed higher postoperative inflammatory gene ( IL1B [ P = .04] and IL6 [ P = .03]) and inferior postoperative KOOS values compared with those with WBLR of >52%., Conclusion: The novel cutoff alignment for biological improvement after OWPTO in patients with medial compartment osteoarthritis was determined to be WBLR of 52%, and WBLR of <52% was associated with higher residual intra-articular inflammation and poor clinical outcomes. After accounting for surgical errors, the surgeon should set the target surgical alignment so that the postoperative WBLR does not fall below 52%., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This work was supported by Grant-in-Aid for Scientific Research from Japan Society for the Promotion of Science (grant No. 18H02927, 20K09408, 21H03053). The Department of Advanced Medicine for Rheumatic Diseases is supported by Nagahama City, Shiga, Japan; Toyooka City, Hyogo, Japan; and 2 pharmaceutical companies (Asahi Kasei Pharma Corp and AYUMI Pharmaceutical Co). K.N. has received a research grant from Asahi Kasei Pharma Corp and speaking and/or consulting fees from AbbVie GK, Eisai Co Ltd, Pfizer Inc, Chugai Pharmaceutical Co Ltd, Mitsubishi Tanabe Pharma Corporation, Pfizer Inc, Bristol-Myers Squibb, Daiichi Sankyo Co Ltd, and Asahi Kasei Pharma Corp. S.K. has received a research grant from Olympus-Terumo Biomaterials Corp. T.F. has received speaking fees from AbbVie GK, Asahi Kasei Pharma Corp, Chugai Pharmaceutical Co Ltd, Eisai Co Ltd, and Janssen Pharmaceutical K.K. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: In addition to the integrity of the meniscal hoop function, both the anterior and posterior meniscus roots as well as the meniscotibial and meniscofemoral ligaments are crucial in restraining meniscal extrusion. However, the interaction and load sharing between the roots and these peripheral attachments (PAs) are not known., Purposes: To investigate the influence of an insufficiency of the PAs on the forces acting on a posterior medial meniscus root repair (PMMRR) in both neutral and varus alignment and to explore whether meniscal centralization reduces these forces., Study Design: Controlled laboratory study., Methods: In 8 fresh-frozen human cadaveric knees, an arthroscopic transosseous root repair (step 1) was performed after sectioning the posterior root of the medial meniscus. The pull-out suture was connected to a load cell to allow measurement of the forces acting on the root repair. A medial closing-wedge distal femoral osteotomy was performed to change the mechanical axis from neutral to 5° of varus alignment. The meniscus was completely released from its PAs (step 2), followed by transosseous arthroscopic centralization (step 3). Each step was tested in both neutral and varus alignment. The specimens were subjected to nondestructive dynamic varus loading under axial compression of 300 N in 0°, 15°, 30°, 45°, and 60° flexion. The changes in force acting on the PMMRR were statistically analyzed using a mixed linear model., Results: Axial loading in neutral alignment led to an increase of the force of root repair of 3.1 ± 3.1 N (in 0° flexion) to 6.3 ± 4.4 N (in 60° flexion). In varus alignment, forces increased significantly from 30° (3.5 N; 95% CI, 1.1-5.8 N; P = .01) to 60° (7.1 N; 95% CI, 2.7-11.5 N; P = .007) flexion, in comparison with neutral alignment. Cutting of the PAs in neutral alignment led to a significant increase of root repair forces in all flexion angles, from 7.0 N (95% CI, 1.0-13.0 N; P = .02) to 9.1 N (95% CI, 4.1-14.1 N; P = .003), in comparison with the intact state. Varus alignment significantly increased the forces in the cut states from 4.8 N (95% CI, 1.0-8.5 N; P = .02) to 11.1 N (95% CI, 4.2-18.0 N; P = .006) from 30° to 60° flexion, in comparison with the neutral alignment. Arthroscopic centralization led to restoration of the native forces in both neutral and varus alignment, with no significant differences between the centralized and intact states., Conclusion: An insufficiency of the PAs of the medial meniscus, as well as varus alignment, led to increased forces acting on a PMMRR. These forces were reduced via an arthroscopic meniscal centralization., Clinical Relevance: Performing arthroscopic meniscal centralization concomitantly with PMMRR may reduce failure of the repair by reducing the load of the root., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Matrix-induced autologous chondrocyte implantation (MACI), the third-generation of the technique, is an established procedure for the treatment of focal cartilage defects in the knee. However, the literature lacks long-term results of MACI with good statistical power., Purpose: To determine long-term survival and patient-reported outcomes (PROs) in a representative cohort and to identify patient- and surgery-related parameters that may influence long-term clinical outcomes., Study Design: Case series; Level of evidence, 4., Methods: A total of 103 patients were clinically evaluated at the current follow-up of 8.1 years (range, 5-11.9 years). PRO measures (PROMs) included the Knee injury and Osteoarthritis Outcome Score (KOOS), EQ-5D, visual analog scale for pain, and Tegner Activity Scale. Magnetic resonance imaging results were evaluated by using the AMADEUS (area measurement and depth and underlying structures) and MOCART (magnetic resonance observation of cartilage repair tissue) 2.0 knee score classification systems. Potential factors influencing PROs were first identified univariately and investigated in a multivariate regression model., Results: The defects had a mean size of 4.8 cm 2 (range, 1.2-12 cm 2 ) and were predominantly femorotibial (66%). The mean Kaplan-Meier survival rate of revision for any reason was 97.2% ± 1.6% at 10 years. In comparison to preoperative values, all PROMs were significantly improved at the current follow-up ( P < .05). The MOCART 2.0 score peaked at 12 months (mean, 80.2 ± 15.3 months) and showed no significant change at 96 months (mean, 76.1 ± 19.5 months; P = .142). The linear multivariate regression model identified an association of body mass index (BMI), MOCART 2.0 score, and number of previous knee surgeries with KOOS ( R 2 = 0.41; f 2 = 0.69). Further analysis of the individual determinants revealed an optimal BMI range of 20 to 29 for favorable PROs at 96 months. Significant correlations of MOCART subscores with the overall KOOS were found for graft surface and structure, bony reaction, and subchondral detectable changes. Only 30% of patients with 2 previous surgeries and 20% of patients with 3 previous surgeries achieved a Patient Acceptable Symptom State ( χ 2 = 10.93; P = .012)., Conclusion: The present study shows consistently good long-term clinical outcomes after MACI with a low revision rate and high patient satisfaction. BMI and number of previous knee surgeries may influence clinical outcomes and should be considered in patient selection and education. There is a correlation between graft structure, subchondral bone changes on magnetic resonance imaging, and long-term PROMs., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: T.R. has received research funding at personal disposal from DePuy, Zimmer, Aesculap, German Federal Ministry of Education and Research, Deutsche Arthrose-Hilfe, OttoBock-Stiftung, German Federal Ministry of Economic and Development, Oskar-Helene-Heim Foundation in Berlin, Vielberth Foundation, and Deutsche Forschungsgemeinschaft (DFG); and reimbursement of costs from DePuy, Zimmer, and Aesculap. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Data are lacking as to when a meniscal allograft transplant (MAT) may be biomechanically superior to a partially resected lateral meniscus., Hypothesis: Lateral MAT using a bone bridge technique would restore load distribution and contact pressures in the tibiofemoral joint to levels superior to those of a partial lateral meniscectomy., Study Design: Controlled laboratory study., Methods: Eleven fresh-frozen human cadaveric knees were evaluated in 5 lateral meniscal testing conditions (native, one-third posterior horn meniscectomy, two-thirds posterior horn meniscectomy, total meniscectomy, MAT) at 3 flexion angles (0°, 30°, and 60°) under a 1600-N axial load. Pressure sensors were used to acquire contact pressure, contact area, and peak contact pressure within the tibiofemoral joint., Results: Limited (one-third and two-thirds) partial lateral posterior horn meniscectomy showed no significant increase in mean and peak contact pressures as well as no significant decrease in contact area compared with the intact state. Total meniscectomy significantly increased mean contact pressure at 0° and 30° ( P = .008 and P < .001, respectively), increased peak contact pressure at 30° ( P = .04), and decreased mean contact area in all flexion angles compared with the native condition ( P < .01). Lateral MAT significantly improved mean contact pressure compared with total meniscectomy at 0° and 30° ( P = .002 and P = .003, respectively) and increased contact area at 30° and 60° ( P = .003 and P = .009, respectively), although contact area was still significantly smaller (24.1%) after MAT relative to the native meniscus (P = 0.015). However, allograft transplant did not result in better tibiofemoral contact biomechanics compared with limited partial meniscectomy ( P > .05)., Conclusion: The peripheral portion of the lateral meniscus provided the most important contribution to the distribution of contact pressure across the tibiofemoral joint in the cadaveric model. Total meniscectomy significantly increased mean and peak contact pressure in the cadaveric model and decreased contact area. Lateral MAT restored contact biomechanics close to normal but was not superior to the partially meniscectomized status., Clinical Relevance: Surgeons should attempt to preserve a peripheral rim of the posterior lateral meniscus. Meniscal allograft transplant appears to improve but not normalize mean contact pressure and contact area relative to total lateral meniscectomy., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A.H.G. has received consulting fees from Zimmer Biomet, Smith & Nephew, Aastrom Biosciences, Aesculap Biologics, Geistlich Pharma, Genzyme Corp, and Sanofi-Aventus; travel payments from Lifenet Health, Fidia Pharmal, and Stryker; and honoraria from Vericel. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Bone-patellar tendon-bone (BPTB) and double-looped semitendinosus and gracilis (hamstring) grafts are commonly used for anterior cruciate ligament (ACL) reconstruction. Short-term and midterm studies show little or no differences between the 2 grafts; however, there are only a few long-term studies to compare results between the 2 grafts., Purpose: To compare the results after using either BPTB grafts or hamstring tendon grafts 18 years after ACL reconstruction., Study Design: Randomized controlled trial; Level of evidence 2., Methods: A total of 114 patients with ACL rupture between 2001 and 2004 were randomized to reconstruction with either a BPTB graft or a hamstring tendon graft. Patients were operated on at 4 major hospitals. The 18-year follow-up evaluation included anterior knee laxity measured with a KT-1000 arthrometer, defined as the primary outcome, while clinical examination (Lachman and pivot-shift tests), isokinetic testing of muscle strength, patient-reported outcome measures, and an assessment of radiographic osteoarthritis using the Kellgren-Lawrence classification were defined as secondary outcomes., Results: A total of 96 patients (84%, 47 BPTB and 49 hamstring grafts) were available for follow-up, 71 of these for clinical examination. Seven of 96 patients were excluded for ACL revision (n = 5) or knee replacement (n = 2) surgery. In total, 25 patients (10 BPTB and 15 hamstring grafts) had undergone additional surgery other than ACL revision or total knee arthroplasty. There were no significant differences between the groups in terms of anterior laxity test with KT-1000 arthrometer (primary outcome). In secondary outcomes, no significant differences between groups were reported regarding clinical examination, patient-reported outcome scores, or radiographic osteoarthritis (Kellgren-Lawrence grade 2-4 for patellofemoral joint [18 hamstring and 14 BPTB] or tibiofemoral joint [20 hamstring and 19 BPTB]), while isokinetic testing revealed that the hamstring group had a 10.7% reduction in mean peak flexion torque compared with the BPTB group at 60 deg/s ( df = 59; P = .011). At 60 deg/s the mean total flexion work in the hamstring group was reduced by 17.2% compared with the BPTB group ( df = 59; P = .002)., Conclusion: The flexion strength in the hamstring group was significantly reduced in the operated knee after 18 years. There were no significant differences between the groups regarding subjective outcomes, patient-reported outcomes, range of motion, clinical and instrumented knee laxity, and the development of osteoarthritis., Registration: NCT05876013 (ClinicalTrials.gov identifier)., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Although high tibial osteotomy (HTO) has emerged as a powerful intervention for treating symptomatic medial osteoarthritis and varus malalignment, it can result in an increase in knee joint line obliquity (KJLO) in the frontal plane. Limited current evidence hinders understanding of the effect of increased KJLO on HTO survivorship., Purpose: To investigate the influence of KJLO and other potential risk factors on the survivorship of lateral closing-wedge HTO., Study Design: Cohort study; Level of evidence, 3., Methods: Patients with symptomatic medial knee osteoarthritis and varus malalignment treated with lateral closing-wedge HTO at a single hospital were screened with a minimum follow-up of 5 years. HTO survival rate was assessed using Kaplan-Meier survival analysis. The influence of postoperative increased KJLO (medial proximal tibial angle ≥95°), age (≥55 years), sex (female), preoperative malalignment (hip-knee-ankle angle ≥10° of varus), postoperative untargeted alignment (hip-knee-ankle angle <2° or >6° of valgus), and preoperative osteoarthritis severity (Kellgren-Lawrence grade ≥3) on survivorship of HTO was evaluated using Cox regression analysis. A failure of HTO was defined as a conversion to total knee arthroplasty (TKA)., Results: A total of 410 patients (463 knees) were included, with a mean follow-up of 13.0 years (range, 5.0-18.1 years) and a mean survival time of 11.2 years (range, 1.2-18.1 years) for patients who reached the endpoint of TKA. HTO survival rates at 5, 10, and 15 years postoperatively were 91%, 78%, and 60%, respectively. Multivariate Cox regression analysis showed no significant difference in survivorship between patients with increased KJLO and those with acceptable KJLO (178 vs 285 knees; hazard ratio [HR], 0.8; 95% CI, 0.6-1.1; P = .148), with no significant between-group difference observed in the mean follow-up length (12.9 ± 3.0 years vs 13.1 ± 3.3 years; P = .105). Female sex (HR, 2.0; P < .001) and postoperative untargeted alignment (HR, 1.6; P = .003) were risk factors for a conversion to TKA., Conclusion: Increased postoperative KJLO (medial proximal tibial angle ≥95°) had no significant influence on the survivorship of lateral closing-wedge HTO. Men demonstrated superior survival outcomes compared with women, and it was important to achieve a targeted postoperative alignment (HKA 2°-6° of valgus) to ensure favorable HTO survivorship., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Osteochondral allograft (OCA) transplantation is an important surgical technique for full-thickness chondral defects in the knee. For patients undergoing this procedure, topography matching between the donor and recipient sites is essential to limit premature wear of the OCA. Currently, there is no standardized process of donor and recipient graft matching., Purpose: To evaluate a novel topography matching technique for distal femoral condyle OCA transplantation using 3-dimensional (3D) laser scanning to create 3D-printed patient-specific instrumentation in a human cadaveric model., Study Design: Descriptive laboratory study., Methods: Human cadaveric distal femoral condyles (n = 12) underwent 3D laser scanning. An 18-mm circular osteochondral recipient defect was virtually created on the medial femoral condyle (MFC), and the position and orientation of the best topography-matched osteochondral graft from a paired donor lateral femoral condyle (LFC) were determined using an in silico analysis algorithm minimizing articular step-off distances between the edges of the graft and recipient defect. Distances between the entire surface of the OCA graft and the underneath surface of the MFC were evaluated as surface mismatch. Donor (LFC) and recipient (MFC) 3D-printed patient-specific guides were created based on 3D reconstructions of the scanned condyles. Through use of the guides, OCAs were harvested from the LFC and transplanted to the reamed recipient defect site (MFC). The post-OCA recipient condyles were laser scanned. The 360° articular step-off and cartilage topography mismatch were measured., Results: The mean cartilage step-off and graft surface mismatch for the in silico OCA transplant were 0.073 ± 0.029 mm (range, 0.005-0.113 mm) and 0.166 ± 0.039 mm (range, 0.120-0.243 mm), respectively. Comparatively, the cadaveric specimens postimplant had significantly larger step-off differences (0.173 ± 0.085 mm; range, 0.082-0.399 mm; P = .001) but equivalent graft surface topography matching (0.181 ± 0.080 mm; range, 0.087-0.396 mm; P = .678). All 12 OCA transplants had mean circumferential step-off differences less than a clinically significant cutoff of 0.5 mm., Conclusion: These findings suggest that the use of 3D-printed patient-specific guides for OCA transplantation has the ability to reliably optimize cartilage topography matching for LFC to MFC transplantation. This study demonstrated substantially lower step-off values compared with previous orthopaedic literature when also evaluating LFC to MFC transplantation. Using this novel technique in a model performing MFC to MFC transplantation has the potential to yield further enhanced results due to improved radii of curvature matching., Clinical Relevance: Topography-matched graft implantation for focal chondral defects of the knee in patients improves surface matching and has the potential to improve long-term outcomes. Efficient selection of the allograft also allows improved availability of the limited allograft sources., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) funded this investigation. A.A.E.O. has received financial or material support from Stryker. M.H. has received consulting fees from DJO-Enovis, Moximed, and Vericel; honoraria from Encore Medical; support for education from Arthrex and Foundation Medical; and hospitality payments from Stryker and Medical Device Business Services. B.J.C. has received research support from Aesculap/B.Braun, Arthrex, and Regentis; consulting fees from Arthrex, DJO, and Samumed; royalties from Arthrex; financial or material support from Athletico, JRF Ortho, and Smith & Nephew; and holds stock and stock options in Bandgrip Inc, Ossio, and Regentis. A.B.Y. has received consulting fees from AlloSource, JRF Ortho, and Stryker; research support from Arthrex and Organogenesis; holds stock or stock options in Patient IQ, Sparta Biomedical, and Icarus; and is an unpaid consultant for Patient IQ and Sparta Biomedical. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Cartilage transplantation is commonly used to treat large (>4 cm 2 ) articular cartilage defects of the knee. The 2 most common transplants are osteochondral allograft transplantation and autologous chondrocyte implantation. Several patient-reported outcome measures (PROMs) have been used to determine the efficacy of treatment, but it is unknown which measures are the most effective., Purpose: To report the multiple PROMs used after large knee articular cartilage transplantation surgery and to compare the responsiveness between them., Study Design: Meta-analysis; Level of evidence, 4., Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search of the PubMed/MEDLINE and Web of Science databases was performed. A total of 181 articles met inclusion criteria. Patient and study characteristics were extracted, including pre- and postoperative means for PROMs. From the articles that met inclusion criteria for responsiveness analysis (2+ PROMs reported, 1-year minimum follow-up, reported pre- and postoperative means and standard deviations; n = 131), the authors compared the responsiveness between PROM instruments using effect size and relative efficiency (RE) if a PROM could be compared with another in ≥10 articles., Results: A total of 10,015 patients (10,093 knees; mean age, 34.8 years; mean body mass index, 26.1) were included in this study. The mean follow-up time was 58.3 months (range, 1.5-247.2 months), imaging findings were reported in 80 articles (44.2%), patient satisfaction was reported in 39 articles (21.5%), and range of motion was reported in 10 articles (5.5%). There were 58 unique PROM instruments identified, with the most used being the International Knee Documentation Committee (IKDC) score (n = 118; 65.2%), followed by Knee injury and Osteoarthritis Outcome Score (KOOS) Pain (n = 58; 32.0%), KOOS Sport and Recreation (n = 58; 32.0%), KOOS Quality of Life (n = 57; 31.5%), KOOS Activities of Daily Living (n = 57; 31.5%), and KOOS Symptoms (n = 57; 31.5%). Overall, IKDC was found to have the greatest effect size (1.68) and the best responsiveness of the other PROMs, which include KOOS Pain (RE, 1.38), KOOS Symptoms (RE, 3.06), KOOS Activities of Daily Living (RE, 1.65), KOOS Sport and Recreation (RE, 1.44), Lysholm (RE, 1.76), and Tegner (RE, 1.56)., Conclusion: The IKDC is the most responsive PROM after large knee articular cartilage transplantation surgery. The IKDC score is recommended for assessing outcomes after cartilage transplantation surgery., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A.V.S. has received speaking fees from Smith & Nephew; support for education from Legacy Ortho, Arthrex, Medwest Associates, and Stryker; and hospitality payments from Wright Medical Technologies. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Anterior cruciate ligament injury and anterior cruciate ligament reconstruction (ACLR) are risk factors for symptomatic posttraumatic osteoarthritis (PTOA). After ACLR, individuals demonstrate altered joint tissue metabolism indicative of increased inflammation and cartilage breakdown. Serum biomarker changes have been associated with tibiofemoral cartilage composition indicative of worse knee joint health but not with PTOA-related symptoms., Purpose/hypothesis: The purpose of this study was to determine associations between changes in serum biomarker profiles from the preoperative sample collection to 6 months after ACLR and clinically relevant knee PTOA symptoms at 12 months after ACLR. It was hypothesized that increases in biomarkers of inflammation, cartilage metabolism, and cartilage degradation would be associated with clinically relevant PTOA symptoms after ACLR., Study Design: Case-control study; Level of evidence, 3., Methods: Individuals undergoing primary ACLR were included (N = 30). Serum samples collected preoperatively and 6 months after ACLR were processed to measure markers indicative of changes in inflammation (ie, monocyte chemoattract protein 1 [MCP-1]) and cartilage breakdown (ie, cartilage oligomeric matrix protein [COMP], matrix metalloproteinase 3, ratio of type II collagen breakdown to type II collagen synthesis). Knee injury and Osteoarthritis Outcome Score surveys were completed at 12 months after ACLR and used to identify participants with and without clinically relevant PTOA-related symptoms. K-means cluster analyses were used to determine serum biomarker profiles. One-way analyses of variance and logistic regressions were used to assess differences in Knee injury and Osteoarthritis Outcome Score subscale scores and clinically relevant PTOA-related symptoms between biomarker profiles., Results: Two profiles were identified and characterized based on decreases (profile 1: 67% female; age, 21.4 ± 5.1 years; body mass index, 24.4 ± 2.4) and increases (profile 2: 33% female; age, 21.3 ± 3.2 years; body mass index, 23.4 ± 2.6) in sMCP-1 and sCOMP preoperatively to 6 months after ACLR. Participants with profile 2 did not demonstrate differences in knee pain, symptoms, activities of daily living, sports function, or quality of life at 12 months after ACLR compared to those with profile 1 ( P = .56-.81; η 2 = 0.002-0.012). No statistically significant associations were noted between biomarker profiles and clinically relevant PTOA-related symptoms (odds ratio, 1.30; 95% CI, 0.23-6.33)., Conclusion: Serum biomarker changes in MCP-1 and sCOMP within the first 6 months after ACLR were not associated with clinically relevant PTOA-related symptoms., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: Research reported in this manuscript was supported by funding from the University of North Carolina's Department of Orthopaedics Laurence E. Dahners Research Grant, the National Institute of Arthritis and Musculoskeletal and Skin Disease of the National Institutes of Health (1R03 AR066840-01A1 and P30 AR072580), the North Carolina Translational and Clinical Sciences (TraCS) Institute, and the National Athletic Trainers’ Association Research and Education Foundation (14NewINV001). R.A.C. has received consulting fees from Arthrex and support for education from SouthTech Orthopedics. G.K. has received compensation for services other than consulting from Arthrex. J.S. has received support for education from SouthTech Orthopedics. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: In carefully selected patients with an arthritic valgus knee, distal femoral osteotomy (DFO) can improve symptoms at medium- to long-term follow-up, reducing osteoarthritis progression. To date, there is no clear evidence in the current literature regarding the role of postoperative joint line obliquity (JLO) in valgus deformity correction., Purpose: To assess the clinical and radiological outcomes of medial closing-wedge DFO (MCW-DFO) for the treatment of valgus knees, considering both tibial- and femoral-based deformities, as well as to verify the efficacy and safety of MCW-DFO according to JLO boundaries (≤4°)., Study Design: Cohort study; Level of evidence, 3., Methods: A retrospective analysis was conducted on a cohort of patients with valgus knees. Patients were divided into 2 groups: femoral-based valgus (FB-V) and tibial-based valgus (TB-V). Knee radiographs were collected before surgery and at the last follow-up. The clinical outcome was evaluated through several validated scores (International Knee Documentation Committee, Knee Society Score, Knee injury and Osteoarthritis Outcome Score, Tegner, Numeric Rating Scale, Crosby-Insall)., Results: A total of 30 patients (34 knees) with a mean age of 49.3 ± 9.1 years were included in the study. The overall mean follow-up was 9.4 ± 5.9 years. The mean preoperative hip-knee-ankle angle was 187.6°± 3.3° (range, 181.5°-191°) and the postoperative angle was 180°± 3.1° (range, 176°-185°). Most postoperative JLOs were within the safe zone of ≤4° in both groups (the postoperative JLO was >4° in 4 patients in the TB-V group and 1 patient in the FB-V group), although FB-V knees exhibited significant superior JLO correction (postoperative JLO in the TB-V group: mean, 4.0°± 2.5° [ P = .1]; postoperative JLO in the FB-V group: mean, 2.4°± 1.4° [ P = .5]). Significant improvements in all clinical scores were observed in both groups ( P < .01). Additionally, the severity of the osteoarthritis did not worsen at the last follow-up., Conclusion: MCW-DFO is an effective procedure for treating pathological valgus knees, regardless of the site of the deformity. Both FB-V and TB-V groups showed comparable improvements in the clinical scores, development of osteoarthritis, and the restoration of a neutral mechanical axis. Notably, FB-V knees achieved more JLO correction compared with the TB-V ones., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: The outcomes of medial meniscal allograft transplantation (MMAT) combined with high tibial osteotomy (HTO) compared with isolated MMAT remain unclear., Purpose: To compare the clinical and radiological results of MMAT combined with HTO and isolated MMAT., Study Design: Cohort study; Level of evidence, 3., Methods: This retrospective study included 42 consecutive patients, who were divided into group M (isolated MMAT; n = 22) and group H (MMAT combined with HTO with a varus angle >3°; n = 20). Group differences in subjective knee scores, isokinetic muscle strength test, and radiological outcomes (Kellgren-Lawrence grade, mechanical axis, graft extrusion, graft status, and articular cartilage loss) were compared., Results: The mean follow-up period was 29.2 ± 4.9 months and 27.4 ± 5.3 months for groups M and H, respectively. The Lysholm score improved from 55.4 ± 9.5 to 81.3 ± 9.7 and from 52.6 ± 8.9 to 84.2 ± 10.2 in groups M and H, respectively (both P < .001). The International Knee Documentation Committee subjective score improved from 51.4 ± 10.3 to 79.6 ± 9.4 and from 49.3 ± 11.4 to 81.4 ± 8.3 in groups M and H, respectively (both P < .001). Both groups showed no significant differences in subjective knee scores and isokinetic extensor strength at the final follow-up. The rate of preoperative and postoperative high International Cartilage Regeneration & Joint Preservation Society grade (≥3) did not differ between the 2 groups. Group M showed greater coronal graft extrusion than did group H (3.3 ± 0.7 mm vs 2.7 ± 0.8 mm; P = .014); the rate of pathologic graft extrusion (≥3 mm) was not higher in group M (40.9%) than in group H (20%) with the number of patients available ( P = .143). Both groups showed no significant difference in the graft status. Graft tears were observed in 2 patients (9%) in group M and 1 patient (5%) in group H ( P = .607)., Conclusion: Clinical scores significantly improved after isolated MMAT and MMAT combined with HTO compared with preoperative values, and their short-term outcomes were similar. Postoperative graft extrusion was greater in patients who underwent isolated MMAT, implying that active correction of varus alignment during MMAT may help in intra-articular biomechanics., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: There is still debate regarding the association between arthrometric knee laxity measurements and subjective knee outcome and revision surgery after primary anterior cruciate ligament reconstruction (ACLR)., Purpose: To assess whether arthrometric knee laxity (measured with the KT-1000 arthrometer) 6 months after primary ACLR was associated with the 1-, 2-, and 5-year subjective knee outcomes or revision ACLR at a 5-year follow-up., Study Design: Cohort study, Level of evidence 3., Methods: Patients who underwent primary ACLR with a hamstring tendon autograft at the authors' institution between January 1, 2005, and December 31, 2017, with no concomitant ligamentous injuries, were identified. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1, 2, and 5 years postoperatively. Patients who underwent revision ACLR at any institution in the country within 5 years of primary surgery were identified through the Swedish National Knee Ligament Registry., Results: A total of 4697 patients (54.3% male) with available KT-1000 arthrometer measurements were included (normal: side-to-side [STS] ≤2 mm, 3015 [64.2%]; nearly normal: STS 3-5 mm, 1446 [30.8%]; abnormal: STS >5 mm, 236 [5.0%]). The only significant difference in subjective knee outcome between the groups was for the KOOS Symptoms subscale at the 1-year follow-up (STS ≤2 mm, 79.9 ± 16.2; STS 3-5 mm, 82.5 ± 14.8; STS >5 mm, 85.1 ± 14.2; P < .001). No other significant differences between the groups were found preoperatively or at 1, 2, or 5 years postoperatively for any of the KOOS subscales. The hazard for revision ACLR within 5 years of the primary surgery was significantly higher for the groups with an STS of 3 to 5 mm (6.6%; 95/1446) (hazard ratio [HR], 1.42; 95% CI, 1.07-1.87; P = .01) and an STS >5 mm (11.4%; 27/236) (HR, 2.61; 95% CI, 1.69-4.03; P < .001) compared with the group with an STS ≤2 mm (3.8%; 116/3015)., Conclusion: A high grade of postoperative knee laxity (STS 3-5 mm and STS >5 mm) 6 months after primary ACLR was associated with an increased hazard of revision ACLR within 5 years, but it was not associated with an inferior subjective knee outcome., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: New techniques have been proposed to better address anteromedial rotatory instability in a medial collateral ligament (MCL)-injured knee that require an extra graft and more surgical implants, which might not be feasible in every clinical setting., Purpose: To investigate if improved resistance to anteromedial rotatory instability can be achieved by using a single-graft, double-bundle (DB) MCL reconstruction with a proximal fixation more anteriorly on the tibia, in comparison with the gold standard single-bundle (SB) MCL reconstruction., Study Design: Controlled laboratory study., Methods: Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic simulator in intact knee, superficial MCL/deep MCL-deficient, and reconstruction states. Three different reconstructions were tested: DB MCL no proximal tibial fixation and DB and SB MCL reconstruction with proximal tibial fixation. Knee kinematics were recorded at 0°, 30°, 60°, and 90° of knee flexion for the following measurements: 8 N·m of valgus rotation (VR), 5 N·m of external tibial rotation, 5 N·m of internal tibial rotation, combined 89 N of anterior tibial translation and 5 N·m of external rotation for anteromedial rotation (AMR) and anteromedial translation (AMT). The differences between each state for every measurement were analyzed with VR and AMR/AMT as primary outcomes., Results: Cutting the superficial MCL/deep MCL increased VR and AMR/AMT in all knee positions except at 90° for VR ( P < .05). All reconstructions restored VR to the intact state except at 90° of knee flexion ( P < .05). The DB MCL no proximal tibial fixation reconstruction could not restore intact AMR/AMT kinematics in any knee position ( P < .05). Adding an anterior-based proximal tibial fixation restored intact AMR/AMT kinematics at ≥30° of knee flexion except at 90° for AMT ( P < .05). The SB MCL reconstruction could not restore intact AMR/AMT kinematics at 0° and 90° of knee flexion ( P < .05)., Conclusion: In this in vitro cadaveric study, a DB MCL reconstruction with anteriorly placed proximal tibial fixation was able to control AMR and AMT better than the gold standard SB MCL reconstruction., Clinical Relevance: In patients with anteromedial rotatory instability and valgus instability, a DB MCL reconstruction may be superior to the SB MCL reconstruction, without causing extra surgical morbidity or additional costs., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: Support was received from Smith & Nephew Inc in the form of a research grant that funded the presented research; Ossur Inc in the form of an educational grant for the authors’ research fellowship position; the Natural Sciences and Engineering Research Council (NSERC) Discovery: RGPIN-2018-05693; the Ontario Early Researcher Award ER18-14-197; and the Canadian Foundation for Innovation JELF and Ontario Research Fund—Research Infrastructure: 38141. A.G. has received consulting fees from Smith & Nephew; is on the advisory board of and holds stock in Spring Loaded Technologies; and holds stock in OS LinkX Robotics and Ostesys Robotics. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Matrix-induced autologous chondrocyte implantation (MACI) is an established cell-based therapy for the treatment of chondral defects of the knee. As long-term outcomes are now being reported in the literature, it is important to systematically review available evidence to better inform clinical practice., Purpose: To report (1) subjective patient-reported outcomes (PROs) and (2) the rate of graft failure, reoperation, and progression to total knee arthroplasty (TKA) after undergoing MACI of the knee at a minimum 10-year follow-up., Study Design: Systematic review; Level of evidence, 4., Methods: A comprehensive search of Ovid MEDLINE and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily; Ovid Embase; Ovid Cochrane Central Register of Controlled Trials; Ovid Cochrane Database of Systematic Reviews; and Scopus from 2008 to September 15, 2022, was conducted in the English language. Study eligibility criteria included (1) full-text articles in the English language, (2) patients undergoing a MACI within the knee, (3) clinical outcomes reported, and (4) a minimum 10-year follow-up., Results: In total, 168 patients (99 male, 69 female; mean age, 37 years [range, 15-63 years]; mean body mass index, 26.2 [range, 18.6-39.4]) representing 188 treated chondral defects at a minimum 10-year follow-up after MACI were included in this review. Significant and durable long-term improvements were observed across multiple PRO measures. Follow-up magnetic resonance imaging (MRI), when performed, also demonstrated satisfactory defect fill and an intact graft in the majority of patients. The all-cause reoperation rate was 9.0%, with an overall 7.4% rate of progression to TKA at 10 to 17 years of follow-up., Conclusion: At a minimum 10-year follow-up, patients undergoing MACI for knee chondral defects demonstrated significant and durable improvements in PROs, satisfactory defect fill on MRI-based assessment, and low rates of reoperation and TKA. These data support the use of MACI as a long-term treatment of focal cartilage defects of the knee., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: Support was received from the Foderaro-Quattrone Musculoskeletal-Orthopaedic Surgery Research Innovation Fund. This study was partially funded by the following: National Institute of Arthritis and Musculoskeletal and Skin Diseases for the Musculoskeletal Research Training Program (T32AR56950). D.B.F.S. has received compensation for services other than consulting from Arthrex, research support from the Joint Restoration Foundation, and consulting fees from NewClip and Smith & Nephew. A.J.K. has received consulting fees from Arthrex, the Joint Restoration Foundation, and Responsive Arthroscopy LLC; royalty or license from Arthrex and Responsive Arthroscopy; a grant from DJO LLC; and honoraria from the Joint Restoration Foundation and Musculoskeletal Transplant Foundation; and he served on the board for the Musculoskeletal Transplant Foundation (through 2018). M.H. has received hospitality payments from Medical Device Business Services and Stryker Corp; education payments from Medwest Associates, Smith & Nephew, and Foundation Medical; honoraria from Encore Medical; and consulting fees from Vericel Corp. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: High tibial osteotomy (HTO) aims to realign the varus knee to alleviate stress in the medial compartment. However, detailed information on the impact of HTO on stress distribution across the tibiofemoral joint surface still needs to be completely elucidated., Purpose/hypothesis: The present study aimed to analyze the subchondral bone density distribution to validate the alignment threshold causing paradoxical changes. We hypothesized that there would be a paradoxical stress change in the medial compartment beyond a specific threshold for lower limb realignment after HTO., Study Design: Case series; Level of evidence, 4., Methods: A retrospective clinical study of 32 knees from 30 patients who underwent medial opening-wedge HTO between 2015 and 2019 was conducted at Hokkaido University Hospital. The subchondral bone density across the tibiofemoral joint was analyzed using computed tomography-osteoabsorptiometry before and after HTO. The high-density area (HDA) within the medial and lateral compartments and their subregions, which were quartered in the coronal plane, was specifically examined., Results: The hip-knee-ankle angle, medial proximal tibial angle (MPTA), joint line obliquity (JLO), and joint line convergence angle significantly changed after HTO ( P < .01). The HDA of the medial compartment to the total HDA ratio decreased from 83% to 77%. Paradoxically, the HDA in the most central subregion of the medial compartment increased from 24% to 30%. There were significant differences between MPTA and JLO in patients with and without paradoxical changes in the HDA. MPTA and JLO cutoff values causing paradoxical changes in the HDA were 94° and 4°, respectively., Conclusion: There was a paradoxical stress increase in the M4 region at the medial compartment associated with the MPTA and JLO beyond specific thresholds. Therefore, surgical planning should be cautiously performed to prevent overcorrection, which can lead to adverse stress distribution changes., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This work was financially supported by grants from the Ministry of Education, Culture, Sports, Science and Technology, Japan (Grant-in-Aid 21K16672). The institution of one of the authors (K.I.) has received funding from Olympus Terumo Biomaterials Corp. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Multilayered osteochondral scaffolds are becoming increasingly utilized for the repair of knee joint surface lesions (KJSLs). However, the literature on predictive factors is rather limited., Purpose: To (1) evaluate the clinical outcomes and safety of a combined single-step approach using a biomimetic collagen-hydroxyapatite scaffold (CHAS) and filtered bone marrow aspirate (fBMA) for the treatment of KJSLs and (2) identify significant predictors of the treatment outcomes., Study Design: Case series; Level of evidence, 4., Methods: All patients who underwent surgery because of a KJSL (size ≥1.5 cm 2 ; International Cartilage Regeneration & Joint Preservation Society grades 3-4) using the combination above were selected from a hospital registry database (100 patients; minimum 2-year follow-up). Patient characteristics, medical history, knee joint and lesion status, intraoperative details, and cellular parameters of the injected fBMA were collected. The arthroscopic evaluation of chondral and meniscal tissue quality in all knee compartments was performed using the Chondropenia Severity Score. Treatment outcomes were determined clinically using patient-reported outcome measures (Knee Injury and Osteoarthritis Outcome Score, EuroQol-5 Dimensions-3 Levels, EuroQol-Visual Analog Scale, and Tegner Activity Scale) and by assessing the occurrence of serious adverse events and graft failure. Multivariable regression analysis was performed to identify significant predictors of the treatment outcomes., Results: At a mean follow-up of 54.2 ± 19.4 months, 78 (87%) patients completed the questionnaires with significant improvements toward the baseline ( P < .00625): KOOS Pain subscale from 62 ± 17 to 79 ± 18, KOOS Total score from 57 ± 16 to 70 ± 20, EuroQol-Visual Analog Scale from 61 ± 21 to 76 ± 16, EuroQol-5 Dimensions-3 Levels from 0.57 ± 0.20 to 0.80 ± 0.21, and Tegner Activity Scale from 2.8 ± 1.5 to 3.9 ± 1.9. The graft failure rate was 4%. A longer duration of preoperative symptoms, previous surgery, larger lesions, older age, and female sex were the main negative predictors for the treatment outcomes. The Chondropenia Severity Score and the number of fibroblast colony-forming units in fBMA positively influenced some of the clinical results and safety., Conclusion: A CHAS augmented with fBMA proved to be an adequate and safe approach for the treatment of KJSLs up to midterm follow-up. Based on the subanalysis of predictive factors, the surgical intervention should be performed in a timely and precise manner to prevent lesion enlargement, deterioration of the general knee cartilage status, and recurrent surgical procedures, especially in older and female patients. When a CHAS is used, the quantity of MSCs seems to play a role in augmentation., Registration: NCT06078072 (ClinicalTrials.gov identifier)., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: M.V. and L.G. are employed by Educell, which is a commercial cell and tissue company that provides separated mesenchymal stem cells and other advanced cell therapies. M.D. is a clinical consultant for Finceramica. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: After posterior cruciate ligament reconstruction (PCLR), functional deficits at the knee can persist. It remains unclear if neighboring joints compensate for the knee during demanding activities of daily living., Purpose: To assess long-term alterations in lower limb mechanics in patients after PCLR., Study Design: Descriptive laboratory study., Methods: A total of 28 patients who had undergone single-bundle unilateral isolated or combined PCLR performed stair navigation, squat, sit-to-stand, and stand-to-sit tasks at 8.2 ± 2.2 years after surgery. Motion capture and force plates were used to collect kinematic and kinetic data. Then, 3-dimensional hip, knee, and ankle kinematic data of the reconstructed limb were compared with those of the contralateral limb using statistical parametric mapping., Results: Side-to-side differences at the knee were primarily found during upward-driven movements at 8 years after surgery. The reconstructed knee exhibited lower internal rotation during the initial loading phase of stair ascent versus the contralateral knee ( P = .005). During the sit-to-stand task, higher flexion angles during the midcycle ( P = .017) and lower external rotation angles ( P = .049) were found in the reconstructed knee; sagittal knee ( P = .001) and hip ( P = .016) moments were lower in the reconstructed limb than the contralateral limb. In downward-driven movements, side-to-side differences were minimal at the knee but prominent at the ankle and hip: during stair descent, the reconstructed ankle exhibited lower dorsiflexion and lower external rotation during the midcycle versus the contralateral ankle ( P = .006 and P = .040, respectively). Frontal hip moments in the reconstructed limb were higher than those in the contralateral limb during the stand-to-sit task ( P = .010); during squats, sagittal hip angles in the reconstructed limb were higher than those in the contralateral limb ( P < .001)., Conclusion: Patients after PCLR exhibited compensations at the hip and ankle during downward-driven movements, such as stair descent, squats, and stand-to-sit. Conversely, residual long-term side-to-side differences at the knee were detected during upward-driven movements such as stair ascent and sit-to-stand., Clinical Relevance: After PCLR, side-to-side differences in biomechanical function were activity-dependent and occurred either at the knee or neighboring joints. When referring to the contralateral limb to assess knee function in the reconstructed limb, concentric, upward-driven movements should be prioritized. Compensations at the hip and ankle during downward-driven movements lead to biases in long-term functional assessments., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: G.N.D. has received consulting fees from Pluristem, DePuy Synthes, Implantec, Implantcast, and Stryker; has grants or grants pending with Pluristem, DePuy Synthes, Implantec, Implantcast, Smith & Nephew, Stryker, and Zimmer; and has patents (planned, pending, or issued) with Pluristem and B&C for work unrelated to this particular study. T.M.J. has received support for education and hospitality payments from Smith & Nephew, Richard Wolf, and DJO Global. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Synovial lipomatosis is a controversial entity of uncommon intraarticular joint lesions. Most studies focused on radiological findings and surgical resection modalities. Pathologic findings were limited to case reports. Detailed descriptions of the histopathologic features are lacking. We aim to highlight the salient histopathologic features of synovial lipomatosis. We performed a retrospective review study over 15 years retrieving cases of synovial lipomatosis. We found 5 patients (age range: 8-78, average age: 50 years, male to female ratio: 4:1) demonstrating unilateral synovial lipomatosis out of 241 (2.0%) patients with knee joint lesions. Four patients had osteoarthritis. One patient was obese. The resected specimens showed synovial hyperplasia, surface fibrin, hemosiderin pigment, microcalcifications, lymphoplasmacytic infiltrates, lymphoid aggregates, stromal fibrotic, degenerative, and metaplastic alterations shared by other synovitis related changes. Consistent features included abundant adipocytic components, surface adipocytes, prominent large vessel vasculatures, plasma cells, and dense perivascular lymphocytic cuff-like infiltrates. One patient demonstrated superimposed sarcoid-type epithelioid granulomas. A distinct fibrous band separated the lesional tissue from the underlying normal fatty tissue. Synovial lipomatosis predominates in older males with degenerative joint conditions with a second peak in children and adolescents. Obesity is not a risk factor. Some histopathologic features help distinguish synovial lipomatosis from look-alike joint lesions. The findings may suggest an angiolipomatous hamartomatous growth or an exaggerated synovial reaction inducing florid subsynovial stromal proliferative, metaplastic, and degenerative changes. Regardless of its etiopathogenesis, pathologists have a role in confirming the diagnosis and ensuring a complete arthroscopic synovectomy by assessing the presence of the fibrous septa., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: This study aims to investigate the impact of varying coronal alignments of femoral prostheses on stress and strain distributions within the lateral compartment following unicompartmental knee arthroplasty (UKA) in patients with normal bone density and osteoporosis using finite element analysis. Additionally, it examines the relationship between osteoporosis and the progression of osteoarthritis in the lateral compartment postoperatively., Methods: UKA models were developed for both normal bone and osteoporotic conditions using a validated finite element model of the knee. Seven alignment conditions for the femoral prosthesis were simulated: 0° (neutral alignment), varus angles of 3°, 6°, and 9°, and valgus angles of 3°, 6°, and 9°, resulting in a total of 14 scenarios. Stress and strain distributions in the meniscus, tibial cartilage, and femoral cartilage of the lateral compartment were evaluated., Results: The results indicated that stress and strain in the meniscus, tibial cartilage, and femoral cartilage of the lateral compartment increased with greater varus alignment and decreased with greater valgus alignment in both normal and osteoporotic models. At equivalent alignment angles, stress and strain were consistently higher in the osteoporotic model (M2) compared to the normal bone model (M1), although the peak equivalent stress in the tibial cartilage was lower in the M2 model than in the M1 model., Conclusions: In patients with osteoporosis undergoing fixed-bearing medial UKA, varus malalignment of the femoral prosthesis can lead to increased stress and strain in the lateral compartment's meniscus, tibial cartilage, and femoral cartilage. These findings suggest that osteoporosis may contribute to abnormal stress and strain distributions in the lateral compartment following UKA, potentially accelerating the progression of osteoarthritis in this region postoperatively., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: The purpose of this study was to evaluate associations between demographics and Coronal Plane Alignment of the Knee (CPAK) classification in pre-surgical TKA patients. Methods: This is a retrospective study of 1167 patients with knee osteoarthritis who underwent TKA. CPAK categories I-IX were determined by arithmetic mechanical hip-knee-ankle angle and joint line obliquity measurements from pre-operative bone length radiographs. Patient age, sex, body mass index (BMI) and race were collected. Chi-square test of independence and adjusted Pearson's residuals evaluated associations between CPAK classification and demographics. Results: There was a significant association between CPAK phenotypes I-IX and patient sex (X 2 = 5.8, p < 0.01). A positive association was found between both men and CPAK phenotype I, and women and CPAK phenotype VII. A positive association was found between African American patients and CPAK phenotype III and a negative association was found between African American patients and CPAK phenotype I (X 2 =14.8, p -value = 0.01). There was no association between age and BMI with CPAK phenotypes (n.s.). Conclusion: These results indicate that there are unidentified sex and race differences that exist in the CPAK classification of native arthritic knees. Patient characteristics play a significant role in determining patient knee phenotypes. Further research should investigate whether these characteristics warrant inclusion in pre-operative preparations, aiming to enhance the personalization of arthroplasty procedures., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Medial opening-wedge high tibial osteotomy (MOWHTO) is performed to treat young adults with medial compartment knee osteoarthritis associated with varus deformity. However, factors influencing joint space width (JSW) vary according to the type of medial meniscal tear and have not yet been completely elucidated., Purpose: To examine changes in JSW according to the type of medial meniscal tear after MOWHTO and analyze the influencing factors., Study Design: Cohort study; Level of evidence, 3., Methods: This study was conducted on 134 patients who underwent MOWHTO for medial osteoarthritis and were followed up for >2 years. The patients were classified into 3 groups based on medial meniscal status: intact, nonroot tear, and root tear. The authors then measured the JSW preoperatively and at 3 months, 6 months, 1 year, and >2 years postoperatively; analyzed whether the change in JSW varied according to meniscal status; and determined the association of these changes with the preoperative cartilage grade of the medial femoral condyle (MFC) and medial tibial plateau (MTP). International Knee Documentation Committee (IKDC) scores were used to evaluate clinical function., Results: Of the 134 patients, the medial meniscus was intact in 29 patients, a nonroot tear was observed in 58 patients, and a root tear was observed in 47 patients. Postoperatively, JSW increased for all groups, but the timing of the increase varied between the groups ( P < .001). JSW increased the most 6 months postoperatively in the intact group and 3 months postoperatively in the nonroot tear and root tear groups ( P < .001). Additionally, the increase in JSW was the greatest in the root tear group. Preoperatively, MFC and MTP cartilage status differed among the groups; MTP status did not affect the JSW, but MFC status did ( P < .001). The IKDC score increased from the preoperative to postoperative time point in all groups, but there was no significant difference between groups., Conclusion: The authors observed that the amount and timing of increase in JSW were dependent on the pattern of medial meniscal tear observed when MOWHTO was performed. In addition, the cartilage grade of MFC before surgery was associated with changes in JSW. The IKDC score was not significantly different between groups. However, a longer follow-up period is needed to analyze the correlation with the meniscal tear pattern and JSW., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI19C1085) and by a 2023 research grant from Pusan National University Yangsan Hospital. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: There is little evidence of the biomechanical performance of medial collateral ligament (MCL) reconstructions for restoring stability to the MCL-deficient knee regarding valgus, external rotation (ER), and anteromedial rotatory instability (AMRI)., Hypothesis: A short isometric reconstruction will better restore stability than a longer superficial MCL (sMCL) reconstruction, and an additional deep MCL (dMCL) graft will better control ER and AMRI than single-strand reconstructions., Study Design: Controlled laboratory study., Methods: Nine cadaveric human knees were tested in a kinematics rig that allowed tibial loading while the knee was flexed-extended 0° to 100°. Optical markers were placed on the femur and tibia and displacements were measured using a stereo camera system. The knee was tested intact, and then after MCL (sMCL + dMCL) transection, and loaded in anterior tibial translation (ATT), ER, varus-valgus, and combined ATT + ER (AMRI loading). Five different isometric MCL reconstructions were tested: isolated long sMCL, a short construct, each with and without dMCL addition, and isolated dMCL reconstruction, using an 8 mm-wide synthetic graft., Results: MCL deficiency caused an increase in ER of 4° at 0° of flexion ( P = .271) up to 14° at 100° of flexion ( P = .002), and valgus laxity increased by 5° to 8° between 0° and 100° of flexion ( P < .024 at 0°-90°). ATT did not increase significantly in isolated MCL deficiency ( P > .999). All 5 reconstructions restored native stability across the arc of flexion apart from the isolated long sMCL, which demonstrated residual ER instability ( P ≤ .047 vs other reconstructions)., Conclusion: All tested techniques apart from the isolated long sMCL graft are satisfactory in the context of restoring the valgus, ER, and AMRI stability to the MCL-deficient knee in a cadaveric model., Clinical Relevance: Contemporary MCL reconstruction techniques fail to control ER and therefore AMRI as they use a long sMCL graft and do not address the dMCL. This study compares 5 MCL reconstruction techniques. Both long and short isometric constructs other than the long sMCL achieved native stability in valgus and ER/AMRI. Double-strand reconstructions (sMCL + dMCL) tended to provide more stability. This study shows which reconstructions demonstrate the best biomechanical performance, informs surgical reconstruction techniques for AMRI, and questions the efficacy of current popular techniques., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This study was funded by a grant from Smith & Nephew paid to a research account of Imperial College London. Human tissue samples were obtained from the MedCure Tissue Bank with approval of the Imperial College Healthcare Tissue Bank supported by the National Institute for Health Research and approved by Wales REC3-17/WA/0161. A.W. is a paid speaker for Smith & Nephew and Director of Fortius Clinic London. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: There is limited evidence related to the effects of autograft type on functional performance after anterior cruciate ligament reconstruction (ACLR)., Purpose/hypothesis: This study aimed to compare biomechanical outcomes during a drop vertical jump (DVJ) between patients with a hamstring tendon (HT) autograft, quadriceps tendon (QT) autograft with bone block, QT autograft without bone block, and bone-patellar tendon-bone autograft at 6 months postoperatively in an adolescent population. The authors' hypothesized there would be differences in DVJ biomechanics between athletes depending on the type of autograft used., Study Design: Controlled laboratory study., Methods: Patients aged 8 to 18 years who underwent primary ACLR were included for analysis. Kinematic and kinetic data collected during a DVJ using a 3-dimensional computerized marker system were assessed at 6 months after ACLR and compared with the uninjured contralateral limb., Results: A total of 155 participants were included. There were no significant differences in terms of age, sex, or affected leg ( P ≥ .1973) between groups. The HT group was significantly associated with a larger knee valgus moment at initial contact compared with the QT group (28 × 10 -2 vs -35 × 10 -2 N·m/kg, respectively; P = .0254) and a significantly larger maximum hip adduction moment compared with the QT with bone block group (30 × 10 -2 vs -4 × 10 -2 N·m/kg, respectively; P = .0426). Both the QT with bone block (-12 × 10 -2 vs -3 × 10 -2 N·m/kg, respectively; P = .0265) and QT (-13 × 10 -2 vs -3 × 10 -2 N·m/kg, respectively; P = .0459) groups demonstrated significantly decreased mean knee extension moments compared with the HT group., Conclusion: The findings of this study suggest that utilizing an HT autograft resulted in a significantly increased knee valgus moment at initial contact compared with a QT autograft without bone block at 6 months after ACLR in adolescent patients performing a DVJ. A QT autograft was found to be associated with significantly decreased extensor mechanism function compared with an HT autograft., Clinical Relevance: This study adds unique kinematic and kinetic information regarding various ACLR autograft options and highlights the biomechanical deficits that should be taken into consideration in rehabilitation., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: S.V.T. has received support for education from ImpactOrtho and hospitality payments from Stryker. J.V. has received support for education from ImpactOrtho and Goode Surgical and hospitality payments from Smith & Nephew. J.C.B. has received support for education from ImpactOrtho and hospitality payments from Stryker. A.C. has received consulting fees from Arthrex and Zimmer Biomet. J.M.T. has received consulting fees from Arthrex, DePuy Synthes, and Medical Device Business Services; royalties from Arthrex; and support for education from ImpactOrtho, Paladin Technology Solutions, Supreme Orthopedic Systems, and Goode Surgical. H.M. has received consulting fees from Medical Device Business Services and support for education from ImpactOrtho and Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Time-dependent postoperative changes in knee joint line obliquity (KJLO) and subsequent adaptational changes in the hip and ankle joints have not been fully proven after medial open wedge high tibial osteotomy (MOWHTO)., Purpose: To investigate the serial postoperative changes in KJLO and subsequent adaptational changes in the hip and ankle joints over time after MOWHTO., Study Design: Case series, Level of evidence, 4., Methods: A total of 92 patients who underwent MOWHTO between April 2015 and December 2020 were evaluated. Radiographic parameters, including KJLO, ankle joint line obliquity (ALO), hip abduction angle (HAA), joint line convergence angle, weightbearing line ratio, and hip-knee-ankle angle, were analyzed in time sequence (preoperatively and 3, 6, 12, and 24 months postoperatively). Repeated-measures analysis of variance and post hoc analysis were used to demonstrate alterations and the statistical significance of KJLO and other related radiographic parameters over time., Results: The mean KJLO values were -1.9°, -2.1°, -2.7°, and -3.2° at 3, 6, 12, and 24 months postoperatively, respectively, indicating that there was consistent increase in valgus tilting of KJLO from 6 to 24 months ( P < .001 for both 6-12 months and 12-24 months). ALO and HAA showed significant changes from 6 to 12 months (ALO, P < .001; HAA, P = .002), but not between 12 and 24 months (ALO: -3.0°, -2.7°, -1.9°, and -1.6°; HAA: -0.8°, -0.9°, -1.5°, and -1.8° at 3, 6, 12, and 24 months, respectively). The mean joint line convergence angle, weightbearing line ratio, and hip-knee-ankle angle did not change significantly from 3 months to 24 months postoperatively., Conclusion: There was a consistent increase in valgus tilting of the postoperative KJLO from 6 to 24 months after MOWHTO. The adaptive ALO and HAA significantly changed between 6 and 12 months and were maintained until 24 months after MOWHTO. It is necessary to consider the adaptive change when hip or ankle surgery is planned within this period., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Osteochondral allograft transplantation (OCAT) is an accepted knee joint-preserving treatment strategy for focal osteochondral lesions that is often conducted in combination with meniscal allograft transplantation (MAT). Despite its frequent and simultaneous utilization, there remains a lack in the literature reporting on outcomes and failure rates after concomitant procedures., Purpose: To determine (1) the midterm clinical success rate after OCAT+MAT in comparison with a matched-pair cohort undergoing isolated OCAT, (2) whether patient-specific and procedural variables influence the risk of failure, and (3) patient-reported outcome measures over time., Study Design: Cohort study; Level of evidence, 3., Methods: A single-center matched-pair cohort study was conducted investigating outcomes in patients who underwent OCAT of the medial or lateral femoral condyle with and without MAT between 2004 and 2020. Patients were matched 1:1 by age (±5 years), sex (male or female), body mass index (±5), and grouped Kellgren and Lawrence grade (grades 0-1 or 2-4). The minimum follow-up time was 2 years. Radiographic variables (International Cartilage Regeneration & Joint Preservation Society [ICRS] grade and Kellgren and Lawrence grade) were assessed preoperatively and at follow-up. Subjective patient-reported outcome measures (Lysholm score, Knee injury and Osteoarthritis Outcome Score [KOOS] including subscores, International Knee Documentation Committee [IKDC] score, and visual analog scale score) were collected preoperatively and at follow-up. Clinical failure was defined as revision surgery for graft failure or conversion to total knee arthroplasty. Patient-reported, clinical, and radiographic outcomes were compared between groups., Results: In total, 66 patients (33 treated with isolated OCAT, 33 treated with OCAT+MAT; 57.6% male) with a mean age of 26.3 years (range, 18-62 years) were followed for a mean of 5.6 years (minimum, 2 years; range, 24-218 months). The 2 cohorts showed no difference in Kellgren and Lawrence grade postoperatively ( P = .59). There was a significantly higher ICRS grade detected at follow-up in the OCAT+MAT group (2.81 ± 1.10) compared with the OCAT group (2.04 ± 0.96) ( P < .05). There were no statistically significant differences between the groups regarding reoperation rate (OCAT: n = 6; OCAT+MAT: n = 13; P = .116), time to reoperation (OCAT: 46.67 ± 47.27 months vs OCAT+MAT: 28.08 ± 30.16 months; P = .061), and failure rate (OCAT: n = 4 [12.1%] vs OCAT+MAT: n = 5 [15.2%]; P = .66). In the OCAT+MAT group, an increase of tibial slope by 1° conferred a 1.65-fold increase in the hazard for failure over decreased slope (hazard ratio, 1.65; 95% CI, 1.10-2.50; P < .05). The overall survival rate was 86% at a mean follow-up of 5.6 years. Patient-reported outcome scores were significantly improved at the final follow-up compared with preoperative status. No significant differences were seen between groups with respect to subjective IKDC, Lysholm, Tegner, and KOOS results, except for the KOOS Symptoms subscale score, which was significantly higher in the OCAT+MAT group than in the OCAT group (mean difference, 14.6; P < .05) and did exceed the minimal clinically important difference threshold of 10.7., Conclusion: Midterm results after isolated OCAT and OCAT+MAT show high rates of healing and sustainable subjective improvement of knee function and quality of life. However, it should be noted that the difference in reoperation rate and time to reoperation between the groups is arguably clinically important and that lack of statistical significance may be because of low power. These results imply that isolated OCAT is an efficient joint-preserving treatment that can be combined with MAT in well-selected patients with meniscal insufficiency without negative influence on global clinical outcomes., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This study was supported by Foderaro-Quattrone Musculoskeletal-Orthopaedic Surgery Research Innovation Fund. M.H. acknowledges research support by the Deutsche Forschungsgemeinschaft (grant No. 466023693). B.A.L. has received royalties and consulting fees from Arthrex; consulting fees from Smith & Nephew; and speaking fees from Linvatec. D.B.F.S. has received consulting fees from Smith & Nephew. M.J.S. has received royalties and consulting fees from Arthrex and research support from Stryker. A.J.K. has received research support from Aesculap/B.Braun, Arthrex, Arthritis Foundation, Ceterix, and Histogenics; consulting fees from Arthrex, JRF Ortho, Vericel, and Responsive Arthroscopy; royalties from Arthrex and Responsive Arthroscopy; honoraria from Joint Restoration Foundation, Vericel, and Musculoskeletal Transplant Foundation; a grant from DJO; and hospitality payments from Ceterix Orthopaedic, Gemini Mountain Medical, and Smith & Nephew. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Anteromedial rotatory instability (AMRI) of the knee is a complex and severe condition caused by injury to the anterior cruciate ligament and/or the medial collateral ligament. Clinical studies dealing with AMRI are rare, and objective measurements are nonexistent., Purpose/hypothesis: The objectives of this study were, first, to quantify anteromedial rotatory knee laxity in healthy individuals using a noninvasive image analysis software and, second, to assess intra- and interrater reliability and equivalence in measuring anteromedial knee translation (AMT). It was hypothesized that AMT could be reliably quantified using a noninvasive image analysis software., Study Design: Cohort study; Level of evidence, 3., Methods: This prospective proof-of-concept study included healthy individuals aged 16 to 40 years with no history of knee injury or surgery. Three adhesive surface markers were placed on predefined landmarks on the medial side of the knee. Three independent investigators examined anteromedial rotatory knee laxity with an anterior drawer test in different tibial rotations (neutral tibial rotation, 15° of external tibial rotation, and 15° of internal tibial rotation). The entire examination of each knee was recorded, and AMT including the side-to-side difference (SSD) was assessed using a freely available and validated image analysis software (PIVOT iPad application). Group comparisons were performed using a 1-way analysis of variance with Bonferroni-adjusted post hoc analysis. Intraclass correlation coefficients (ICCs) were calculated to assess inter- and intrarater reliability of AMT measurements. Equivalence of measurements was evaluated using the 2 one-sided t -test procedure., Results: Anteromedial rotatory knee laxity was assessed in 30 knees of 15 participants (53% male) with a mean age of 26.2 ± 3.5 years. In all 3 raters, the highest AMT was observed in neutral tibial rotation (range of means, 2.2-3.0 mm), followed by external tibial rotation (range of means, 2.0-2.4 mm) and internal tibial rotation (range of means, 1.8-2.2 mm; P < .05). Intrarater reliability of AMT (ICC, 0.88-0.96) and SSD (ICC, 0.61-0.96) measurements was good to excellent and moderate to excellent, respectively. However, interrater reliability was poor to moderate for AMT (ICC, 0.44-0.73) and SSD (ICC, 0.12-0.69) measurements. Statistically significant equivalence of AMT and SSD measurements was observed between and within raters for almost all testing conditions., Conclusion: Anteromedial rotatory knee laxity could be quantified using a noninvasive image analysis software, with the highest AMT observed during neutral tibial rotation in uninjured individuals. Reliability and equivalence of measurements were good to excellent within raters and moderate between raters., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: S.S. has received consulting fees from Arthrex GmbH, KLS Martin Group, Medartios AG, and medi GmnH. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: There is ongoing debate about the best way to manage ramp lesions at the time of anterior cruciate ligament (ACL) reconstruction (ACLR). Type 3 lesions are not visible by the transnotch approach without superior debridement, making the management debate even more problematic., Purpose/hypothesis: The purpose of this study was to evaluate the rate of secondary surgical interventions according to the management method of a type 3 ramp lesion concomitant with primary ACLR. The hypothesis was that the rate of secondary ACL or meniscal interventions would be higher in patients who underwent all-inside repair., Study Design: Cohort study; Level of evidence, 3., Methods: A retrospective analysis of all patients who underwent primary ACLR with a type 3 ramp lesion between January 2012 and May 2020, regardless of the treatment method, was performed. The main criterion analyzed in this cohort was a secondary surgical intervention, defined as revision ACLR or a reintervention of the repaired meniscus. A survivorship analysis was performed to evaluate secondary surgical interventions in 3 groups: all-inside repair, suture hook repair, and left in situ. The following data were collected preoperatively and at the last follow-up: patient characteristics, time to surgery, side-to-side difference in laxity, pivot shift, Lysholm score, subjective International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, Tegner score, and meniscal repair failure rate., Results: A total of 113 patients who underwent type 3 ramp lesion repair concomitant with ACLR were included: 52 (46.0%) in the all-inside repair group, 23 (20.4%) in the suture hook repair group, and 38 (33.6%) in the lesion left in situ group. There were 17 patients (15.0%) who underwent a secondary intervention because of ACL graft failure (n = 6) or meniscal repair failure (n = 15 [4 of whom underwent a concomitant ACL reintervention]). Overall, 62 patients (54.9%) underwent combined ACLR and anterolateral ligament reconstruction, while 51 patients (45.1%) underwent isolated ACLR. In the adjusted Cox model, the type of meniscal repair was not statistically significantly associated with secondary surgical interventions. The only risk factor for secondary surgical interventions in this cohort was isolated ACLR (hazard ratio, 8.077; P = .007)., Conclusion: The rates of secondary surgical interventions after medial meniscal type 3 ramp lesion repair concomitant with ACLR were similar regardless of the management method of the meniscal lesion. Despite not being associated with meniscal treatment, this rate was 8 times higher for patients who underwent isolated ACLR in this cohort; this is probably because of the protection that lateral extra-articular procedures provide to the ACL graft., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: J.-M.F. is a consultant for Arthrex and Newclip Technics. M.T. is a consultant for Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Primary repair of the anterior cruciate ligament (ACL) has some potential advantages over the reconstruction technique, which include but are not limited to better knee sensation due to preservation of the natural ACL tissue in patients compared with tendon graft. Proprioception is impaired after ACL injuries and the sense of the joint position is lost., Purpose/hypothesis: The purpose of this study was to compare arthroscopic ACL primary repair and ACL reconstruction techniques clinically and functionally and analyze the differences in proprioception. It was hypothesized that primary repair would restore knee joint proprioception more successfully because the original tissue of the ACL is preserved., Study Design: Cohort study; Level of evidence, 3., Methods: A total of 63 patients (34 underwent reconstruction and 29 underwent primary repair between 2017 and 2020) and 33 healthy controls, as well as the healthy knees of the operated groups, were evaluated between 24 and 48 months (mean, 29 months) postoperatively. Patients with proximal femoral avulsion tears and stump quality suitable for repair underwent primary repair, and those with tears outside these criteria underwent reconstruction using hamstring tendon autograft. Proprioception was evaluated using the active joint position sensation method during weightbearing, with a digital inclinometer used to measure differences between the target and achieved flexion angles of 15°, 30°, and 60°., Results: At 15° of knee flexion, the deviation angles for the healthy knee of the reconstruction and primary repair groups were significantly smaller than those of the control group ( P < .001), but there was no statistically significant difference between the groups in terms of deviation angle at 30° and 60° of flexion. The deviation angle of the operated knees was statistically significantly larger in the reconstruction group than in the primary repair group at all angles. The deviation angles at 15°, 30°, and 60° were 2.83°, 2.66°, and 2.66° in the reconstruction group and 1.00°, 1.00°, and 1.33° in the primary repair group, respectively ( P < .001). There was no statistically significant difference between the reconstruction and primary repair groups in terms of clinical scores., Conclusion: Primary ACL repair can preserve proprioception in a well-selected patient group. In short-term follow-up, primary repair of the ACL in patients with proximal femoral avulsion tears and stump quality suitable for repair appears to be proprioceptively protective. Future studies are needed to clarify the long-term consequences of primary repair on proprioception in a larger population., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: There is a higher rate of failure of isolated MPFL reconstruction in skeletally immature patients with patellar instability compared to skeletally mature patients. Genu valgum is a known risk factor for patellar instability. There is potential for concomitant surgical correction of genu valgum to achieve better clinical outcomes and to decrease failure rates of MPFL reconstruction., Purpose: To evaluate outcomes of combined medial patellofemoral ligament (MPFL) reconstruction and implant-mediated guided growth (IMGG) in skeletally immature patients with patellar instability and genu valgum., Study Design: Case series; Level of evidence, 4., Methods: In a multicenter study, all skeletally immature patients with recurrent patellar instability and genu valgum who underwent MPFL reconstruction using hamstring graft and IMGG using a transphyseal screw or tension band plate for the distal femur and/or proximal tibia were included. The knee valgus angle and mechanical axis were measured on full-length radiographs and anatomic risk factors were measured on MRI. Patients were followed until correction of their lower limb alignment and implant removal or until skeletal maturity. Clinical outcomes, including complications, were analyzed., Results: A total of 31 patients (37 knees) were included in the study. The mean age and skeletal age of the cohort were 12.4 and 12.9 years, respectively. Simultaneous MPFL reconstruction and IMGG were performed in 26 of 37 knees; 11 underwent staged procedures. Twenty knees had transphyseal screws and 17 knees had tension band plates for IMGG. The knee valgus corrected from a mean of 12.4° to 5.1° in 12.1 months. Implants were removed from 22 of 37 knees once genu valgum was corrected. There was no significant difference ( P = .65) in the correction rate between plates (0.7 deg/month) and screws (0.6 deg/month). Ten complications occurred in 4 patients (7 knees) and included 5 patellar redislocations, 2 rebound valgus, 1 varus overcorrection, 1 knee arthrofibrosis, and 1 implant loosening. For children <10 years of age, 3 of 6 (50%) knees had patellar redislocations and 5 of 6 knees had a complication. This was statistically significant ( P = .003) compared with patients >10 years of age. Similarly, for patients with bilateral knee involvement, 5 of 12 (42%) knees had patellar redislocations and a total of 8 complications occurred in this subset. This was statistically significant ( P < .001) compared with patients with unilateral involvement., Conclusion: IMGG with plates or screws in the setting of combined MPFL reconstruction improves genu valgum. Children <10 years of age and those with bilateral instability with genu valgum remain difficult subsets to treat with higher complication rates., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: D.B. has received support for education from Arthrex and Legacy Ortho. D.P. has received support for education from SeaPearl Inc and Liberty Surgical. E.J.W. has received support for education from Legacy Ortho. M.E. has received support for education from MedInc of Texas and Arthrex. N.F. has received support for education from Arthrex and Sequoia Surgical and compensation for services other than consulting from Arthrex. J.A.S. has received support for education from Arthrex and Micromed and compensation for services other than consulting from Arthrex. D.G. has received consulting fees from OrthoPediatrics and Arthrex, royalties from Arthrex, and compensation for serving as a faculty or speaker from Synthes GmbH. S.N.P. has received consulting fees from Pfizer, support for education from CDC Medical, and compensation for serving as a faculty or speaker from Synthes GmbH. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Concerns have arisen that anterior cruciate ligament reconstruction (ACLR) with lateral extra-articular tenodesis (LET) may accelerate the development of posttraumatic osteoarthritis in the lateral compartment of the knee., Purpose/hypothesis: The purpose of this study was to evaluate whether the augmentation of ACLR with LET affects the quality of lateral compartment articular cartilage on magnetic resonance imaging (MRI) at 2 years postoperatively. We hypothesized that there would be no difference in T1rho and T2 relaxation times when comparing ACLR alone with ACLR + LET., Study Design: Randomized controlled trial; Level of evidence, 1., Methods: A consecutive subgroup of patients at the Fowler Kennedy Sport Medicine Clinic participating in the STABILITY 1 Study underwent bilateral 3-T MRI at 2 years after surgery. The primary outcome was T1rho and T2 relaxation times. Articular cartilage in the lateral compartment was manually segmented into 3 regions of the tibia (lateral tibia [LT]-1 to LT-3) and 5 regions of the femur (lateral femoral condyle [LFC]-1 to LFC-5). Analysis of covariance was used to compare relaxation times between groups, adjusted for lateral meniscal tears and treatment, cartilage and bone marrow lesions, contralateral relaxation times, and time since surgery. Semiquantitative MRI scores according to the Anterior Cruciate Ligament OsteoArthritis Score were compared between groups. Correlations were used to determine the association between secondary outcomes (including results of the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, Lower Extremity Functional Scale, 4-Item Pain Intensity Measure, hop tests, and isokinetic quadriceps and hamstring strength tests) and cartilage relaxation., Results: A total of 95 participants (44 ACLR alone, 51 ACLR + LET) with a mean age of 18.8 years (61.1% female [58/95]) underwent 2-year MRI (range, 20-36 months). T1rho relaxation times were significantly elevated for the ACLR + LET group in LT-1 (37.3 ± 0.7 ms vs 34.1 ± 0.8 ms, respectively; P = .005) and LFC-2 (43.9 ± 0.9 ms vs 40.2 ± 1.0 ms, respectively; P = .008) compared with the ACLR alone group. T2 relaxation times were significantly elevated for the ACLR + LET group in LFC-1 (51.2 ± 0.7 ms vs 49.1 ± 0.7 ms, respectively; P = .03) and LFC-4 (45.9 ± 0.5 ms vs 44.2 ± 0.6 ms, respectively; P = .04) compared with the ACLR alone group. All effect sizes were small to medium. There was no difference in Anterior Cruciate Ligament OsteoArthritis Scores between groups ( P = .99). Weak negative associations ( r s = -0.27 to -0.22; P < .05) were found between relaxation times and quadriceps and hamstring strength in the anterolateral knee, while all other correlations were nonsignificant ( P > .05)., Conclusion: Increased relaxation times demonstrating small to medium effect sizes suggested early biochemical changes in articular cartilage of the anterolateral compartment in the ACLR + LET group compared with the ACLR alone group. Further evidence and long-term follow-up are needed to better understand the association between these results and the potential risk of the development of osteoarthritis in our patient cohort., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A.M.J.G. reports grants from the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine during the conduct of this study. He also reports grants, personal fees, and nonfinancial support from Smith & Nephew; grants from Ossur; personal fees and stocks from PrecisionOS; stocks from LinkX; and stocks from Spring Loaded Technology. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Adjusting the direction of the anterolateral ligament (ALL) femoral tunnel is suggested to avoid tunnel convergence during anterior cruciate ligament (ACL) reconstruction. Yet, there has been no in vivo clinical study reporting the effect of changing the direction of the ALL tunnel on the incidence of convergence with the ACL tunnel., Purpose: To report the incidence of convergence between the ACL femoral tunnel and a distally and anteriorly directed ALL femoral tunnel and to determine a safe distal angle and anterior angle., Study Design: Cross-sectional study; Level of evidence, 3., Methods: A total of 227 patients undergoing concomitant ALL and anatomic single-bundle ACL reconstruction between January 2020 and December 2022 were retrospectively reviewed. The tunnel convergence rate, angular orientation of the tunnels, and distance between tunnels were obtained using postoperative computed tomography. The patients were grouped based on the direction of the ALL tunnel (transverse vs distal anterior) and the presence of tunnel convergence (convergence vs no convergence)., Results: The overall tunnel convergence rate was 53.3% (121/227 patients). Tunnel convergence was observed less frequently in the distal anterior group (33.7%) than in the transverse group (65.2%) ( P < .001). The no convergence group showed an ALL tunnel oriented more distally (20.2°± 11.1°) and anteriorly (19.5°± 10.2°) compared with the convergence group (8.7°± 6.5° and 6.9°± 5.3°, respectively) ( P = .005 and P = .008, respectively). There were no cases of tunnel convergence for ALL tunnels >24.3° distally and >25.5° anteriorly. There was no difference in the angle of the ACL femoral tunnel between all groups., Conclusion: A distally and anteriorly directed ALL femoral tunnel reduced the incidence of convergence with the ACL femoral tunnel. A distal angle >24.3° and an anterior angle >25.5° of an ALL tunnel are suggested to safely avoid convergence with the ACL tunnel., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This work was supported by grants from the Korea Medical Device Development Fund (funded by the Ministry of Science and ICT; the Ministry of Trade, Industry and Energy; the Ministry of Health and Welfare; and the Ministry of Food and Drug Safety) (project No. 1415181807, RS-2021-KD000001, and RS-2020-KD000297). AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Long-term outcomes in larger cohorts after matrix-induced autologous chondrocyte implantation (MACI) are required. Furthermore, little is known about the longer-term clinical and radiological outcomes of MACI performed in the tibiofemoral versus patellofemoral knee joint., Purpose: To present the 10-year clinical and radiological outcomes in patients after MACI and compare outcomes in patients undergoing tibiofemoral versus patellofemoral MACI., Study Design: Case series; Level of evidence, 4., Methods: Between September 2002 and December 2012, 204 patients who underwent MACI were prospectively registered into a research program and assessed preoperatively and at 2, 5, and 10 years postoperatively. Of these patients, 168 were available for clinical review at 10 years, with 151 (of a total of 182) grafts also assessed via magnetic resonance imaging (MRI). Patients were evaluated using the Knee injury and Osteoarthritis Outcome Score, a visual analog scale for pain frequency and severity, satisfaction, and peak isokinetic knee extensor and flexor strength. Limb symmetry indices (LSIs) were calculated for strength measures. Grafts were scored on MRI scans via the MOCART (magnetic resonance observation of cartilage repair tissue) system, with a focus on tissue infill and an overall MRI graft composite score., Results: All patient-reported outcome measures improved ( P < .0001) up to 2 years after surgery. Apart from the significant increase ( P = .004) in the peak isokinetic knee extensor LSI, no other patient-reported outcome measure or clinical score had changed significantly from 2 to 10 years. At the final follow-up, 92% of patients were satisfied with MACI to provide knee pain relief, with 76% satisfied with their ability to participate in sports. From 2 to 10 years, no significant change was seen for any MRI-based MOCART variable nor the overall MRI composite score. Of the 151 grafts reviewed via MRI at 10 years, 14 (9.3%) had failed, defined by graft delamination or no graft tissue on MRI scan. Furthermore, of the 36 patients (of the prospectively recruited 204) who were not available for longer-term review, 7 had already proceeded to total knee arthroplasty, and 1 patient had undergone secondary MACI at the same medial femoral condylar site because of an earlier graft failure. Therefore, 22 patients (10.8%) essentially had graft failure over the period. At the final follow-up, patients who underwent MACI in the tibiofemoral (vs patellofemoral) joint reported significantly better Knee injury and Osteoarthritis Outcome Score subscale scores for Quality of Life ( P = .010) and Sport and Recreation ( P < .001), as well as a greater knee extensor strength LSI ( P = .002). Even though the tibiofemoral group demonstrated better 10-year MOCART scores for tissue infill ( P = .027), there were no other MRI-based differences ( P > .05)., Conclusion: This study reports the long-term review of a prospective series of patients undergoing MACI, demonstrating good clinical scores, high levels of patient satisfaction, and acceptable graft survivorship at 10 years. Patients undergoing tibiofemoral (vs patellofemoral) MACI reported better long-term clinical outcomes, despite largely similar MRI-based outcomes., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This research has received some funding from the National Health and Medical Research Council (ID254622 and ID1003452) and the Hollywood Private Hospital Research Foundation (RF31 and RF050). This research was approved by the Hollywood Private Hospital (HPH145) Human Research Ethics Committee. J.R.E. has received support for education and research support from Vericel. G.C.J. has shares in Orthocell. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Conflicting evidence has been reported regarding the biomechanical relevance of ramp lesions (RLs) on knee kinematics. Furthermore, the influence of the defect size of the RLs on anterior tibial translation (ATT) and external rotation (ER) is currently unknown., Purpose: To evaluate the influence of RL defect size on knee kinematics in anterior cruciate ligament (ACL) deficiency and after simulated ACL reconstruction (sACLR)., Study Design: Controlled laboratory study., Methods: Eight cadaveric knee specimens were tested in a 6 degrees of freedom robotic test setup. Force-controlled clinical laxity tests were performed with 200 N of axial compression in 0°, 30°, 60°, and 90° of flexion: 5 N·m internal rotation (IR)/ER torque, 134 N ATT force, and an anteromedial drawer test consisting of 134 N ATT force under 5 N·m ER torque. After determining the native knee kinematics, the ACL was cut at the tibial insertion, followed by a transosseous refixation to simulate a surgical repair or reconstruction (simulated ACL reconstruction; sACLR). An RL was sequentially created with a length of 1, 2, and 3 cm. Each state of the RL was evaluated in the ACL-deficient state and after sACLR., Results: In the ACL-deficient state, only an RL of 3 cm length resulted in a significant increase of ATT in 30° of flexion (mean difference 0.73 mm; 95% CI, 0.36-1.1 mm). After sACLR, an RL had no significant effect. When looking at ER, an RL significantly increased ER in full extension in the ACL-deficient state in 2 cm (mean difference 0.9°; 95% CI, 0.08°-1.74°) and 3 cm length (mean difference 1.9°; 95% CI, 0.57-3.25). Furthermore, a 3-cm RL significantly increased IR in 0° of flexion in the ACL-deficient state (mean difference 1.9°; 95% CI, 0.2°-3.6°). No effect of ramp lesions on rotation was found after sACLR., Conclusion: RLs result in a small increase in ATT, ER, and IR in ACL-deficient knees at early flexion angles, but not after sACLR., Clinical Relevance: Small RLs did not change time-zero knee kinematics and may, therefore, be left untreated, especially when the ACL is reconstructed., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: Funding was received from the Society for Arthroscopy and Joint Surgery (AGA) through the AGA-medi-Award 2023. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Historical MCL (medial collateral ligament) reconstruction (MCLR) techniques have focused on the superficial MCL (sMCL) to restore valgus stability while frequently ignoring the importance of the deep MCL (dMCL) in controlling tibial external rotation. The recent recognition of the medial ligament complex importance has multiple studies revisiting medial anatomy and questioning contemporary MCLR techniques., Purpose: To assess whether (1) an isolated sMCL reconstruction (sMCLR), (2) an isolated dMCL reconstruction (dMCLR), or (3) a novel single-strand short isometric construct (SIC) would restore translational and rotational stability to a knee with a dMCL and sMCL injury., Study Design: Controlled laboratory study., Methods: Biomechanical testing was performed on 14 fresh-frozen cadaveric knee specimens using a custom multiaxial knee activity simulator. The specimens were divided into 2 groups. The first group was tested in 4 states: intact, after sectioning the sMCL and dMCL, isolated sMCLR, and isolated dMCLR. The second group was tested in 3 states: intact, after sectioning the sMCL and dMCL, and after single-strand SIC reconstruction (SICR). In each state, 4 loading conditions were applied at 0°, 20°, 40°, 60°, and 90° of knee flexion: 8-N·m valgus torque, 5-N·m external rotation torque, 90-N anterior drawer, and combined 90-N anterior drawer plus 5-N·m tibial external rotation torque. Anterior translation, valgus rotation, and external rotation of the knee were measured for each state and loading condition using an optical motion capture system., Results: sMCL and dMCL transection resulted in increased laxity for all loading conditions at all flexion angles. Isolated dMCLR restored external rotation stability to intact levels throughout all degrees of flexion, yet valgus stability was restored only at 0° of flexion. Isolated sMCLR restored valgus and external rotation stability at 0°, 20°, and 40° of flexion but not at 60° or 90° of flexion. Single-strand SICR restored valgus and external rotation stability at all flexion angles. In the combined anterior drawer plus external rotation test, isolated dMCL and single-strand SICR restored stability to the intact level at all flexion angles, while the isolated sMCL restored stability at 20° and 40° of flexion but not at 60° or 90° of flexion., Conclusion: In the cadaveric model, single-strand SICR restored valgus and rotational stability throughout the range of motion. dMCLR restored rotational stability to the knee throughout the range of motion but did not restore valgus stability. Isolated sMCLR restored external rotation and valgus stability in early flexion., Clinical Relevance: In patients with anteromedial rotatory instability in the knee, neither an sMCLR nor a dMCLR is sufficient to restore stability., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: K.A.B. has received consulting fees from Xiros Inc and DePuy Synthes; speaking fees from Arthrex Inc; support for education from MedInc of Texas; and hospitality payments from Medical Device Business Services. A.W. has received part of the funding of a clinical fellowship/research funding from Smith & Nephew and holds stock in DocComs and Innovate. W.R.L. has received consulting fees, paid presenter or speaker fees, and travel reimbursement to meetings from MedInc of Texas; royalty, license, and consulting fees from Arthrex; hospitality payments at various meetings from Linvatec Corp, Biorez Inc, Arthrex Inc, Alafair Biosciences, and MedInc of Texas. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: An anterior cruciate ligament (ACL) injury accompanied by patellar instability (PI) is a topic that has gained orthopaedic surgeons' attention recently. Untreated PI is reportedly associated with worse clinical outcomes after isolated ACL reconstruction (ACLR) in patients after an ACL injury with PI. Nevertheless, the appropriate surgical approach and its long-term therapeutic effects in these patients remain unclear., Purpose: (1) To compare the clinical and radiological outcomes between isolated ACLR (iACLR) and combined ACLR and medial patellofemoral ligament reconstruction (cAMR) in patients after an ACL injury with PI and (2) to explore the correlations between these 2 procedures and clinical and radiological outcomes., Study Design: Cohort study; Level of evidence, 3., Methods: A total of 106 patients diagnosed with an ACL injury accompanied by PI between January 2016 and April 2021 were analyzed in this study. There were 34 patients excluded because of missing postoperative radiological data. Among the remaining 72 patients, 34 patients underwent iACLR, while 38 patients underwent cAMR. Demographic characteristics, intraoperative findings, and patient-reported outcomes (Lysholm score, subjective International Knee Documentation Committee score, and Tegner activity score) were prospectively collected. Patellar alignment parameters and worsening patellofemoral osteoarthritis (PFOA) features (evaluated with the modified Whole-Organ Magnetic Resonance Imaging Score) were analyzed longitudinally on magnetic resonance imaging. The Kujala score was used to evaluate the functional recovery of the patellofemoral joint, and redislocations of the patella were prospectively recorded. Finally, multivariate logistic regression analysis was used to explore the correlations between these 2 procedures and clinical (not achieving the minimal detectable change [MDC] for the Lysholm score) and radiological (worsening PFOA features) outcomes., Results: The mean follow-up duration was 28.9 ± 6.2 and 27.1 ± 6.8 months for the iACLR and cAMR groups, respectively ( P = .231). Significantly higher Lysholm scores (88.3 ± 9.9 vs 82.1 ± 11.1, respectively; P = .016) and subjective International Knee Documentation Committee scores (83.6 ± 11.9 vs 78.3 ± 10.2, respectively; P = .046) were detected in the cAMR group compared with the iACLR group postoperatively. The rates of return to preinjury sports were 20.6% and 44.7% in the iACLR and cAMR groups, respectively (difference, 24.1% [95% CI, 3.3%-45.0%]; P = .030). Moreover, the rates of worsening PFOA features were 44.1% and 18.4% in the iACLR and cAMR groups, respectively (difference, 25.7% [95% CI, 4.9%-46.4%]; P = .018). In addition, significantly higher Kujala scores (87.9 ± 11.3 vs 80.1 ± 12.0, respectively; P = .006), lower redislocation rates (0.0% vs 11.8%, respectively; difference, 11.8% [95% CI, 0.9%-22.6%]; P = .045), and significantly better patellar alignment were detected in the cAMR group compared with the iACLR group postoperatively. Furthermore, multivariate logistic regression analysis determined that iACLR and partial lateral meniscectomy were significantly correlated with not achieving the MDC for the Lysholm score and worsening PFOA features in our study population., Conclusion: In patients after an ACL injury with PI, cAMR yielded better clinical and radiological outcomes compared with iACLR, with better patellar stability and a lower proportion of worsening PFOA features. Furthermore, not achieving the MDC for the Lysholm score and worsening PFOA features were significantly correlated with iACLR and partial lateral meniscectomy. Our study suggests that cAMR may be a more appropriate procedure for patients after an ACL injury with PI, which warrants further high-level clinical evidence., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This work was supported by the National Natural Science Foundation of China (31370945, 82002274, 82272579), Natural Science Foundation of Shanghai (19ZR1438500), Shanghai Rising-Star Program (21QC1401300), and Shanghai Science and Technology Committee (22dz1204700). AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Previous research has found that the incidence of neurovascular injury is greatest among multiligamentous knee injuries (MLKIs) with documented knee dislocation (KD). However, it is unknown whether there is a comparative difference in functional recovery based on evidence of a true dislocation., Purpose: To determine whether the knee dislocation-3 (KD3) injury pattern of MLKI with documented tibiofemoral dislocation represents a more severe injury than KD3 MLKI without documented dislocation, as manifested by poorer clinical outcomes at long-term follow-up., Study Design: Cohort study; Level of evidence, 3., Methods: A multicenter retrospective cohort study was performed of patients who underwent surgical treatment for KD3 MLKI between May 2012 and February 2021. Outcomes were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner activity scale, and visual analog scale (VAS) for pain. Documented dislocation was defined as a radiographically confirmed tibiofemoral disarticulation, the equivalent radiology report from outside transfer, or emergency department documentation of a knee reduction maneuver. Subgroup analysis was performed comparing lateral (KD3-L) versus medial (KD3-M) injuries. Multivariable linear regression was conducted to determine whether documented dislocation was predictive of outcomes., Results: A total of 42 patients (25 male, 17 female) were assessed at a mean 6.5-year follow-up (range, 2.1-10.7 years). Twenty patients (47.6%) were found to have a documented KD; they reported significantly lower IKDC (49.9 vs 63.0; P = .043), Lysholm (59.8 vs 74.5; P = .023), and Tegner activity level (2.9 vs 4.7; P = .027) scores than the patients without documented dislocation. VAS pain was not significantly different between groups (36.4 vs 33.5; P = .269). The incidence of neurovascular injury was greater among those with documented dislocation (45.0% vs 13.6%; P = .040). Subgroup analysis found that patients with KD3-L injuries experienced a greater deficit in Tegner activity level than patients with KD3-M injuries (Δ: -3.4 vs -1.2; P = .006) and had an increased incidence of neurovascular injury (41.7% vs 11.1%; P = .042). Documented dislocation status was predictive of poorer IKDC (β = -2.15; P = .038) and Lysholm (β = -2.85; P = .007) scores., Conclusion: Patients undergoing surgical management of KD3 injuries with true, documented KD had significantly worse clinical and functional outcomes than those with nondislocated joints at a mean 6.5-year follow-up. The current MLKI classification based solely on ligament involvement may be obscuring outcome research by not accounting for true dislocation., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: L.M.J. has received research support from Arthrex, Mitek, and Smith & Nephew; and support for education from Suvon Surgical, Gotham Surgical, Arthrex, and Flexion Therapeutics; L.M.J. also holds stocks or stock options in Lazurite. M.J.M. has received consulting fees from Smith & Nephew. M.J.A. has received consulting fees from BodyCad, JRF Ortho, Mitek, and DePuy Synthes; research support from Orcosa; and support for education from Gotham Surgical Solutions and Suvon Surgical. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Despite the well-established role of lateral extra-articular procedures (LEAPs) in reducing failure rates after anterior cruciate ligament (ACL) reconstruction (ACLR) in the adult population, similar in-depth research for the adolescent and pediatric population remains lacking., Purpose: To examine the effect of the LEAP augmentation on the rerupture rate after ACLR in patients aged <18 years., Study Design: Cohort study; Level of evidence, 3., Methods: This was a retrospective analysis of prospectively collected data from October 2012 to June 2020, involving adolescents <18 years old undergoing primary ACLR with a minimum follow-up of 2 years. Two groups, matched for age, sex, Tegner activity scale, and presence of meniscal injury, were established: ACLR alone and ACLR+LEAP augmentation. The primary outcome measure was the rate of rerupture after ACLR. The secondary outcome measures were the rate of non-graft rupture related reoperation after ACLR; rate of return to sport (RTS) rate, timing, and level compared with preinjury status; and functional scores including the International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS) (Pain, Symptoms, Activities of Daily Living, Sport and Recreation, and Quality of Life), Tegner activity scale score, ACL Return to Sport after Injury (ACL-RSI) score, and Lysholm score., Results: After accounting for follow-up losses, we analyzed 132 patients who underwent ACLR alone and 121 patients who underwent ACLR+LEAP from the initial 147 per group. The mean age of the patients in both groups was 16.1 years (SD, 1.1 and 1.0 years, respectively), with similar patient and injury characteristics across both groups ( P > .05). Both groups also showed comparable preoperative functional scores. A significantly lower preoperative ACL-RSI score was observed in the ACLR-alone group compared with the ACLR+LEAP group ( P = .0044). Graft rupture was significantly less common in the ACLR+LEAP group (2.5%) than in the ACLR-alone group (13.6%) ( P = .002). The attributable risk reduction for ACLR+LEAP was 11.1%, and the calculated number needed to treat was 9. Kaplan-Meier analysis showed significantly better rerupture-free survival at 5 years for the ACLR+LEAP group ( P = .001). Cox regression confirmed a 6-fold increased rerupture risk in the ACLR-alone group ( P = .004). At the final follow-up, despite similar IKDC, KOOS, Lysholm, and ACL-RSI values across both groups, the ACLR+LEAP group had a significantly higher Tegner score (7.2 vs 6.3; P = .0042). No significant differences were observed in RTS rates or sport level compared with preinjury states between the groups., Conclusion: ACLR+LEAP augmentation significantly reduced rerupture risk and facilitated higher postoperative activity levels in adolescents., Registration: NCT02511158 (ClinicalTrials.gov identifier)., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: N.L. has received consulting fees from Websurvey Society. A.H. has received consulting fees from Arthrex and DePuy. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Open reduction and internal fixation (ORIF) has been widely performed because the osteochondral component of the osteochondritis dissecans (OCD) lesion is the most suitable for reconstructing the joint structure., Purpose: To evaluate radiological healing in terms of reconstructed bony structure after ORIF with bone graft by computed tomography (CT), to identify preoperative prognostic factors for failure, and to determine the cutoff value of radiological healing for risk of failure., Study Design: Case-control study; Level of evidence, 3., Methods: A retrospective cohort study of 42 patients (44 knees) who underwent internal fixation with bone graft for OCD lesions of the knee from 2004 to 2018 was conducted. All patients were evaluated 6 months postoperatively, and if not healed 6 months after surgery, they were evaluated by CT periodically thereafter. Radiological healing was judged according to the following 3 criteria: (1) reossification of the OCD lesion, (2) bony continuity between the OCD lesion and basal floor, and (3) reconstructed bony surface of the femoral condyle reconstructed to match the normal joint. Then, the percentage of the radiological healing area was calculated as the ratio of the healing length to the total lesion length. The nonhealing area was calculated by multiplying the sum of the total nonhealing length. Clinical failure was defined as any definitive reoperation for the same OCD lesion, such as fragment excision, or a cartilage restoration procedure. After 6 months, all eligible patients underwent arthroscopy to check for protrusion of the absorbable pin into the joint; the removal of an absorbable pin protruding into the joint was not considered a failure., Results: Clinical failure was recorded for 4 cases (9.1%). The mean overall percentage of the radiological healing area of OCD 6 months after ORIF with bone graft was 79.5% ± 24.4%, and the mean overall nonhealing area at 6 months was 87.8 ± 107.9 mm 2 . The percentages of radiological healing area of stable (International Cartilage Regeneration & Joint Preservation Society OCD II) lesions and femoral condylar (lateral femoral condyle + medial femoral condyle) lesions were significantly lower than unstable lesions and femoral groove lesions, respectively ( P = .01 and P = .03, respectively). On receiver operating characteristic curve analysis, the cutoff points for predicting a significantly increased risk of failure were 33.9% (sensitivity, 100%; specificity, 100%; area under the curve, 1) for the percentage of radiological healing area and 222.9 mm 2 (sensitivity, 95%; specificity, 100%; area under the curve, 0.956) for the nonhealing area 6 months postoperatively., Conclusion: A stable lesion and a femoral condylar lesion were the predictors of poor radiological healing on CT images 6 months after ORIF with bone graft. The risk of failure was increased significantly in cases with only approximately one-third of the lesion healed or in cases with large nonhealing areas at 6 months postoperatively., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Costal chondrocyte-derived pellet-type autologous chondrocyte implantation (CCP-ACI) has been introduced as a new therapeutic option for the treatment of articular cartilage defects. We had previously conducted a randomized controlled trial comparing CCP-ACI versus microfracture at 1 year postoperatively., Purpose: To compare the efficacy and safety of CCP-ACI versus microfracture for the treatment of articular cartilage defects of the knee at 5 years postoperatively., Study Design: Randomized controlled trial; Level of evidence, 2., Methods: This study describes the mean 5-year follow-up of a previously published prospective clinical trial. The previous prospective trial compared the results of CCP-ACI versus microfracture until 1 year of follow-up. Of the 30 patients who were included in the previous study, 25 were followed up for 5 years. Patients were evaluated based on clinical outcome scores (Lysholm score, International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score [KOOS], and visual analog scale for pain), magnetic resonance imaging findings, and rates of treatment failure at last follow-up., Results: The MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score in the CCP-ACI group was significantly higher than that in the microfracture group at 5 years (62.3 vs 26.7, respectively; P < .0001). The Lysholm score and KOOS score in the CCP-ACI group were significantly higher than those in the microfracture group at 5 years (84.5 vs 64.9, respectively, and 390.9 vs 303.0, respectively; P = .023 and P = .017, respectively). There was 1 case of treatment failure that occurred in the microfracture group., Conclusion: The present randomized controlled trial indicated that the results of both procedures clinically and statistically significantly improved at 1 and 5 years' follow-up in treating cartilage defects, but the results of CCP-ACI were superior to those of microfracture. Magnetic resonance imaging conducted at 1 year and 5 years after CCP-ACI revealed statistically significant superior structural integration with native cartilage tissue compared with microfracture., Registration: NCT03545269 (ClinicalTrials.gov)., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This work was supported by grants from the Ministry of Health and Welfare, Republic of Korea (HI15C0963, HI20C0067). This work was also supported by the National Research Foundation of Korea grant funded by the Ministry of Science and ICT, Republic of Korea (No. RS-2023-00210901). AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Static anterior tibial translation (SATT) is radiographically measured to show the amount of tibial translation during the single-leg stance, and thus it is representative of the physiological axial load subjected to the anterior cruciate ligament (ACL) during the stance. Increased SATT has been associated with increased posterior tibial slope (PTS) and is also associated with increased graft failure., Purpose: To compare the SATT value in a control population with that in a population with an isolated ACL injury, as well as to compare the effect of tibial slope on SATT between the 2 groups., Study Design: Cohort study; Level of evidence, 3., Methods: A consecutive series of patients without ligamentous or meniscal injuries between 2019 and 2022 was reviewed. A matched consecutive cohort of patients with nonacute ACL injuries (surgery between 6 and 12 weeks after injury) without concomitant pathology was reviewed. Preoperative SATT and PTS were measured with a previously validated technique on lateral weightbearing knee radiographs. The SATT value was determined, and regression analysis was performed to investigate the relationship between SATT and PTS., Results: In total, 101 controls and 115 patients with an ACL injury were included in this study. The mean SATT was 1.31 mm (SD, 2.44 mm) and the mean PTS was 10.61° (SD, 3.28°) in the control cohort. The SATT was larger (mean, 2.27 mm; SD, 3.36 mm) in the ACL-injured cohort despite the tibial slope measurement being less in the ACL-injured cohort (mean, 9.46°; SD, 2.85°; P = .016). Linear regression analysis showed that for every 1° of increase in PTS, there was a 0.34-mm increase in SATT in the control cohort; however, there was a greater increase of 0.5 mm for every 1° of increase in PTS in the ACL-injured cohort. We found no significant differences in SATT when the cohorts were compared by age ( P = .26) or sex ( P = .10)., Conclusion: The present study reports a reference SATT value of 1.31 mm (SD, 2.44 mm) in a non-ACL-injured cohort, which was lower than in the ACL-injured cohort (mean, 2.27 mm; SD, 3.36 mm). The effect of slope on weightbearing anterior tibial translation was greater in the ACL-injured population than in the control cohort., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: High tibial osteotomy (HTO) is a successful joint-preserving procedure for the treatment of medial compartment osteoarthritis. Long-term survivorship of HTO ranges from 40% to 85%. There are consistent factors that predict failure., Purpose: To determine the 20-year survival of HTO and identify predictors of failure., Study Design: Case series; Level of evidence, 4., Methods: A total of 100 consecutive patients with medial bone-on-bone arthritis were prospectively studied to provide long-term patient-reported outcome measures after lateral closing-wedge HTO and determine the time to failure. Failure was defined as conversion to arthroplasty (total knee arthroplasty or unicompartmental knee arthroplasty) or revision HTO., Results: At 20 years, HTO survival was determined in 95 patients, and 5 were lost to follow-up. The overall survivorship of HTO at 20 years was 44%. The significant factors that were associated with better survivorship were age <55 years, body mass index <30, and Western Ontario and McMaster Universities Osteoarthritis Index pain score >45. These factors were used to define the favorable candidates. In the favorable candidates, survivorship was 100% at 5 years, after which there was a gradual decline to 62% survival at 20 years. Of those with HTO survival, 32 of 33 (97%) reported satisfaction with surgery, with a mean Knee injury and Osteoarthritis Outcome Score Pain score of 91 and Activities of Daily Living score of 97., Conclusion: HTO is a successful surgical option to treat medial compartment osteoarthritis and prevent the need for arthroplasty in young patients. The most suitable candidates for HTO are aged <55 years, are not obese, and have not progressed to severe symptomatic disability., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This study was supported by the Friends of the Mater Foundation, Sydney, Australia. J.P.R. has received consulting fees from Smith & Nephew and Pureplay Orthopaedic and nonconsulting fees from 360 Medcare. He holds stock or stock options in 360 Medcare. L.A.P. has received research support from Smith & Nephew and IP royalties from Australian Biotechnologies. He holds stock or stock options in Australian Biotechnologies. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Combined injury of the anterior cruciate ligament (ACL) and the medial collateral ligament (MCL) is a common injury pattern and accounts for 20% of all ligamentous knee injuries. Despite advancements in surgical technique, there is no up-to-date consensus regarding the superiority of nonoperative versus operative management in higher-grade MCL tears of combined ACL-MCL injuries., Purpose: To interpret recent literature on treatment options and to provide an updated evidence-based approach for management of combined ACL-MCL knee injuries., Study Design: Systematic review and meta-analysis; Level of evidence, 4., Methods: We performed a systematic review on outcomes following treatment of concomitant ACL and MCL injuries. A computerized search was conducted in PubMed, Embase.com, and Scopus.com. Authors independently assessed eligible studies and screened titles and abstracts. Articles reporting on patients with concomitant ACL and MCL injuries with or without concomitant procedures were included. Data regarding study design, sample size, patient age and sex, length of follow-up, timing of surgery, indications, surgical methods, concomitant procedures, outcomes, and complications were recorded. Patient-reported outcomes (PROs) and functional outcomes, including Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee scores, Lysholm and Tegner scores, and range of motion, were estimated via meta-analysis and compared statistically by surgical approach., Results: In total, 18 studies were included in the systematic review with level 1 to level 4 evidence, with a total of 1,534 cases, were included in the systematic review. Of these, 16 studies with sufficient statistical reporting including 997 cases with sufficient follow-up were included in meta-analysis. Three different approaches to combined ACL-MCL injuries were identified: ACL reconstruction with (1) nonoperative MCL, (2) MCL repair, and (3) MCL reconstruction. There was no statistical difference between nonoperative versus surgically managed MCL injuries for PROs, range of motion at final follow up, or quadriceps strength., Conclusion: Reconstruction of combined injury in a delayed fashion facilitates return of range of motion and may allow time for low-grade MCL tears to heal. If residual valgus or anteromedial rotatory laxity remains after a period of rehabilitation, then concomitant surgical management of ACL and MCL injuries is warranted. Avulsion MCL injuries and Stener-type lesions may benefit from early repair techniques., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Quality of life (QoL) is affected up to 5 years after an anterior cruciate ligament (ACL) injury. Knee impairment and osteoarthritis (OA) development increase over time, and this may affect QoL at a long-term follow-up., Purpose: To investigate changes in health- and knee-related QoL between 20 and 35 years after ACL injury and compare it between patients treated with or without ACL surgery, as well as to study how symptomatic OA (SOA) is associated with change in QoL., Study Design: Cohort study; Level of evidence, 2., Methods: Between 1980 and 1983, 139 patients with acute ACL rupture were allocated to surgical or nonsurgical treatment of the ACL. Both groups completed a structured rehabilitation program. Of those patients, 59 were followed for 20 and 35 years after ACL rupture. After 10 crossovers, 33 patients were treated with primary repair or ACL reconstruction, and 26 were treated without ACL surgery. Combined radiographic OA and knee symptoms at 35 years was defined as SOA. QoL was assessed at 20 and 35 years after injury with the Knee injury and Osteoarthritis Outcome Score QoL (KOOS-QoL) subscale (range, 1-100), ACL-QoL questionnaire (total score and 5 subscales; range, 1-100), European QoL-5 Dimensions Questionnaire, and visual analog scale. Results were analyzed with paired and independent-sample t tests and chi-square tests., Results: Knee-related QoL was impaired at both 20 and 35 years after ACL injury, and differences were dependent on the measurement outcome. In the total cohort, KOOS-QoL did not change but both total ACL-QoL score (7.1 points; 95% CI, 2.2-11.9) and 4 of 5 subscales (5-10 points) decreased ( P < .05). No differences were found between treatment groups. QoL decreased overall in patients with SOA, with a 21-point difference within-group change in KOOS-QoL (SOA or non-SOA) between 20 and 35 years of follow-up ( P = .001; Cohen d = 1.0)., Conclusion: An ACL injury impairs knee-related QoL for up to 35 years, with no difference between treatment approaches (initial repair or later reconstruction compared with nonsurgical treatment). The deterioration decreases with longer follow-up. Clinicians should be aware of differences in QoL depending on the measurement outcome., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: It is unclear how anterior cruciate ligament (ACL) reconstruction (ACLR) affects the development of osteoarthritis (OA). This uncertainty is partly caused by the lack of long-term studies on ACL injuries treated primarily without reconstruction and the underreporting of symptomatic OA., Purpose: To determine (1) the knee function, symptoms, and activity level, as well as the presence of radiographic and symptomatic OA; (2) how these clinical outcomes have changed over time; and (3) the frequency of subsequent knee surgeries after the index ACL injury in a cohort of patients with ACL injuries treated primarily without reconstruction., Study Design: Case series; Level of evidence, 4., Methods: A total of 100 patients underwent initial nonoperative treatment >30 years ago (mean, 33.2 ± 1.4 years). Of these, 81 patients (mean age, 59 ± 8 years) completed the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, and Tegner Activity Scale. Seventy-three patients underwent radiography to evaluate tibiofemoral and patellofemoral OA in the ACL-injured knee. Patients only underwent late ACLR if they experienced insufficient knee stability., Results: At 33 years after the ACL injury, the KOOS Activities of Daily Living subscore was better than population-based reference values, but scores were similar for the remaining KOOS subscales. Furthermore, 65% of patients had a good or excellent Lysholm score (≥84 points). The Tegner score decreased 4 points from before the injury to 33-year follow-up ( P < .001). Most patients (75%) had evidence of radiographic tibiofemoral and/or patellofemoral OA, but only 38% were classified as having symptomatic OA (defined as radiographic OA in combination with a symptomatic knee according to cutoffs on the KOOS). Approximately 50% underwent meniscal surgery, and 29% subsequently underwent ACLR for recurrent instability. There were 2 patients who underwent total knee replacement., Conclusion: Despite a high prevalence of radiographic OA, patients achieved acceptable subjective knee function and had a relatively low prevalence of symptomatic OA at >30 years after an ACL injury when an initial nonoperative treatment strategy was employed., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This study was financed by Swedish governmental funding of clinical research (ALF) and the Greta and Johan Kock Foundation. C.H. has received ALF funding for medical residents at Lund University in 2022; funding is allocated from the government to the health care system for clinicians to be able to perform clinical research for their doctoral thesis and was not provided for this article specifically. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Meniscal allograft transplantation (MAT) is an accepted and effective treatment option in the context of unsalvageable menisci, particularly in young and active patients. It has been shown to reduce pain and improve knee function in previously symptomatic patients. However, there is still limited knowledge about the long-term survival rates of allografts, the durability of clinical results, and the influence of patient-specific parameters, such as leg alignment, tibial slope, and preoperative International Cartilage Regeneration & Joint Preservation Society (ICRS) grade., Purpose: To determine (1) the long-term clinical success rate after MAT with bony fixation in a large, single-center cohort of consecutive patients, and (2) if patient-specific and procedural variables influence the clinical, anatomic, and subjective outcomes and risk of failure., Study Design: Case-control study; Level of evidence, 3., Methods: Data on 185 consecutive knees undergoing MAT in a single institution were prospectively collected and screened for inclusion in this study. The minimum follow-up time was 2 years. Radiographic variables (ICRS grade and Kellgren-Lawrence grade) were assessed preoperatively and at follow-up. Subjective patient-reported outcome measures (PROMs) (Lysholm score, Knee injury and Osteoarthritis Outcome Score [KOOS] including subscores, International Knee Documentation Committee [IKDC] score, and visual analog scale [VAS] score) were collected preoperatively and at follow-up. Clinical failure was defined as revision surgery due to graft failure or conversion to total knee arthroplasty. Anatomic failure was considered a tear covering >20% of the allograft, any peripheral tear, and unstable peripheral fixation leading to dislocation of the graft. Subjective failure was defined as Lysholm score ≤65. Preoperative tibial slope and leg alignment were assessed. Survival analyses were performed using the Kaplan-Meier estimate. Univariate and multivariate analyses were performed to determine risk factors for clinical and anatomic failure., Results: A total of 157 knees met inclusion criteria. After a mean follow-up time of 7 ± 3.5 years, 127 (80.9%) knees were free of clinical, anatomic, and subjective failure. Fourteen (8.9%) knees experienced clinical failure, 26 (16.6%) knees were identified as having experienced anatomic failure, and 13 (8.3%) patients experienced subjective failure with a reported Lysholm score of ≤65 at a mean follow-up of 7 years. Concurrent osteochondral allograft transplantation was identified as a predictor of both clinical (hazard ratio [HR], 4.55; 95% CI, 1.46-14.17; P = .009) and anatomic (HR, 3.05; 95% CI, 1.34-6.92; P = .008) failure. Cartilage damage of ICRS grade 3 or 4 of the index compartment conveyed an increased risk for clinical (HR, 3.41; 95% CI, 1.05-11.01; P = .04) and anatomic (HR, 3.04; 95% CI, 1.31-7.11; P = .01) failure. High-grade cartilage damage preoperatively (HR, 10.67; 95% CI, 1.037-109.768; P = .046), patient age >25 years (HR, 5.44; 95% CI, 0.120-246.070; P = .384), and a body mass index >30 (HR, 2.24; 95% CI, 0.748-6.705; P = .149) were associated with subjective failure. PROMs including KOOS and IKDC were significantly improved at final follow-up compared with preoperative scores across all measurements ( P < .005)., Conclusion: MAT showed good to excellent clinical results at a mean follow-up of 7 years. Low ICRS lesion grade was associated with a higher clinical and anatomic survival rate. Patients with concurrent OCA transplantation are at a higher risk of clinical and anatomic failure, but still report significantly improved PROMs. These results suggest that MAT has a lasting beneficial effect both in isolation and in complex cases with ≥1 concurrent procedures., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: M.H. was funded by Deutsche Forschungsgemeinschaft (DFG; German Research Foundation) Projektnummer 466023693. The authors acknowledge support from the Foderaro-Quattrone Musculoskeletal-Orthopaedic Surgery Research Innovation Fund. M.J.S. has received royalties, consulting fees, and compensation for services other than consulting from Arthrex Inc; and research support from Stryker. B.A.L. has received royalties, consulting fees, and compensation for services other than consulting from Arthrex Inc; consulting fees from Smith + Nephew; and speaking fees from Linvatec. D.B.F.S. has received consulting fees from Smith + Nephew and research support from JRF. A.J.K. has received research support from Aesculap/B.Braun, Arthrex, Arthritis Foundation, Ceterix, and Histogenics; consulting fees from Arthrex, JRF Ortho, Vericel, and Responsive Arthroscopy; royalties from Arthrex and Responsive Arthroscopy; honoraria from JRF, Vericel, and Musculoskeletal Transplant Foundation; grant from DJO; and personal fees from Ceterix Orthopaedic, Gemini Mountain Medical, and Smith + Nephew. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Objective: Periprosthetic fracture (PPF) is an uncommon but devastating complication after total knee arthroplasty (TKA). Anterior femoral notching (AFN) is one of a perioperative risk factor for PPF. The main purpose of this study was to compare between the rates of anterior femoral notching (AFN) and supracondylar periprosthetic femoral fracture (sPPF) of manual TKA and robotic arm-assisted TKA (RATKA). Meanwhile, blood loss, transfusion rates, inflammatory responses, complications, early clinical and radiological outcomes were also assessed., Methods: This retrospective study included 330 patients (133 RATKA and 197 manual TKA). Differences in risks of inflammatory, blood loss, complications (periprosthetic fracture and periprosthetic joint infection), pre-operative and post-operative distal lateral femoral angle (LDFA), distal femoral width (DFW), prosthesis-distal femoral width (PDFW) ratio, AFN, femoral component flexion angle (FCFA), peri-operative and post-operative functional outcomes between the RATKA and manual TKA groups were compared., Results: The operation time and postoperative CRP level in the RATKA group was significantly longer and higher than that in the manual TKA group ( p < .001). However, there was no significant difference in postoperative WBC level ( p = .217), hemoglobin loss ( p = .362), postoperative drainage ( p = .836), and periprosthetic fracture ( p = 1.000). There was no significant difference in LDFA ( p > .05), DFW( p = .834), PDFW ratio ( p = .089) and FCFA ( p = .315) between the two groups, but the rate of AFN in the RATKA group was significantly lower than that in the manual TKA group ( p < .05). There was no significant difference in ROM between the two groups on POD3, POD 90 and 1 year ( p < .05), but the FJS-12 score in the RATKA group was higher than that in the manual TKA group on 1 year ( p = .001)., Conclusion: Robotic-assisted total knee arthroplasty can decrease the incidence of anterior femoral notching compared to posterior referenced instrumented total knee arthroplasty., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Arthrogenic muscle inhibition (AMI) is a process in which neural inhibition after injury or surgery to the knee results in quadriceps activation failure and knee extension deficit., Purpose: To determine the incidence and spectrum of the severity of AMI after acute anterior cruciate ligament (ACL) injury using the Sonnery-Cottet classification, to determine the interobserver reliability of the classification system, and to investigate potential important factors associated with AMI after ACL injury., Study Design: Case-control study; Level of evidence, 3., Methods: Consecutive patients who had an acute ACL injury between October 2021 and February 2022 were considered for study inclusion. Eligible patients underwent a standardized physical examination at their first outpatient appointment. This included an assessment of quadriceps inhibition, identification of any extension deficits, and grading of AMI and its reversibility according to the Sonnery-Cottet classification., Results: A total of 300 consecutive patients with acute ACL ruptures were prospectively enrolled in the study. Of them, 170 patients (56.7%) had AMI. Patients evaluated with AMI showed a significantly inferior Lysholm score, International Knee Documentation Committee score, Simple Knee Value, and Knee injury and Osteoarthritis Outcome Score than patients without AMI ( P < .0001). Multivariate analysis revealed that the presence of effusion, concomitant injuries, and high pain scores were associated with a significantly greater risk of AMI. Additional associations with the presence of AMI included a short duration between injury and evaluation, the use of crutches, and using a pillow as a support at night. In contrast, a previous ACL injury was associated with significantly lower odds of developing AMI (OR, 0.025; 95% CI, 0-0.2; P = .014). Among the 170 patients with AMI, 135 patients (79%) showed a resolution of their inhibition at the end of the consultation after application of simple exercises; the remaining 35 patients required specific rehabilitation. Interobserver reliability of the classification system was almost perfect (95% CI, 0.86-0.99)., Conclusion: AMI occurs in over half of patients with acute ACL injuries. When it occurs, it is easily reversible in the majority of patients with simple exercises targeted at abolishing AMI. The presence of "red flags" should increase the index of suspicion for the presence of AMI, and these include the presence of an effusion, high pain scores, a short time between injury and evaluation, multiligament injuries, the use of crutches, and using a pillow as a support at night. Patients with a history of ipsilateral or contralateral ACL injury are at a significantly lower risk of AMI than those with a first-time ACL injury., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: B.S.C. has received consulting fees and royalties from Arthrex. J.M.F. is consultant for Arthrex and New Clip Technics. M.T. is a consultant for Arthrex. E.C. is a consultant for Arthrex. G.P.H. has received a fellowship grant from Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: The single-radius design is one of the major total knee arthroplasty (TKA) designs and widely used all over the world. The objective of this study was to compare in vivo kinematics between the anteroposterior (AP) single-radius design with mediolateral (ML) single-radius (Non Restricted Geometry; NRG) and ML dual-radius (Triathlon) during stair activities., Methods: A total of 21 knees in 18 patients (NRG group: 10 knees in 7 patients, Triathlon group: 11 knees in 11 patients) with a clinically successful posterior stabilized TKA were examined. Under fluoroscopic surveillance, each patient performed stair ascending and descending motions. In vivo kinematics were analyzed using 2D/3D registration technique. The knee flexion angle, rotation angle, varus-valgus angle, AP translation of the femorotibial contact point for both the medial and lateral sides of the knee, and post-cam engagement were evaluated., Results: There were no significant differences between the two groups in rotation angle and AP translation at each flexion angle. Examining the varus-valgus angle, the NRG group showed varus position at an early flexion angle during both stair activities.Post-cam engagement was observed in both groups during both stair activities. The mean flexion angle of engagement in the NRG group, the post of which was located anterior to the Triathlon, was larger than that in the Triathlon group during both stair activities., Conclusion: Despite the same AP single-radius TKA, ML single-radius might affect varus motion at an early flexion angle., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.