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Background:During high tibial osteotomy (HTO), the superficial medial collateral ligament (sMCL) is cut or released at any degree to expose the osteotomy site and achieve the targeted alignment correction according to the surgeon’s preference. However, it is still unclear whether transection of sMCL increases valgus laxity.Purpose:We aimed to assess the outcomes and safety of sMCL transection, especially focusing on iatrogenic valgus instability.Study Design:Case series; Level of evidence, 4.Methods:Seventy-two patients (89 knees) who underwent medial open wedge HTO (MOWHTO) with transection of the sMCL between October 2013 and September 2018 were retrospectively investigated. Clinical evaluations, including the International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Tegner and Lysholm scores, were performed preoperatively and at 2 years postoperatively. The radiographic parameters hip-knee-ankle (HKA) angle, joint line convergence angle on standing radiographs (standing JLCA), and weightbearing line (WBL) ratio were assessed preoperatively and at 3 months, 6 months, 1 year, and 2 years postoperatively. To evaluate valgus laxity, we assessed the valgus JLCA and medial joint opening (MJO) at the aforementioned time points using valgus stress radiographs.Results:All clinical results at the 2-year follow-up were significantly improved compared with those obtained at the preoperative assessment ( P < .001). The postoperative HKA angle significantly differed from the preoperative one, and no significant valgus progression was observed during follow-up (preoperative, 8.5°± 2.7°; 3 months, –3.5°± 2.0°; 6 months, –3.2°± 2.3°; 1 year, –3.1°± 2.3°; 2 years, –2.9°± 2.5°; P < .001) The mean WBL ratio was 62.5% ± 9.0% at 2 years postoperatively. The postoperative valgus JLCA at all follow-up points did not significantly change compared with the preoperative valgus JLCA (preoperative, –0.1°± 2.1°; 3 months, –0.2°± 2.4°; 6 months, –0.1°± 2.5°; 1 year, 0.1°± 2.5°; 2 years, 0.2°± 2.2°) The postoperative MJO at all follow-up points did not significantly change compared with the preoperative MJO (preoperative, 7.1 ± 1.7 mm; 3 months, 7.0 ± 1.7 mm; 6 months, 6.9 ± 1.9 mm; 1 year, 6.7 ± 1.8 mm; 2 years, 6.8 ± 1.8 mm).Conclusion:Transection of the sMCL during MOWHTO does not increase valgus laxity and could yield desirable clinical and radiographic results.

Purpose The purpose of this study is to classify the discoid lateral meniscus (DLM) according to the signal and shape in magnetic resonance imaging (MRI), and to provide information not only in diagnosis but also in treatment. Materials and Methods We reviewed 162 cases who diagnosed with DLM by MRI and underwent arthroscopic procedures from April 2010 to March 2018. Three observers reviewed MRI findings of all cases and predicted arthroscopic tear using three MRI criteria (criterion 1,2 and 3). Among three criteria, the criterion that most accurately predicts arthroscopic tear was selected. Using this criterion, the cases of predicted tear were named group 1. In addition, group 1 was divided into three subgroups (group 1a, 1b and 1c) by deformation or displacement on MRI and arthroscopic type of tear and procedures were analyzed according to these subgroups. Results The intra-meniscal signal change itself (criterion 3) on MRI showed the highest agreement with the arthroscopic tear. No meniscal deformation and displacement on MRI (group 1a) showed no specific type of tear and more cases of meniscal saucerization. The meniscal deformation on MRI (group 1b) showed more simple horizontal tears and more cases of meniscal saucerization. The meniscal displacement on MRI (group 1c) showed more peripheral tears and more cases of meniscal repair and subtotal meniscectomy. Comparing arthroscopic type of tear and type of arthroscopic procedure between three subgroups, there were significant differences in three groups (P Conclusions Intra-meniscal signal change itself on MRI is the most accurate finding to predict arthroscopic tear in symptomatic DLM. In addition, subgroup analysis by deformation or displacement on MRI is helpful to predict the type of arthroscopic tear and procedures.

This study aimed to evaluate the infection control rate of palliative arthroscopic debridement, antibiotics, and implant retention (DAIR) for the high mortality risk or terminal cancer stage patients.From March 2018 to August 2021, 21 patients met the following inclusion criteria: old age of more than 80, diagnosed as a terminal stage of cancer, high risk of mortality and morbidity representing as Charlson comorbidity index (CCI) ≥ 5, low daily activity with disabled extremity, and re-infection after two-stage revision. Each patient underwent arthroscopic DAIR and additional continuous irrigation for 48 hours. The need for subsequent re-arthroscopic DAIR or two-stage revision was determined by the post-operative trends of C-reactive protein (CRP) levels. Infection control was defined as continuing controlled status of infection based on clinical and laboratory results by one or two times of arthroscopic DAIR within initial two months. Treatment failure was defined as more than three times arthroscopic debridement, two-stage revision surgery, or expired due to uncontrolled infection.Arthroscopic DAIR controlled the infection in 19 (90.5%) of the 21 cases. The other knee underwent a total of three times of re-arthroscopic DAIR and the other one underwent two-stage revision. Although five patients expired during the follow-up period due to worsening medical problems or terminal cancer, there were no deaths from uncontrolled infection, sepsis, or surgery-related complications.Arthroscopic debridement with continuous irrigation for the infection TKA with high mortality risk or terminal cancer patients showed a 90.5% infection control rate. For high-risk patients, arthroscopic debridement with continuous irrigation can be an alternative treatment to improve the quality of life during survival.

Background and Objectives: Intraarticular injection of tranexamic acid (IA-TXA) plus drain-clamping is a preferred method of reducing bleeding after total knee arthroplasty (TKA). However, no consensus has been reached regarding the timing of the clamping. The purpose of this study was to determine the optimum duration of drain-clamping after TKA with IA-TXA. Materials and Methods: We retrospectively reviewed 151 patients that underwent unilateral TKA with IA-TXA plus drain-clamping for 30 min, 2 h, or 3 h. The total drained volume was reviewed as the primary outcome, and hematocrit (Hct) reductions, estimated blood loss (EBL), transfusion rates, and wound complications were reviewed as secondary outcomes. Results: The mean total drained volume, Hct reduction, and EBL were significantly less in the 3 h group than in the 30 min group. Between the 2 h and 3 h groups, there was no statistical difference in the mean total drained volume, Hct reduction, or EBL. The proportion of patients who drained lesser than 300 mL was high in the 3 h group. No significant intergroup difference was observed for transfusion volume, transfusion rate, and wound related complications. Conclusions: In comparison of the IA-TXA plus drain-clamping after TKA, there was no difference in EBL between the 2 h group and the 3 h group, but the amount of drainage volume was small in the 3 h group.

Background:Achieving the postoperative mechanical axis passing through 62.5% of the tibial plateau is considered successful osteotomy surgery. Despite precise preoperative planning and surgical techniques, some procedures result in under- or overcorrection. Few studies have investigated the relationship between clinical outcomes and unintentional under- or overcorrection after open wedge high tibial osteotomy (OWHTO) using whole-leg standing radiographs.Purpose:To investigate the relationship between postoperative alignment using whole-leg standing radiographs and clinical outcomes after OWHTO.Study Design:Cohort study; Level of evidence, 3.Methods:A total of 89 knees (72 patients) that underwent OWHTO between October 2013 and September 2018 were included. Patients with postoperative weightbearing line (WBL) ratios within 57% to 67% were classified as appropriate correction (group A; 45 cases), whereas ratios 67% were classified as undercorrection (group U; 20 cases) and overcorrection (group O; 24 cases), respectively. The following patient-reported outcomes (PROs) were investigated: International Knee Documentation Committee (IKDC) subjective score, Kujala score, and Knee injury and Osteoarthritis Outcome Score (KOOS). The correlation between postoperative WBL and PROs was analyzed. PROs were compared among the 3 groups.Results:Regarding the correlation between postoperative WBL ratio and PROs, a larger postoperative WBL ratio was significantly correlated with a poor IKDC subjective score ( P = .002), Kujala score ( P = .009), and KOOS. Group O showed inferior postoperative PRO scores when compared with group A or U, whereas group U showed a similar result to group A (mean IKDC subjective scores: group U, 62.0; group A, 61.2; group O, 47.6; P = .004).Conclusion:Overcorrection after OWHTO surgery correlated with inferior PROs; therefore, overcorrected alignment should be avoided for patient satisfaction. Knees with an undercorrected alignment showed clinical results similar to those with appropriate correction.

Background:Time-dependent changes in lower extremity alignment after an opening-wedge high tibial osteotomy (OWHTO) have been poorly investigated. Moreover, few studies have investigated risk factors of postoperative alignment change.Purposes:To investigate time-dependent alignment changes and identify predictive factors for postoperative alignment change after OWHTO.Study Design:Case-control study; Level of evidence, 3.Methods:This study included patients who underwent OWHTO between March 2010 and September 2018. A total of 142 knees with a mean follow-up of 42 months were included and classified as the change group when the amount of hip-knee-ankle (HKA) angle change was >1°; if otherwise, then as the no-change group. HKA angle was obtained at 6 time points: preoperatively and at 3 months, 6 months, 1 year, 2 years, and final follow-up postoperatively. Multiple regression analysis was performed to identify the factors that were correlated with the changes in the HKA angle from 3 months to the final follow-up.Results:Among the 142 knees, 59 (42%) were included in the change group. The overall postoperative HKA angles progressed serially toward varus after OWHTO. The mean angles of the 6 time points were 8.5°, –3.7°, –3.6°, –3.3°, –3.1°, and –2.7°, respectively. The mean HKA angles of the change and no-change groups were 9.1°, –4.3°, –3.4°, –2.8°, –2.0°, and –1.4° and 8.1°, –3.3°, –3.8°, –3.6°, –3.8°, and –3.7°, respectively. Greater change in the HKA angle was predicted by preoperatively greater valgus stress joint line convergence angles and less medial joint space width.Conclusion:Of the cases of OWHTO, 42% showed correction loss of >1° at a mean follow-up of 42 months. The overall postoperative HKA angles progressed serially to varus angles after OWHTO. Preoperative greater valgus stress joint line convergence angles and less medial joint space width were predictive factors for greater change in alignment toward varus after OWHTO.

Bone graft is required in various surgical procedures. Although autograft is the gold standard, it has limited availability. Various compounds have been proposed as alternatives such as biphasic calcium phosphate (BCP), which is the most widely used compound. The newly synthesized microporous sphere-shaped BCP has the advantage of increasing contact surface, and it can induce the formation of microbone structures. A putty-type contains the addition of a fluid carrier to the sphere-shaped BCP and can be easily used for a small orifice large bone defect. To compare the widely used BCP products, new bone formation and residual graft materials (RGM) were evaluated for 6 and 12 weeks in a rabbit calvarial bone defect model. Although existing BCP products and the microporous sphere-type product did not differ significantly with respect to new bone formation and RGM, the putty-type product was largely washed out and had low new bone formation at 6 and 12 weeks. Overall, the results suggest that microporous sphere-shaped BCP showed similar bone formation capability to existing products and was able to maintain higher initial mechanical stability.

Osteoarthritis (OA) has generally been introduced as a degenerative disease; however, it has recently been understood as a low-grade chronic inflammatory process that could promote symptoms and accelerate the progression of OA. Current treatment strategies, including corticosteroid injections, have no impact on the OA disease progression. Mesenchymal stem cells (MSCs) based therapy seem to be in the spotlight as a disease-modifying treatment because this strategy provides enlarged anti-inflammatory and chondroprotective effects. Currently, bone marrow, adipose derived, synovium-derived, and Wharton’s jelly-derived MSCs are the most widely used types of MSCs in the cartilage engineering. MSCs exert immunomodulatory, immunosuppressive, antiapoptotic, and chondrogenic effects mainly by paracrine effect. Because MSCs disappear from the tissue quickly after administration, recently, MSCs-derived exosomes received the focus for the next-generation treatment strategy for OA. MSCs-derived exosomes contain a variety of miRNAs. Exosomal miRNAs have a critical role in cartilage regeneration by immunomodulatory function such as promoting chondrocyte proliferation, matrix secretion, and subsiding inflammation. In the future, a personalized exosome can be packaged with ideal miRNA and proteins for chondrogenesis by enriching techniques. In addition, the target specific exosomes could be a gamechanger for OA. However, we should consider the off-target side effects due to multiple gene targets of miRNA.

During high tibial osteotomy (HTO), the superficial medial collateral ligament (sMCL) is cut or released at any degree to expose the osteotomy site and achieve the targeted alignment correction according to the surgeon's preference. However, it is still unclear whether transection of sMCL increases valgus laxity.We aimed to assess the outcomes and safety of sMCL transection, especially focusing on iatrogenic valgus instability.Case series; Level of evidence, 4.Seventy-two patients (89 knees) who underwent medial open wedge HTO (MOWHTO) with transection of the sMCL between October 2013 and September 2018 were retrospectively investigated. Clinical evaluations, including the International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Tegner and Lysholm scores, were performed preoperatively and at 2 years postoperatively. The radiographic parameters hip-knee-ankle (HKA) angle, joint line convergence angle on standing radiographs (standing JLCA), and weightbearing line (WBL) ratio were assessed preoperatively and at 3 months, 6 months, 1 year, and 2 years postoperatively. To evaluate valgus laxity, we assessed the valgus JLCA and medial joint opening (MJO) at the aforementioned time points using valgus stress radiographs.All clinical results at the 2-year follow-up were significantly improved compared with those obtained at the preoperative assessment (Transection of the sMCL during MOWHTO does not increase valgus laxity and could yield desirable clinical and radiographic results.

Direct energy deposition (DED) is a newly developed 3D metal printing technique that can be utilized on a porous surface coating of joint implants, however there is still a lack of studies on what advantages DED has over conventional techniques. We conducted a systematic mechanical and biological comparative study of porous coatings prepared using the DED method and other commercially available technologies including titanium plasma spray (TPS), and powder bed fusion (PBF). DED showed higher porosity surface (48.54%) than TPS (21.4%) and PBF (35.91%) with comparable fatigue cycle. At initial cell adhesion, cells on DED and PBF surface appeared to spread well with distinct actin stress fibers through immunofluorescence study. It means that the osteoblasts bind more strongly to the DED and PBF surface. Also, DED surface showed higher cell proliferation (1.27 times higher than TPS and PBF) and osteoblast cell activity (1.28 times higher than PBF) for 2 weeks culture in vitro test. In addition, DED surface showed better bone to implant contact and new bone formation than TPS in in vivo study. DED surface also showed consistently good osseointegration performance throughout the early and late period of osseointegration. Collectively, these results show that the DED coating method is an innovative technology that can be utilized to make cementless joint implants.

Background: Intraarticular injection of tranexamic acid (IA-TXA) plus drain-clamping is a preferred method of reducing bleeding after total knee arthroplasty (TKA). However, no consensus had been reached regarding the timing of clamping. The purpose of this study was to determine the optimum duration of drain-clamping after TKA with IA-TXA.Methods: We retrospectively reviewed 151 patients that underwent unilateral TKA with IA-TXA plus drain-clamping for 30 minutes (Group A, 60 patients), 2 hours (Group B, 42 patients), or 3 hours (Group C, 49 patients). Total drained volumes, hematocrit (Hct) reductions, estimated blood losses (EBLs), transfusion rates, and wound complications were reviewed.Results: Mean total drained volume, Hct reduction, EBL, and transfusion rate were significantly less in group C than in groups A or B (p < 0.01). No significant intergroup difference was found for wound-related complications. No surgical site infection or deep vein thrombosis was observed.Conclusion: IA-TXA plus drain-clamping for 3 hours is optimal for reducing blood loss with minimal complications after TKA.

Background With the development of health care–related mobile apps, attempts have been made to implement remote patient-reported outcome measures (PROMs). In order for remote PROMs to be widely used by mobile apps, the results should not be different depending on the location; that is, remote PROM results performed in locations other than hospitals should be able to obtain reliable results equivalent to those performed in hospitals, and this is very important. However, to our knowledge, there are no studies that have assessed the reliability of PROMs using mobile apps according to the location by comparing the results performed remotely from the hospital and performed at the outpatient visits. Objective The purpose of this study was to evaluate the reliability of remote PROMs using mobile apps compared to PROMs performed during outpatient follow-up visits after arthroscopic shoulder surgery. Methods A total of 174 patients who underwent arthroscopic rotator cuff repair completed questionnaires 2 days before visiting the clinic for the 1-, 2-, 3-, 6-, and 12-month follow-ups (test A). The patients completed the questionnaires at the clinic (test B) using the same mobile app and device for the 1-, 2-, 3-, 6-, and 12-month follow-ups. Test-retest comparisons were performed to analyze the differences and reliability of the PROMs according to the period. Results Comparisons of tests A and B showed statistically significant differences at 1, 2, and 3 months (all Ps.05). The intraclass correlation values between the two groups were relatively low at the 1-, 2-, and 3-month follow-ups but were within the reliable range at 6 and 12 months after surgery. The rate of completion of tests A and B using the mobile app was significantly lower in the group older than 70 years than in the other groups for all postoperative periods (P Conclusions PROMs using mobile apps with different locations differed soon after surgery but were reliably similar after 6 months. The remote PROMs using mobile apps could be used reliably for the patient more than 6 months after surgery. However, it is to be expected that the use of mobile app–based questionnaires is not as useful in the group older than 70 years as in other age groups.

BackgroundWith the developments in the arthroscopic technique, anterior cruciate ligament (ACL) remnant-preserving reconstruction is gradually gaining attention with respect to improving proprioception and enhancing early revascularization of the graft. To evaluate the mechanical pull-out strength of three different methods for remnant-preserving and re-tensioning reconstruction during ACL reconstruction.MethodsTwenty-seven fresh knees from mature pigs were used in this study. Each knee was dissected to isolate the femoral attachment of ACL and cut the attachment. An MTS tensile testing machine with dual-screw fixation clamp with 30° flexion angle was used. The 27 specimens were tested after applying re-tensioning sutures with No. 0 polydioxanone (PDS), using the single stitch (n = 9), loop stitch (n = 9), and triple stitch (n = 9) methods. We measured the mode of failure, defined as (1) ligament failure (longitudinal splitting of the remnant ACL) or (2) suture failure (tearing of the PDS stitch); load-to-failure strength; and stiffness for the three methods. Kruskal-Wallis test and Mann-Whitney U-test were used to compare the variance of load-to-failure strength and stiffness among the three groups.ResultsLigament failure occurred in all cases in the single stitch group and in all but one case in the triple stitch group. Suture failure occurred in all cases in the loop stitch group and in one case in the triple stitch group. The load-to-failure strength was significantly higher with loop stich (91.52 ± 8.19 N) and triple stitch (111.1 ± 18.15 N) than with single stitch (43.79 ± 11.54 N) (p = 0.002). With respect to stiffness, triple stitch (2.50 ± 0.37 N/mm) yielded significantly higher stiffness than the other methods (p = 0.001).ConclusionsThe results suggested that loop stitch or triple stitch would be a better option for increasing the mechanical strength when applying remnant-preserving and re-tensioning reconstruction during ACL reconstruction.

By increasingly recognized importance of femoral tunnel position on restoration of native knee kinematics, use of the anteromedial portal (AMP) for establishment of the femoral tunnel is growing interest. The AMP technique is meant to allow for more anatomic femoral tunnel position. To perform easily, appropriate portal formation is the key to the AMP technique. To avoid crowding and jamming of instrument through the AM and additional anteromedial (AAM) portal, it is recommended to make the portals at least 1.5 cm space. The bony anatomy of the lateral femoral condyle is helpful in locating the boundaries of native ACL. Femoral tunnel would be made by using flexible guide and with hyperflexed knee position. Slightly medial positioned tibial tunnel in the native ACL footprint can reduce the risk of graft impingement. After graft passage, the endobutton CL is flipped on the lateral femoral cortex. Before final securing, the position of button should be checked under C-arm fluoroscopy. Finally, the tibial side of graft is secured with bio-absorbable interference screw in full extension with tibiofemoral reduction force. Despite there are the technical challenges associated with AMP technique, complications can be avoided with understanding of the potential pitfalls and technical principles.

Medial open-wedge high tibial osteotomy is an established treatment option for relatively young patients with medial-compartment osteoarthritis and varus deformity. This procedure is mainly focused on correcting coronal malalignment; however, it inevitably affects the posterior tibial slope (PTS) in the sagittal plane. The alteration of the PTS significantly affects knee stability and kinematics. When medial open-wedge high tibial osteotomy is performed, incomplete osteotomy of the posterior cortex could lead to a cortical hinge shift from the lateral side to the posterolateral side, which indicates the alteration of the axial hinge axis. In this case, there is a risk of an increasing PTS. In addition, incomplete posterior cortex osteotomy can lead to a lateral hinge fracture.

Background: Unstable trochanteric femur fractures in elderly patients with osteoporosis are still challenging. Gamma3 nail with the U-blade lag screw (U-blade gamma nail) has been developed to improve mechanical stability of proximal femoral fragment. This study aimed to compare the clinical and radiologic outcomes of U-blade gamma nail to proximal femoral nail antirotation (PFNA), and standard Gamma3 nail (gamma nail) for unstable trochanteric femur fractures. Methods: A retrospective matched-pair case study was performed with U-blade gamma nail, PFNA, and gamma nail. During 2012-2018, 970 patients with unstable trochanteric femur fractures were reviewed. Matching criteria were set as follows: 1) sex; 2) age (± 3 years); 3) body mass index (± 2 kg/m2); 4) bone mineral density (± 1 T-score in femur neck). Finally, a total of 159 patients were enrolled. We assessed the tip-apex distance (TAD), neck shaft angle, and hip screw sliding distance using plain radiographs. Also, we evaluated the clinical outcomes with Koval’s grade and fixation failure during 2 years. Results: The mean postoperative TAD was not significantly different among the 3 groups (p = 0.519). However, the change in the TAD at 1 year (p = 0.027) and 2 years (p = 0.008) after surgery was significantly smaller in U-blade gamma nail group compared with PFNA and gamma nail group. The hip screw sliding distance at 1 year (p = 0.004) and 2 years (p = 0.001) after surgery was significantly smaller in U-blade gamma nail group compared with PFNA and gamma nail group. However, there was no significant difference of Koval’s grade and fixation failure among the 3 groups (p = 0.535). Conclusion: U-blade gamma nail showed favorable radiologic results in terms of the change in the hip screw position. However, U-blade gamma nail was not superior to PFNA and gamma nail in clinical outcomes.

Medial meniscus posterior root tear is a disruptive injury causing significant sequelae. Several techniques to repair and maintain the native function of the medial meniscus have been introduced, but limitations have been reported in terms of their results. In this current note, the authors introduce the arthroscopic transtibial pull-out repair with whip running suture technique, which may not only avoid the potential risk of meniscus cut-through by the suture material but also optimize the reduction of the extruded meniscus. By suturing the posteromedial capsule and peripheral meniscus, more medialization force can be directly applied to the extruded part of the meniscus, and normal hoop tension can be restored., Technique Video Video 1 Step-by-step description of the arthroscopic pull-out repair of medial meniscus posterior root tear with whip running suture technique. The video shows the arthroscopy of the left knee. Standard anterolateral and anteromedial portal are used for the initial inspection. After the posteromedial and posterolateral portal are made using the transillumination technique, the posterior trans-septal portal is established. The main procedures of this technique are done under visualization through the trans-septal portal with a 30° scope. After establishing the healing bed for the root repair, guide pin is inserted with the ACL drilling guide (110° setting; Arthrex, Naples, FL). Then, a 45° curved suture hook loaded with a no. 2 PDS suture material is inserted through the posteromedial portal. The posterior capsule and the medial meniscus posterior horn on the posteromedial corner are penetrated by the suture hook. The sharp tip of the suture hook is advanced from the posterior capsule into the femoral surface of the medial meniscus. At the point 5 mm lateral to the first penetration, the posterior horn of the medial meniscus is penetrated by the same suture hook loaded with a no. 1 nylon suture material from the tibial side to the femoral side in a vertical direction. Using the shuttle relay technique, the second suture of the nylon is exchanged with the first suture of the PDS. At this stage, the whip running stitch involving the posteromedial capsule is completed. Using a crescent suture hook loaded with a no. 2 PDS, the simple vertical suture is made penetrating the root stump 5 to 10 mm medial to the stump end. At the point 5 mm apart from the previous suture, the third suture is done using the same crescent hook and suture material. In this stage, 1 whip running suture and 2 simple vertical sutures are completed. After reaming the trans-tibial tunnel for pulling out the suture strands, a wire loop is advanced through the reamer into the posteromedial portal. After checking all 6 strands of the 3 sutures are engaged properly within the wire loop, the wire is withdrawn out of the tibial tunnel. Under the maintenance of such adequate tension, the PDS strands are post-tied and fixed with a 3.5 mm cortical screw and washer on anterior cortex of the tibia. (PDS, polydioxanone.)

Background: For total knee arthroplasty (TKA), implant design and proper coverage are important for achieving patient satisfaction. An asymmetrical anatomic implant (Persona® knee system, Zimmer Biomet, Warsaw, Indiana) enables accurate coverage and minimal bone cutting. This study aimed to analyze the clinical and radiological outcomes of TKA using an asymmetrical anatomic implant over a minimum 3-year follow-up.Methods: The medical records of 94 patients who underwent 132 TKAs using the Persona® knee system, between April 2015 and January 2016 were reviewed. Pre- and post-operative clinical outcomes (assessed using the International Knee Documentation Committee (IKDC), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and Knee Injury and Osteoarthritis Outcome Score (KOOS) scores, and range of motion (ROM) were reviewed. The mechanical hip-knee-ankle (HKA) axis, component overhang and underhang and presence of a radiolucent line (RLL) were evaluated. Liner thickness were also reviewed.Results: At 3-year follow-up, the mean ROM improved from 108.4° to 130.3°. The mean IKDC subjective, WOMAC and global KOOS score significantly improved from 29.2 to 70.3, from 64.2 to 11.5, and from 66.6 to 21.7, respectively (p The mean mechanical HKA axis indicated the correction of the malalignment (from 9.2° varus to 0.3° varus, p3-mm bone-to-implant size mismatch were 6.8% and 8.3% for the femoral and tibial components, respectively. RLL was found in seven cases, but they were small (>2 mm) and did not progress. In 36.3% of the knees, the additional liner thickness (11 or 13mm) was used. No case of implant loosening or early failure related to the implant design occurred. Conclusion: TKA using the Persona® knee system improved all the clinical knee scores and ROM without signs of early failure. This knee system also provides more implant size options than the conventional TKA systems and facilitates ligament balancing.

BACKGROUND With the development of health care–related mobile apps, attempts have been made to implement remote patient-reported outcome measures (PROMs). In order for remote PROMs to be widely used by mobile apps, the results should not be different depending on the location; that is, remote PROM results performed in locations other than hospitals should be able to obtain reliable results equivalent to those performed in hospitals, and this is very important. However, to our knowledge, there are no studies that have assessed the reliability of PROMs using mobile apps according to the location by comparing the results performed remotely from the hospital and performed at the outpatient visits. OBJECTIVE The purpose of this study was to evaluate the reliability of remote PROMs using mobile apps compared to PROMs performed during outpatient follow-up visits after arthroscopic shoulder surgery. METHODS A total of 174 patients who underwent arthroscopic rotator cuff repair completed questionnaires 2 days before visiting the clinic for the 1-, 2-, 3-, 6-, and 12-month follow-ups (test A). The patients completed the questionnaires at the clinic (test B) using the same mobile app and device for the 1-, 2-, 3-, 6-, and 12-month follow-ups. Test-retest comparisons were performed to analyze the differences and reliability of the PROMs according to the period. RESULTS Comparisons of tests A and B showed statistically significant differences at 1, 2, and 3 months (all PsPs>.05). The intraclass correlation values between the two groups were relatively low at the 1-, 2-, and 3-month follow-ups but were within the reliable range at 6 and 12 months after surgery. The rate of completion of tests A and B using the mobile app was significantly lower in the group older than 70 years than in the other groups for all postoperative periods (P CONCLUSIONS PROMs using mobile apps with different locations differed soon after surgery but were reliably similar after 6 months. The remote PROMs using mobile apps could be used reliably for the patient more than 6 months after surgery. However, it is to be expected that the use of mobile app–based questionnaires is not as useful in the group older than 70 years as in other age groups.

Establishing the hospital’s own standard operating procedures (SOPs) and team training including physicians and technologists reduces the error rate of dual-energy X-ray absorptiometry (DXA) measurement. In addition, when monitoring DXA images, it is necessary to check whether region of interest (ROI) and bone mapping are properly set as well as patient positioning. Physicians often experience poor quality DXA images, which affects osteoporosis treatment. The purpose of this study is to analyze the change in the error rate of DXA images after a multidisciplinary team training including physicians and technologists. Experienced physicians and DXA technologists formed a training team to establish SOPs for DXA measurement. The training team instructed the other related hospital personnel for a month. We set the criteria of measurement errors (9 items for the lumbar spine image and 8 items for the proximal femur image). With these criteria, a total of 637 images (320 images before training and 317 images after training) were analyzed to check the frequency and distribution of errors before and after training. The most common error when measuring the lumbar spine image before training was inadequate bone mapping (51.9%), and when measuring the proximal femur image was the incorrect area of the ROI of the femoral neck (37.2%). The most improved error after training was inadequate bone mapping (33.3% improvement) in the lumbar spine image and inadequate internal rotation (13.6% improvement) in the proximal femur image. Errors were significantly reduced by 23.2% in the lumbar spine, 9.0% in the proximal femur, and 9.2% in both the regions. Establishing SOPs and multidisciplinary team training effectively reduced the error rate of DXA images.

Background:Soft tissue laxity around the knee joint has been recognized as a crucial factor affecting correction error during medial open-wedge proximal tibial osteotomy (MOWPTO). Medial laxity in particular, which represents the changes in joint-line convergence angle (JLCA), affects soft tissue correction.Purpose:The purpose of this study was to quantify medial laxity and develop a preoperative planning method that considers medial laxity.Study Design:Cohort study; Level of evidence, 3.Methods:This study retrospectively reviewed 139 knees in 117 patients who underwent navigation-assisted MOWPTO from January 2014 to July 2019 for symptomatic medial compartment osteoarthritis with varus alignment >5°. We compared the results of 2 preoperative planning methods: conventional Miniaci (n = 47) and latent medial laxity reduction (LMLR) (n = 92). We evaluated the incidence of undercorrection, acceptable correction, and overcorrection. The radiologic parameters were analyzed using multiple linear regression with a stepwise selection model to establish an equation for the optimal preoperative planning method. The intraclass correlation coefficients (ICCs) of intraobserver, interobserver, and intermethod reliability were calculated.Results:The Miniaci method showed a higher incidence of overcorrection (55.3%) than the LMLR method (22.8%) at postoperative 6 months ( P = .0006). Multiple linear regression with a stepwise selection model revealed a high correlation coefficient ( R2= 0.888) for the following equation: Adjusted planned correction angle = 0.596 + 0.891 × Target correction angle – 0.255 × Δ JLCAvalgus. Upon simplification, the following equation showed the highest intermethod ICC value (0.991): Target correction angle – ⅓Δ JLCAvalgus, while the Miniaci method showed a relatively low ICC value of 0.875.Conclusion:There was a risk of overcorrection after MOWPTO using the conventional Miniaci method. An equation that considers medial laxity may help during preoperative planning for optimal correction during MOWPTO.

Injury of the medial head of the gastrocnemius, also called "tennis leg," is known to heal uneventfully in most cases with compression and immobilization therapy. Failure to heal or long-term complications, including ongoing pain and pes equinus, have been documented in only a limited number of case reports. To the best of our knowledge, a severe concomitant contracture of the knee and ankle joint as a consequence of a maltreated gastrocnemius muscle rupture has not been previously reported in English-language reports. The purpose of the present study was to report a serious complication of neglected tennis leg with a review of the published data.

Background To date, several trials have reported the use of mesenchymal stem cell (MSC) implantation for osteonecrosis of the femoral head (ONFH). However, the clinical outcomes have not been conclusive. This study compared the clinical and radiological results of bone marrow mesenchymal stem cell (BMMSC) implantation with traditional simple core decompression (CD) using a matched pair case–control design. Methods We retrospectively reviewed 100 patients with ONFH (106 hips) who had been treated by CD alone (50 patients, 53 hips) and CD + BMMSC implantation (50 patients, 53 hips) between February 2004 and October 2014. We assessed the total hip replacement arthroplasty (THA) conversion rate and ARCO (Association Research Circulation Osseous) stage progression. Survivor rate analysis was performed using the Kaplan–Meier method, and an additional THA was defined as the primary endpoints. Results The mean follow-up period was 4.28 years. There was a difference in the THA conversion rate between the CD (49%) and CD + BMMSC groups (28.3%) (p = 0.028). ARCO stage progression was noted in 20 of 53 hips (37.7%) in the CD group and 19 of 53 hips (35.8%) in the CD + BMMSC group. Among collapsed cases (ARCO stages III and IV), there was no difference in clinical failure rate between the two groups. Conversely, in the pre-collapse cases (ARCO stages I and II), only 6 of 30 hips (20%) progressed to clinical failure in the CD + BMMSC group, whereas 15 of 30 hips (50%) progressed to clinical failure in the CD group (p = 0.014). Kaplan–Meier survival analysis showed a significant difference in the time to failure between the two groups up to 10-year follow-up (log-rank test p = 0.031). There was no significant difference in terms of age (p = 0.87) and gender (p = 0.51) when comparing THA conversion rates between groups. No complication was noted. Conclusions These results suggest that implantation of MSCs into the femoral head at an early stage of ONFH lowers the THA conversion rate. However, ARCO stage progression is not affected by this treatment. Trial registration Retrospectively registered

Background: After posterior cruciate ligament injury, stress radiography is a common method of quantifying posterior instability, defined as the side-to-side difference in posterior tibial displacement (PTD) between the injured knee and contralateral noninjured knee. However, no study has evaluated the reliability of PTD according to knee flexion angle (KFA) measurements on stress radiographs. Purpose: To evaluate the test-retest reliability of stress radiographic measurements of the KFA in the noninjured knee. In addition, we established a reliable range of KFAs to indicate posterior instability by comparing results with the instability measured at 90° KFA, which is considered the gold standard. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: We evaluated patients who had undergone bilateral stress radiographic examinations at least 5 times for ligament injuries between January 2013 and November 2019. All examinations were performed on a Telos device with a 150-N posterior load. A total of 120 knees and 644 stress radiographs were enrolled. We measured the KFA and PTD on stress radiographs and evaluated the reliability of repeated PTD measurement and the correlation between KFA and PTD. Results: The distribution of the actual noninjured knee KFA ranged from 56.9° to 106.7°. Among the 644 radiographs, 155 (24.1%) showed KFAs between 85° and 95°, and 287 (44.6%) showed KFAs between 80° and 85°. A significant correlation was found between KFA and PTD ( P < .001), and the intrapatient intraclass correlation coefficient (ICC) was 0.788. A KFA range of 85° to 92° satisfied the criteria of high ICC (0.885) and nonsignificant correlation between KFA and PTD ( P = .055) and thus was considered a reliable range of KFAs for quantifying posterior instability. We found no significant risk factors for measurement error, including age ( P = .674), sex ( P = .328), height ( P = .957), weight ( P = .248), or body mass index ( P = .257). Conclusion: We found high reproducibility of posterior displacement measurements on Telos stress radiography at a KFA of 85° to 92° in noninjured knees.

Direct energy deposition (DED) technology has gained increasing attention as a new implant surface technology that replicates the porous structure of natural bones facilitating osteoblast colonization and bone ingrowth. However, concerns have arisen over osteolysis or chronic inflammation that could be caused by Cobalt-chrome (CoCr) alloy and Titanium (Ti) nanoparticles produced during the fabrication process. Here, we evaluated whether a DED Ti-coated on CoCr alloy could improve osteoblast colonization and osseointegration in vitro and in vivo without causing any significant side effects. Three types of implant CoCr surfaces (smooth, sand-blasted and DED Ti-coated) were tested and compared. Three cell proliferation markers and six inflammatory cytokine markers were measured using SaOS2 osteoblast cells. Subsequently, X-ray and bone histomorphometric analyses were performed after implantation into rabbit femur. There were no differences between the DED group and positive control in cytokine assays. However, in the 5-bromo-2&prime, deoxyuridine (BrdU) assay the DED group exhibited even higher values than the positive control. For bone histomorphometry, DED was significantly superior within the 1000 &micro, m bone area. The results suggest that DED Ti-coated metal printing does not affect the osteoblast viability or impair osseointegration in vitro and in vivo. Thus, this technology is biocompatible for coating the surfaces of cementless total knee arthroplasty (TKA) implants.

Because of the recent technological advances, the cementless total knee arthroplasty (TKA) implant showed satisfactory implant survival rate. Newly developed 3D printing direct energy deposition (DED) has superior resistance to abrasion as compared to traditional methods. However, there is still concern about the mechanical stability and the risk of osteolysis by the titanium (Ti) nanoparticles. Therefore, in this work, we investigated whether DED Ti-coated cobalt-chrome (CoCr) alloys induce chronic inflammation reactions through in vitro and in vivo models. We studied three types of implant surfaces (smooth, sand-blasted, and DED Ti-coated) to compare their inflammatory reaction. We conducted the in vitro effect of specimens using the cell counting kit-8 (CCK-8) assay and an inflammatory cytokine assay. Subsequently, in vivo analysis of the immune profiling, cytokine assay, and histomorphometric evaluation using C57BL/6 mice were performed. There were no significant differences in the CCK-8 assay, the cytokine assay, and the immune profiling assay. Moreover, there were no difference for semi-quantitative histomorphometry analysis at 4 and 8 weeks among the sham, smooth, and DED Ti-coated samples. These results suggest that DED Ti-coated printing technique do not induce chronic inflammation both in vitro and in vivo. It has biocompatibility for being used as a surface coating of TKA implant.

Biological repair of cartilage lesions remains a significant clinical challenge. A wide variety of methods involving mesenchymal stem cells (MSCs) have been introduced. Because of the limitation of the results, most of the treatment methods have not yet been approved by the Food and Drug Administration (FDA). However, bone marrow aspirate concentrate (BMAC) and human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) implantation were approved by Korea FDA. The aim of this study was to evaluate clinical and magnetic resonance imaging (MRI) outcomes after two different types of MSCs implantation in knee osteoarthritis. Fifty-two patients (52 knees) who underwent cartilage repair surgery using the BMAC (25 knees) and hUCB-MSCs (27 knees) were retrospectively evaluated for 2 years after surgery. Clinical outcomes were evaluated according to the score of visual analogue scale (VAS), the International Knee Documentation Committee (IKDC) subjective, and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Cartilage repair was assessed according to the modified Magnetic Resonance Observation of Cartilage Repair Tissue (M-MOCART) score and the International Cartilage Repair Society (ICRS) cartilage repair scoring system. At 2-year follow-up, clinical outcomes including VAS, IKDC, and KOOS significantly improved ( P < 0.05) in both groups; however, there were no differences between two groups. There was no significant difference in M-MOCART [1-year ( P = 0.261), 2-year ( P = 0.351)] and ICRS repair score ( P = 0.655) between two groups. Both groups showed satisfactory clinical and MRI outcomes. Implantation of MSCs from BMAC or hUCB-MSCs is safe and effective for repairing cartilage lesion. However, large cases and a well-controlled prospective design with long-term follow-up studies are needed.

Background Actinomycosis is a rare, chronic granulomatous disease caused by Gram-positive anaerobic bacteria that colonize the oral cavity. Cervicofacial actinomycosis is the most frequent clinical presentation of actinomycosis, but hematogenous osteomyelitis at distant sites can occur in rare instance in immunocompromised or pediatric patients, only a few cases have been reported in healthy patients. Here we described a new case of distal femur osteomyelitis caused by Actinomyces in an adult patient who was immunocompetent and had no predisposing factors. Case presentation A woman aged 52 years with no history of trauma presented with severe pain, swelling, and increased local heat in the proximal area of the right knee 3 weeks after she first noticed discomfort. Magnetic resonance imaging showed persistent osteomyelitis of the distal metaphysis and diaphysis of the femur with a multifocal intraosseous abscess pocket. An incision and drainage of the abscess were conducted. The tissue culture, fungus culture, acid fast bacillus (AFB) culture, AFB smear, and tuberculosis polymerase chain reaction test results were negative. A pathologic examination confirmed the presence of actinomycosis. The patient was successfully treated with intravenous penicillin G for 8 weeks followed by oral amoxicillin-clavulanate for 6 weeks with repeated surgical debridement and drainage. After a 5-year follow up, the patient had no signs of recurring infection or complications and she had full range of movement in the affected knee. Conclusions Although rare, actinomycotic osteomyelitis can occur in healthy people. Furthermore, actinomycotic osteomyelitis is easily misdiagnosed as tuberculosis in areas with a high prevalence of tuberculosis. To detect and identify the bacteria accurately, pathologic examination should be performed as well as culture tests, because the probability for culture confirmation of actinomycosis is quite low. The initial treatment is vital to a successful outcome without ostectomy or amputation.

The degradation of structural collagen contributes to the characteristic appearance of wrinkles. The anti-wrinkle effects of a variety of substances have been studied, but the potential anti-wrinkle effects of topical applications of collagen for periorbital wrinkles have not been investigated. To evaluate the effects of topical application of succinylated atelocollagen on periorbital wrinkles and to compare the results of treatment with adenosine, a clinical study on Korean participants was carried out. Each participant’s right or left periorbital area was treated with either a solution containing succinylated atelocollagen and adenosine or a solution containing only succinylated atelocollagen for two months. A placebo solution was applied to the opposite periorbital area of each patient’s face for two months. Based on objective and subjective measurements of clinical improvement, the assessment scores for treated sites were statistically significantly higher than scores for placebo sites after two months of treatment. Analysis of silicone casts of periorbital wrinkles demonstrated partial effects of succinylated atelocollagen on periorbital wrinkles. However, we did not observe any effects of adenosine on periorbital wrinkles. Succinylated atelocollagen may be an effective treatment option for periorbital wrinkles, but further studies including a longer treatment period and larger subject group are needed to verify these results.