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Revision hip arthroscopy is increasingly common and most often performed to treat residual femoroacetabular impingement caused by cam under-resection. Unfortunately, other pathologies encountered during revision hip arthroscopy are more difficult to treat, including capsular deficiency, labral deficiency, adhesion formation, and/or cam over-resection. When encountered, these various pathologies should be comprehensibly corrected with the goals of restoring anatomy, re-establishing the hip fluid seal, and ensuring impingement-free motion. Labral deficiency can successfully be treated with labral augmentation or reconstruction. Capsular deficiency is best managed with primary repair or capsular reconstruction. Cam over-resection is a difficult problem, but there is growing evidence for a soft-tissue remplissage used to fill the defect with soft tissue. The combination of these problems can be considered a salvage scenario but can be treated comprehensively with these techniques with improved outcomes and acceptable survivorship., Competing Interests: Disclosures The authors (J.J.R., A.N., N.A.F. and M.J.P.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background: The treatment of complex radial head fractures remains controversial with open reduction and internal fixation (ORIF), radial head arthroplasty, and radial head excision being the most common treatment options. While ORIF is the preferred treatment strategy for Mason type II fractures, the optimal treatment of Mason type III fractures is debated. The purpose of this study was to report minimum 10-year outcomes after ORIF of Mason type II and type III radial head fractures. We hypothesized that both Mason Type II and Type III fracture patients would demonstrate satisfactory clinical outcomes at minimum 10-year follow-up., Methods: All patients with Mason type II or III radial head fractures who were treated with ORIF by a single surgeon between 2005 and 2010 were included. Fractures with significant bone defects were treated with bone grafts and elbow ligament injuries were treated with either primary ligament repair or reconstruction. Patient reported outcome questionnaires were administered at the time of last clinical follow-up and at a minimum of 10 years postoperatively., Results: Twenty-four patients, including 13 male and 11 female patients with an average age of 39 (range 19-60) at the time of surgery met inclusion criteria. Thirteen patients suffered from Mason type II and 11 patients from Mason type III fractures. At initial follow-up, 21 out of 24 fractures (88%) demonstrated radiographic union. Three nonunions, 2 of which were Mason type III fractures, were treated with revision ORIF and iliac crest bone grafting. 11 patients developed postoperative elbow stiffness and required capsular release surgery. At last clinical follow-up, average flexion was 139°, average extension was 4°, average supination was 77°, and average pronation was 81°. The median Disabilities of the Arm, Shoulder and Hand score was 7 (ranging from 0 to 32). Minimum 10-year follow-up (mean: 14.6 years) was collected on 18 of 24 (75%) of the patients. At a minimum of 10 years postoperatively, the median QuickDASH score was 4.5 (range: 0 to 25) and the median SANE score was 96.5 (range: 75-100). Median satisfaction with the surgical outcome was 10 of 10 (range: 3-10)., Conclusion: ORIF of Mason type II and III radial head fractures results in high union rates with good functional outcomes at a mean of 14.6 years postoperatively. The study results suggest that ORIF of Mason type II and III radial head fractures leads to long-term positive functional outcomes., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The treatment of patients who suffer a proximal humeral fracture (PHF) remains controversial. The purpose of this study was to find consensus among experts using a validated iterative process in the treatment of patients after a PHF., Methods: The Neer Circle is an organization of shoulder experts recognized for their service to the American Shoulder and Elbow Surgeons. Consensus among 86 identified experts from this group was sought with a series of surveys using the Delphi process. The first three surveys included vignettes with 2-part, 3-part, and 4-part fractures, under two scenarios, (1) a healthy 55-year-old and (2) and a 75-year-old with significant medical comorbidities. Within each vignette, respondents were asked about their preference on CT utilization, and whether they would select operative or nonoperative treatment. A final survey was administered to elicit respondent preferences on general treatment approaches regardless of specific vignette characteristics., Results: Consensus was reached on the value of CT scans with 3D reconstructions, age as an important factor in determining treatment, functional demand, fracture pattern, bone quality, and the presence of more significant medical comorbidities would strongly impact decision making. Experts agreed that medial calcar involvement would have no impact on their decision, and gender and non-dominant arm involvement would have a low impact. Consensus was reached in the following scenarios for an operative treatment in a young and healthy patient: 2-part shaft fracture (V3, 98%); 3-part varus fracture (V5, 98%); 3-part valgus fracture (V7, 98%); 4-part fracture (V9, 100%); 4-part dislocation fracture (V11, 98%) and 4-part valgus impacted fractures (V13, 95%). For older unhealthy patients in 4- part dislocation fractures (V12, 100%). In the remainder of scenarios, there was no consensus reached for preferred treatment, either operative or nonoperative. Finally, there was no consensus on preferred rehab protocols, whether for nonoperative management or postoperative care., Conclusion: In conclusion, this study demonstrates that consensus when managing proximal humerus fractures is limited to specific scenarios, while lack of consensus still exists in others. The presented study advocates non-operative treatment of proximal humerus fractures in the sicker patient and surgical treatment methods for 3-part and 4-part fractures in the young, healthy patient., (Copyright © 2025. Published by Elsevier Inc.)

Background: There is growing evidence that medial meniscotibial ligament (MTL) deficiency and medial meniscus extrusion may precede the development of some medial meniscus posterior root (MMPR) tears. However, no study has investigated the biomechanical consequences of MTL deficiency on the MMPR., Hypothesis: (1) MTL deficiency leads to increased medial meniscus extrusion, (2) increased medial meniscus extrusion is correlated with increased compression and shear forces at the MMPR, and (3) MTL repair restores medial meniscus extrusion and MMPR forces to native levels., Study Design: Controlled laboratory study., Methods: Fifteen pairs of fresh-frozen cadaveric knees were tested. Specimens were organized into 3 groups according to a balanced incomplete block design: (1) native, (2) MTL deficiency, and (3) MTL repair. For the MTL deficiency group, a 3-cm deficiency in the MTL was developed under direct arthroscopic visualization. Specimens in the MTL repair group underwent a 2-anchor repair that compressed the joint capsule to the proximal tibia. All specimens were biomechanically tested in full extension with a tensile testing machine. The specimens underwent cyclic loading for 10,000 cycles at 1 Hz and compression of 20 to 500 N, with a 500-N compressive force applied for 30 seconds after the 0th, 100th, 1000th, and 10,000th cycles. Ultrasound was used to measure medial meniscus extrusion. Shear and compressive forces at the MMPR were measured with a 3-axis sensor installed inferior to the MMPR tibial attachment., Results: Medial meniscus extrusion was significantly increased in the MTL deficiency group compared with the native group (0th: 1.6 ± 0.1 mm vs 1.2 ± 0.1 mm, P < .05; 100th: 2.2 ± 0.2 mm vs 1.5 ± 0.2 mm, P < .05; 1000th: 2.8 ± 0.2 mm vs 1.8 ± 0.2 mm, P < .05; 10,000th: 3.5 ± 0.3 mm vs 2.1 ± 0.2 mm, P < .05). Compression root force was significantly increased in the MTL deficiency group compared with the native group at all cyclic loading points (0th: 21.7 ± 12.8 N vs 13.6 ± 2.4 N, P < .05; 100th: 18.9 ± 11.0 N vs 12.1 ± 7.5 N, P < .05; 1000th: 16.5 ± 9.9 N vs 11.2 ± 7.5 N, P < .05; 10,000th: 12.6 ± 8.6 N vs 9.0 ± 6.9 N, P < .05). Root shear force was significantly increased in the MTL deficiency group compared with the native group at the 0th (17.5 ± 2.5 N vs 13.6 ± 2.4 N, P < .001) and 100th (16.2 ± 2.6 N vs 12.1 ± 2.2 N, P < .001) cycles. Medial meniscus extrusion, root shear force, and compression root force of the MTL repair group were not significantly different from the native group for all cyclic loading points., Conclusion: Medial MTL deficiency led to increased medial meniscus extrusion as well as greater compression and shear forces at the MMPR compared with the intact and repaired MTL states, suggesting that MTL deficiency may predispose the MMPR to injury in a cadaveric model., Clinical Relevance: MTL deficiency predisposes one to medial meniscus extrusion and MMPR tears. Subsequently, MTL repair can potentially correct medial meniscus extrusion and normalize forces at the MMPR., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A.F.V. has received consulting fees from Arthrex Inc and Stryker, honoraria from Vericel Corp, speaking fees from Smith & Nephew, hospitality payments from BodyCAD USA, and support for education from Gemini Mountain Medical. M.T.P. has received royalties from Arthrex Inc, Arthrosurface, Responsive Arthroscopy, and Anika Therapeutics Inc; consulting fees from Arthrex Inc, Joint Restoration Foundation (JRF), Zimmer Biomet Holdings, and Arthrosurface; grants from the Department of Defense (DoD), National Institutes of Health (NIH), and DJO; and honoria from Flexion Therapeutics. M.J.J.A. has received grants from Arthrex and DJO, support for education from Smith & Nephew, and hospitality payments from Medical Device Business Services. E.A.W. has received grants from DJO and support for education from Smith & Nephew. J.M.A. has received grants from Arthrex, hospitality payments from Arthrex, and support for education from Smith & Nephew and Stryker 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: The number of meniscal repairs being completed each year is increasing; however, the optimal, cost-effective postoperative assessment to determine the success or failure of a meniscal repair is not well known., Purpose/hypothesis: The purpose of this systematic review was to identify the clinical examination testing that correlates with objective magnetic resonance imaging (MRI) or second-look arthroscopy (SLA) findings to determine an optimal clinical workup for assessing postoperative meniscal repair healing. It was hypothesized that specific clinical tests would correlate with meniscal repairs that did not heal., Study Design: Systematic review and meta-analysis; Level of evidence, 4., Methods: This systematic review included all clinical studies investigating meniscal repairs, meniscal repair outcomes, and meniscal healing with clinical findings, MRI, and/or SLA, published in a peer-reviewed journal and with full English text available. All included studies were evaluated for bias using the Methodological Index for Non-Randomized Studies (MINORS). The clinical tests included those using "Barrett's criteria," with the assessment of effusion, joint line tenderness, locking, McMurray testing, and radiographs. This parameter has also been abbreviated to "modified Barrett's criteria" to include only joint line tenderness, effusion, and McMurray testing., Results: No significant correlations were found between clinical tests and MRI or SLA. A subgroup meta-analysis between Barrett's and non-Barrett's studies reported no significant subgroup differences (χ 1 2 = 0.24; P = .62). A meta-analysis of diagnostic accuracy using a group of 7 studies that reported on true-positive, true-negative, false-positive, and false-negative data for SLA demonstrated that only a lack of joint line tenderness had a high specificity for a healed meniscal repair, with a log diagnostic odds ratio of 2.62 (95% CI, 0.47-4.76)., Conclusion: This study found no significant correlation with any specific clinical test for meniscal repair healing status using postoperative MRI and/or SLA findings. However, it was found that no healing (when compared with complete or incomplete healing) on MRI and joint line tenderness should be considered when assessing the status of postoperative meniscal repair healing. In addition, a subgroup meta-analysis found that a lack of joint line tenderness was highly correlated with a healed meniscal repair., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: N.I.K. has received consulting fees from Vericel, research support from Arthrex, support for education from Foundation Medical and Smith & Nephew, and hospitality payments from Encore Medical and Zimmer Biomet Holdings. R.F.L. has received consulting fees from Ossur, Smith & Nephew, and Responsive Arthroscopy; royalties from Ossur, Smith & Nephew, Elsevier, and Arthrex; research support from Ossur and Smith & Nephew; and support for education from Foundation Medical. 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: Activity level is a benchmark to document patient recovery; however, there is a lack of instrumentation to measure activity level specific to the foot and ankle. The purpose of this study was to develop a foot and ankle activity level scale (FAALS) instrument that will serve as an effective clinical tool for practitioners by assigning an activity level to patients., Methods: This was a 4-phase study with 3 rounds of data collection (n = 1432). Phase 1 was item generation using an expert panel to determine content validity (101 items). In phase 2, all items from phase 1 were piloted (n = 100) to remove poorly performing items (77 items). In phase 3 (n = 505), item reduction, reliability, and validity Rasch analyses were conducted, leaving a total of 22 items. Validity was assessed using outfit mean-square (MNSQ) and infit MNSQ statistics, with acceptable values between 0.5 and 1.5. An additional round of data collection was completed to serve as a validation data set to confirm FAALS instrument structure and psychometric analytics (n = 827). Correlation analysis was performed to assess convergent and divergent validity. Multiple linear regression analysis was conducted to determine whether the FAALS could detect differences in scores between groups with previously proven factors that affect functional status., Results: Person reliability was 0.92 and item reliability was 1.00, demonstrating excellent reliability. There was excellent evidence of validity, with mean-square values between 0.5 and 1.5. The 22 FAALS items are summed for a total score that corresponds to one of 4 activity levels. The FAALS instrument demonstrated sensitivity in the ability to discern between groups with expected foot and ankle functional differences for previous ankle surgery status, t (502) = -7.69, P  < .001, and body mass index, t (502) = -3.41, P  < .001., Conclusion: The FAALS instrument is a short, clinically useful tool to measure activity level specific to the foot and ankle. FAALS normative values provide valuable information for physician-patient communication, which may serve to facilitate shared decision-making, improve postoperative care, and allow physicians to track recovery progress., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Thomas O. Clanton, MD, reports disclosures relevant to study from Arthrex, Inc: IP royalties, paid consultant, paid presenter or speaker, research support; BICMD: paid consultant; Gemini Mountain Medical, Inc: research support; Gentleman Orthopedics, Inc: research support; Stryker: IP royalties, paid consultant, paid presenter or speaker, research support; SubioMed, Inc: paid consultant, stock or stock options; Wright Medical Technology, Inc: research support and general disclosures from Foot & Ankle International: editorial or governing board. Jonathon D. Backus, MD, reports disclosures relevant to study from Marrow Access Technologies: stock or stock options; Medline UNITE: IP royalties, paid consultant, and general disclosures; American Orthopaedic Foot & Ankle Society: board or committee member; and Foot & Ankle International: editorial or governing board. Norman E. Waldrop III, MD, reports disclosures relevant to study from Arthrex, Inc: IP royalties, paid consultant, paid presenter or speaker; and J&J: IP royalties, paid presenter or speaker. Marilee P. Horan, MPH, reports disclosures relevant to study from position supported by the Steadman Philippon Research Institute (which is a 501(c)(3) non-profit institution supported financially by private donations and corporate support; during the past calendar year, SPRI has received grant funding or in-kind donations from Arthrex, Canon, DJO, Icarus Medical, Medtronic, Ossur, Smith+Nephew, SubioMed, Stryker and Wright Medical). Anastasia Robinson, PT, DPT, OCS, reports disclosures relevant to study from Arthrex, Inc: paid presenter or speaker. Disclosure forms for all authors are available online.

Duchenne muscular dystrophy (DMD) is a severe genetic muscle disease occurring due to mutations of the dystrophin gene. There is no cure for DMD. Using a dystrophin -/- utrophin -/- (DKO-Hom) mouse model, we investigated the PGE2/EP2 pathway in the pathogenesis of dystrophic muscle and its potential as a therapeutic target. We found that Ep2, Ep4, Cox-2, 15-Pgdh mRNA, and PGE2 were significantly increased in DKO-Hom mice compared to wild-type (WT) mice. The EP2 and EP4 receptors were mainly expressed in CD68 + macrophages and were significantly increased in the muscle tissues of both dystrophin -/- (mdx) and DKO-Hom mice compared to WT mice. Osteogenic and osteoclastogenic gene expression in skeletal muscle also increased in DKO-Hom mice, which correlates with severe muscle heterotopic ossification (HO). Treatment of DKO-Hom mice with the EP2 antagonist PF04418948 for 2 weeks increased body weight and reduced HO and muscle pathology by decreasing both total macrophages (CD68 + ) and senescent macrophages (CD68 + P21 + ), while increasing endothelial cells (CD31 + ). PF04418948 also increased bone volume/total volume (BV/TV), the trabecular thickness (Tb.Th) of the tibia trabecular bone, and the cortical bone thickness of both the femur and tibia without affecting spine trabecular bone microarchitecture. In summary, our results indicate that targeting EP2 improves muscle pathology and improves bone mass in DKO mice.

Background: Previous research has reported higher rates of both injury and illness among Paralympic athletes compared with Olympic athletes during the Winter Olympic and Paralympic Games, but no studies have directly compared injury and illness incidence between Olympic and Paralympic athletes competing in a Summer Games., Purpose: To compare injury and illness rates between Olympic and Paralympic Team USA athletes competing in the Tokyo 2020 Olympic and Paralympic Games., Study Design: Descriptive epidemiology study., Methods: All injuries and illnesses that occurred among the Team USA athletes competing in the Tokyo 2020 Summer Olympic or Paralympic Games were documented. A total of 701 Team USA athletes (53.6% female) competed in the Tokyo 2020 Summer Olympic Games, across 34 different sports. For the Tokyo 2020 Summer Paralympic Games, a total of 245 athletes (51.6% female) competed across 20 sports. Incidence rates (IRs) per 1000 athlete-days were calculated according to sex, sport, anatomic location, and illness type. IR ratios (IRRs) were calculated to compare IRs between male and female athletes and between Olympic and Paralympic athletes., Results: Overall, there were no differences in injury incidence (IRR, 1.18; 95% CI, 0.84-1.68) or illness incidence (IRR, 0.68; 95% CI, 0.41-1.15) between Olympic and Paralympic athletes. Male Paralympic athletes were less likely to sustain an illness compared with female Paralympic athletes (IRR, 0.35; 95% CI, 0.11-0.90)., Conclusion: There were no differences in injury or illness rates between Olympic and Paralympic Team USA athletes competing at the Tokyo 2020 Summer Games, contrary to previous comparisons among winter sport athletes. These results challenge the prevailing notion that Summer Paralympic athletes are at greater injury and illness risk, suggesting that factors beyond Olympic or Paralympic Games participation influence health concerns., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This study was funded in part by a research center grant from the International Olympic Committee. J.T.F. has received consulting fees from Sanofi-Aventis US. 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., (© The Author(s) 2025.)

Background: Sternoclavicular joint (SCJ) instability can lead to pain, reduced function, and an inability to perform sports and activities of daily living. Reconstruction of the SCJ using hamstring autograft in a figure-of-8 configuration has demonstrated good outcomes at short- and midterm follow-ups, but there is a paucity of literature on long-term outcomes., Purpose: To evaluate the long-term clinical and functional outcomes after SCJ reconstruction, with a focus on return to sport, instability recurrence, and revision surgery., Study Design: Case series; Level of evidence, 4., Methods: Patients who underwent SCJ reconstruction with a hamstring autograft for the treatment of SCJ instability between December 2010 and June 2013 by a single surgeon with a minimum 10-year follow-up were eligible for inclusion. Patient-reported outcome measures, including the American Shoulder and Elbow Surgeons (ASES) Score, short version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire, Single Assessment Numeric Evaluation (SANE), visual analog scale (VAS) for pain, and patient satisfaction (1-10 scale, with 10 indicating maximum satisfaction), rates of return to sport, instability recurrence, and revision surgery, were evaluated at short- (2-3 years), mid- (5-8 years), and long-term (minimum 10 years) follow-ups., Results: Eleven patients (13 shoulders) were evaluated at a median of 10.0 years (IQR, 10.0-11.0 years) postoperatively. SCJ instability was chronic in 12 shoulders (92.3%) and acute in 1 shoulder (7.7%). One shoulder underwent revision SCJ reconstruction and was excluded from further analysis (survivorship: 92.3%). Significant pre- to postoperative improvements in shoulder function and pain were observed at short-term follow-up and were either maintained or further improved at mid- and long-term follow-ups. At a minimum of 10 years postoperatively, shoulder function (median ASES score: 95.0 [IQR, 86.2-97.5]; median QuickDASH: 12.5 [IQR, 6.8-15.9]; median SANE: 89.0 [IQR, 81.5-96.3]) was excellent, pain levels were low (median VAS for pain: 0.5 [IQR, 0-1.8]), and patient satisfaction was high (median, 9.0 [IQR, 8.0-10]). All patients returned to sport (n = 10; 100%) at levels equal to or above (n = 3; 30.0%) or slightly below (n = 7; 70.0%) their preinjury level. Two of these patients (20.0%) reported instability-related modifications in activity. One patient had recurrent instability 2.5 years postoperatively but had excellent shoulder function at the final follow-up. The overall rate of instability recurrence was 36.4% (4/11 patients)., Conclusion: SCJ reconstruction using a hamstring autograft for the treatment of SCJ instability resulted in significant improvements in shoulder function, low levels of pain, and high return-to-sport rates at long-term follow-up. Revision surgery rates were low., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: M.H., C.D., M.P.H., and A.D. report that their positions are supported by the Steadman Philippon Research Institute, which is a 501(c)(3) nonprofit institution supported by private donations and corporate funding. The Steadman Philippon Research Institute (SPRI) exercises special care to identify any financial interests or relationships related to research conducted here. During the past calendar year, SPRI has received grant funding or in-kind donations from Arthrex, Canon, DJO, Icarus Medical, Medtronic, Ossur, Smith+Nephew, SubioMed, Stryker, and Wright Medical. M.H. has received support for education from Arthrex. D.K. has received support for education from Smith+Nephew, Fortis Surgical, and Arthrex. M.T.P. is an editorial board or governing board member for SLACK Inc; a board or committee member for AANA, AAOS, AOSSM, ASES, SDSI, and SOMOS; and declares royalties from Arthrex Inc, Arthrosurface, Responsive Arthroscopy, and Anika Therapeutics Inc; consulting fees from Arthrex Inc, Joint Restoration Foundation (JRF), Zimmer Biomet Holdings, and Arthrosurface; grants from the Department of Defense (DoD), National Institutes of Health (NIH), and DJO; and honoraria from Flexion Therapeutics. P.J.M. has received IP royalties, consulting fees, and research support from Arthrex; research support from Ossur, Siemens, and Smith+Nephew; and publishing royalties and financial or material support from Springer; and holds stock or stock options in VuMedi. 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 concept of on-track versus off-track bone lesions in glenohumeral instability continues to evolve. Although much has been ascertained from an original biomechanical model, bony pathological changes, especially on 3-dimensional (3D) imaging, have not been fully evaluated., Purpose: To compare the differences in on-track versus off-track lesions to characterize glenoid and humeral head bone defects using 3D modeling software., Study Design: Cross-sectional study; Level of evidence, 3., Methods: A consecutive cohort of 75 patients with recurrent anterior instability, with evidence of Hill-Sachs lesions (HSLs) and glenoid bone loss (GBL) and a mean age of 27.1 years (range, 18-48 years), were reviewed. 3D models of unilateral proximal humeri and glenoids were reconstructed. The volume, surface area, width, and depth of identified HSLs were quantified, along with their location (medial, superior) and orientation (Hill-Sachs angle). The percentage, width, and length of GBL as well as the glenoid track status were calculated. The on-track and off-track groups were compared using the Mann-Whitney U test., Results: The off-track group had greater HSL surface area (374.23 vs 272.64 mm 2 , respectively; P = .001), more HSL medialization (14.96 vs 17.62 mm, respectively; P = .028), greater HSL volume (603.08 vs 433.61 mm 3 , respectively; P = .007), and a greater mean HSL width (16.06 vs 11.53 mm, respectively; P = .001) than the on-track group. The off-track group also had greater GBL (22.55% vs 17.73%, respectively; P = .037), a greater GBL width (6.92 vs 3.58 mm, respectively; P < .001), and a greater GBL length (21.61 vs 16.1mm, respectively; P = .015) than the on-track group. Further analysis of large off-track lesions revealed a greater Hill-Sachs angle (33.16° vs 26.20°, respectively; P = .035) and a more superior extent of HSLs compared with borderline off-track and on-track lesions., Conclusion: Off-track lesions were found to have larger GBL, a larger HSL width, a more medialized HSL, and greater HSL surface area. This study outlines the specific characteristics of high-risk bipolar bone loss lesions to simplify the identification of patients in a clinical setting and aid in appropriate treatment planning., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: J.W.A. has received hospitality payments from Arthrex, Mid-Atlantic Surgical Systems, and Smith+Nephew; education payments from Mid-Atlantic Surgical Systems; and grants from Arthrex and DJO. C.B.R. has received grants from Arthrex and DJO and education payments from Smith+Nephew and MedInc of Texas. M.T.P. has received royalties from Anika Therapeutics, Arthrex, and Arthrosurface; consulting fees from Arthrex, Zimmer Biomet, and JRF Ortho; nonconsulting fees from Arthrex and Arthrosurface; education payments from Arthrex; and honoraria from Flexion Therapeutics and JRF Ortho. 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., (© The Author(s) 2024.)

Background: A labral injury contributes to glenohumeral instability. The Anterior Labral Circumferential Onlay Technique (ALCOT) reconstructs the labrum using the long head of the biceps tendon., Hypothesis: The ALCOT would restore glenohumeral joint stability in a cadaveric model without glenoid bone loss (1) comparable to the native state and (2) comparable to the Latarjet procedure., Study Design: Controlled laboratory study., Methods: A total of 10 fresh-frozen cadaveric shoulders were tested using a 6 degrees of freedom robotic arm in 5 consecutive states: (1) native, (2) capsular repair, (3) labral tear, (4) ALCOT, and (5) Latarjet procedure. Biomechanical testing consisted of 80 N of anteroinferior force and 50 N of compression in 90° of humerothoracic abduction. Lateral displacement of the humeral head and the force ratio during a dislocation were measured., Results: The mean lateral translation of the humeral head during a dislocation in the native state was 6.5 ± 2.2 mm and decreased to 5.4 ± 2.4 mm in the labral tear state ( P < .001). The mean lateral translation of the humeral head was restored to 6.4 ± 2.2 mm ( P > .99) with the ALCOT, showing no difference from the native state. The Latarjet procedure restored the mean force ratio during a dislocation to 1.3 ± 0.6 but failed to restore lateral translation, with a value of 5.6 ± 2.8 mm ( P = .003 vs native; P = .94 vs labral tear). The mean force ratio was 1.8 ± 0.1 in the native state, decreased to 1.1 ± 0.4 in the labral tear state, and was 1.4 ± 0.4 ( P < .27) with the ALCOT, showing no difference from the native state., Conclusion: The ALCOT is a novel technique for labral reconstruction that may have a role in the treatment of anterior glenohumeral instability in the setting of a deficient labrum without bone loss. In this study, the ALCOT restored the force ratio and lateral translation of the humeral head compared to the native state. The Latarjet procedure restored the force ratio but not lateral translation of the humeral head compared to the native state., Clinical Relevance: This study proposes and biomechanically validates the ALCOT as a surgical technique for labral reconstruction that may have a role in treating patients with chronic anterior shoulder instability in the setting of a deficient labrum., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This study received partial support from Arthrex for in-kind products supplied. P.J.M. has received a royalty or license from Arthrex, consulting fees from Arthrex, and nonconsulting fees 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., (© The Author(s) 2024.)

Background: Patients with pre-existing neurologic disorders present a unique set of challenges for shoulder arthroplasty (SA) surgeons due to the presence of concomitant contractures, muscle weakness, and spasticity, which may affect outcomes and complication rates after SA. The goal of this systematic review was to evaluate the clinical and functional outcomes after SA in patients pre-existing with neurologic disorders, focusing on complication and reoperation rates., Methods: This systematic review was performed in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines outlined by Cochrane Collaboration. A search of PubMed, the Medline Library, and EMBASE from inception until September 2023 was conducted to obtain studies reporting on outcomes after SA in patients with neurologic disorders. Study demographics and information on outcomes including patient-reported outcomes and complication rates were collected. The methodological quality of included primary studies was appraised using the Methodological Index for Nonrandomized Studies scoring system., Results: Twenty articles published between 1997 and 2023 met inclusion criteria. In total, 13,126 patients with neurologic conditions with 7 different neurologic disorders (Parkinson's disease, epilepsy and seizures, cerebral palsy, poliomyelitis, Charcot neuropathy, cerebrovascular disease, and multiple sclerosis) were included. The mean patient age was 64.3 years (range, 33.0-75.8 years), 51.4% of patients were male, and the mean postoperative follow-up time was 5.1 years (range, 1.4-9.9 years). Parkinson's disease was the most reported neurologic disorder (9 studies, 8033 patients), followed by epilepsy (4 studies, 3783 patients), and multiple sclerosis (1 study, 1077 patients). While these patients did experience improvements in outcomes following SA, high complication and revision rates were noted., Conclusions: Patients with neurologic disorders demonstrate improvements in pain and function after SA but have higher reported complication and revision rates when compared with patients without neurologic conditions. This systematic review offers valuable data for both the surgeon and patient regarding anticipated clinical results and possible complications from SA in patients with neurologic disorders that may aid in shared decision-making when considering SA., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Microfracture is one surgical treatment strategy for osteochondral lesions of the talus (OLTs) but results in fibrocartilage repair tissue, which has inferior mechanical properties to native hyaline cartilage. Biological regulation of microfracture has been suggested to improve the quality of cartilage repair in patients., Purpose: To determine if administration of losartan, fisetin, or losartan and fisetin combined can enhance microfracture-mediated cartilage repair of OLTs in a rabbit model., Study Design: Controlled laboratory study., Methods: Four-month-old female rabbits were divided into the following groups (8 rabbits per group): microfracture only (microfracture), microfracture plus losartan (losartan), microfracture plus fisetin (fisetin), and microfracture plus losartan and fisetin (losartan+fisetin). A 2.7-mm osteochondral defect and 4 microfracture holes were created in the talar dome cartilage. The rabbits were administered losartan (10 mg/kg/day), fisetin (20 mg/kg/day), or losartan and fisetin orally until euthanized 12 weeks after surgery. Gross evaluation, micro-computed tomography, histology, and immunohistochemistry evaluations of the osteochondral defects were performed as well as quantitative polymerase chain reaction of capsule tissue and enzyme-linked immunosorbent assay of serum., Results: The losartan and fisetin groups had increased International Cartilage Regeneration & Joint Preservation Society macroscopic scores with improved cartilage repair and enhanced subchondral bone healing compared with the microfracture group. However, the losartan+fisetin group did not show a synergistic effect. O'Driscoll histology scores were higher in the losartan and fisetin groups compared with the microfracture group, while the losartan+fisetin group had a lower score than the losartan, fisetin, and microfracture groups. Collagen type 2 staining revealed organized chondrocytes in the losartan and fisetin groups, but the losartan+fisetin group did not show improvement when compared with other groups. Fisetin treatment decreased catalase and transforming growth factor-β1-activated kinase 1 expression in capsular tissue., Conclusion: Concomitant microfracture and biological regulation, using oral administration of either losartan or fisetin, may improve cartilage healing of OLTs; however, losartan and fisetin combined in the current drug administration regimen does not appear to provide synergistic effects., Clinical Relevance: Oral intake of losartan or fisetin may result in beneficial effects on microfracture-mediated cartilage repair of OLTs., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This project was funded by a philanthropy gift from the Smead/Byram family. The position of I.K.S. at the Steadman Philippon Research Institute was partially supported by Arthrex. M.J.P has received consulting fees and royalties from Smith & Nephew; royalties and support for education from Linvatec Corporation; research support from Arthrex; speaking fees from Synthes GMBH; and hospitality payments from Siemens Medical Solutions USA. T.O.C. has received consulting fees and royalties from Arthrex and Stryker; holds stock in BICMD; and has received support for education from Gemini Mountain and Wright Medical. J.H. has received royalty payment from Cook Myosite. J.J.R. has received consulting fees from Smith & Nephew and a 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.

Objective: To prospectively evaluate a deep learning-based denoising reconstruction (DLR) for improved resolution and image quality in musculoskeletal (MSK) magnetic resonance imaging (MRI)., Methods: Images from 137 contrast-weighted sequences in 40 MSK patients were evaluated. Each sequence was performed twice, first with the routine parameters and reconstructed with a routine reconstruction filter (REF), then with higher resolution and reconstructed with DLR, and with three conventional reconstruction filters (NL2, GA43, GA53). The five reconstructions (REF, DLR, NL2, GA43, and GA53) were de-identified, randomized, and blindly reviewed by three MSK radiologists using eight scoring criteria and a forced ranking. Quantitative SNR, CNR, and structure's full width at half maximum (FWHM) for resolution assessment were measured and compared. To account for repeated measures, Generalized Estimating Equations (GEE) with Bonferroni adjustment was used to compare the reader's scores, SNR, CNR, and FWHM between DLR vs. NL2, GA43, GA53, and REF., Results: Compared to the routine REF images, the resolution was improved by 47.61% with DLR from 0.39 ± 0.15 mm 2 to 0.20 ± 0.06 mm 2 (p < 0.001). Per-sequence average scan time was shortened by 7.93% with DLR from 165.58 ± 21.86 s to 152.45 ± 25.65 s (p < 0.001). Based on the average scores, DLR images were rated significantly higher in all image quality criteria and the forced ranking (p < 0.001)., Conclusion: This prospective clinical evaluation demonstrated that DLR allows approximately two times finer resolution and improved image quality compared to the standard-of-care images., (© 2024. The Author(s), under exclusive licence to International Skeletal Society (ISS).)

Background: The utilization of lateral extra-articular tenodesis (LET) augmentation for anterior cruciate ligament reconstruction has increased. Various fixation points have been recommended based on tactile and anatomic landmarks; however, there is limited reporting of the accuracy or precision of these techniques in clinical practice., Purpose/hypothesis: The purpose of this study was to evaluate whether LET fixation points identified using anatomic landmarks and tactile techniques would fall within a predefined radiographic zone. It was hypothesized that the majority of LET fixation points would be inside the radiographic zone., Study Design: Cross-sectional study; Level of evidence, 4., Methods: Postoperative lateral knee radiographs of patients who underwent anterior cruciate ligament reconstruction with LET using a landmark-based technique without fluoroscopy between January 2018 and September 2023 were reviewed. Fixation points were measured by 2 raters based on their distance from an extension of the posterior femoral cortex line (PFCL) distally and a line perpendicular to the PFCL at the posterior condylar flare (PCF). Patients were excluded if the tunnel position could not be identified or if postoperative radiographs were malrotated. The mean LET position and percentage of points within the radiographic isometric zone, defined as 4 ± 4 mm posterior and 4 ± 3 mm anterior to the PFCL and 6 ± 4 mm distal and 20 ± 5 mm proximal to the PCF were calculated., Results: Complete data sets were obtained for 47 cases. The mean LET position was 6.4 ± 7.1 mm (range, -9 to 27.3 mm) anterior to the PFCL and 1.8 ± 7.6 mm (range, -16.7 to 12.6 mm) proximal to the PCF. Overall, 53% of LET fixation points were within the predefined radiographic zone. Of the malpositioned tunnels (n = 22), their locations relative to the radiographic zone were anterior (n = 18), posterior (n = 2), proximal (n = 1), and anterior and distal (n = 1)., Conclusion: This study found large variation in the location of LET fixation points, and almost half of fixation points were outside the predefined radiographic zone. Accurate and precise tunnel placement is one of multiple factors that may be important to minimize the risk of lateral compartment overconstraint, anterior cruciate ligament graft failure, and anisometry leading to LET graft loosening., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: Steadman Philippon Research Institute has received grant funding or in-kind donations from Arthrex, DJO, MLB, Ossur, Siemens, Smith & Nephew, and XTRE. T.R.H. has received consulting fees and research support from Arthrex Inc and owns stocks or stock options in NICE. J.A.G. has received consulting fees from Bioventus, Smith & Nephew, DePuy Synthes Products, and Mitek; owns stock or stock options in Nice Recovery Systems; has received support for education from Gemini Mountain Medical and Arthrex; and has received hospitality payments from Medical Device Business Services. A.F.V. has received research support and consulting fees from Arthrex Inc; IP royalties and consulting fees from Stryker; speaking fees from Vericel and Smith & Nephew; hospitality payments from Bodycad USA; and support for education from Gemini Mountain Medical. A.C.K. has received support for education from Suvon Surgical. M.E.C. has received support for education from Evolution Surgical and hospitality payments from Stryker. 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.

Summary of Background Data: Iatrogenic injury of the vertebral artery (VA) in the context of surgical approaches to the cervical spine has been cited as a relatively rare complication with varying degrees of severity ranging from minimal injury to acute stroke and can result in death. It is estimated that ~50% of cases of iatrogenic VA injury are preventable after postoperatively examining a patient's preoperative imaging. Despite the low incidence (<2%) of this complication, the potential associated morbidity demonstrates the importance of meticulous preoperative vascular consideration., Objective: This study aims to emphasize the importance of preoperative vascular screening during anterior cervical access planning visualized through a rare case of a VA aberration in a 47-year-old patient., Study Design: This study is designed as a retrospective case report., Methods: A thorough chart review was performed for this subject including all prior medical records, imaging studies, imaging reports, operative notes, and communication records., Results: The subject was found to have a history of patent foramen ovale (PFO) repair with a rare vertebral artery malformation described as a medial transposition of the vertebral artery out of the vertebral artery foramen between C3 and C4., Conclusions: Consideration of cervical anatomy, particularly the VA, is key to minimizing the risk of adverse surgical outcomes in both anterior and posterior approaches to the cervical spine. During the workup process, the patient's primary care providers, radiologists, and surgeons should be aware of the potential variations of the VA with particular attention given to the course of the VA on MR imaging., Level of Evidence: Level IV., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The superior labrum and biceps complex is commonly implicated in shoulder pain and there remains discordance regarding the surgical management of superior labrum anterior to posterior (SLAP) tears. The purpose of this study was to establish an expert consensus regarding the management of superior labrum and biceps complex pathology., Methods: The NEER Circle is an organization of shoulder experts recognized for their service to the American Shoulder and Elbow Surgeons (ASES) society. Consensus among 92 identified experts was sought with a series of surveys pertaining to the management of superior labrum and biceps complex (SBC) pathology. The initial survey featured questions crafted to determine the experience of the panel in treating SBC pathology. The second survey was designed to elicit opinions concerning the diagnosis and treatment of SBC pathology. The third survey aimed to establish consensus across 48 scenarios, tasking panelists with categorizing four surgical modalities as either preferred, acceptable, or not acceptable. The available options included débridement, SLAP repair, biceps treatment, or a combined repair and biceps treatment. In the final survey, the panelists were tasked with diagnosing SBC pathologies by assessing arthroscopic footage and evaluating treatment options within 45 scenarios. A minimum of 80% agreement was required to attain consensus, designating a treatment as either preferred or unacceptable., Results: Response rates ranged from 52.2- 58.7%. Discordance exists regarding aspects of the physical examination, patient history, imaging, non-operative management, and the surgical approach in SBC injuries. Of the 78 clinical scenarios, 26 reached consensus agreement. Treating the biceps was the favored approach in older, more sedentary patients with evidence of biceps tendinopathy. Performing a SLAP repair was favored in scenarios depicting younger, more active patients with signs of an unstable biceps anchor or mechanical symptoms. A SLAP repair was typically contraindicated in the setting of an older patient, concomitant rotator cuff tear and/or a prior failed SLAP repair. The management of overhead throwing athletes, particularly those that are professionals, remained controversial, although SLAP repair is generally favored in younger pitchers., Conclusion: The optimal management of superior labrum and biceps complex pathology requires a systematic approach based on the individual's age, occupational demands and functional requirements. Age was the predominant factor influencing surgical decision making. SLAP repairs are generally favored in younger, active patients while treating the biceps is preferred in lower demand patients above the age of 30. Little consensus was observed among the management of competitive athletes., (Copyright © 2024. Published by Elsevier Inc.)

Patellofemoral instability is influenced by morphological factors and associated with compensational alterations in gait pattern. Recent simulation studies investigated the impact of knee morphology on the stability and loading of the patellofemoral joint but neglected the patient-specific gait pattern. The aim of this study was to investigate the impact of patient-specific gait pattern on muscle forces and joint loading in individuals with patellofemoral instability. Musculoskeletal simulations with a model including a twelve degrees of freedom knee joint were performed based on three-dimensional motion capture data of 21 individuals with chronic patellofemoral instability and 17 healthy control participants. The patellofemoral instability group walked with a less flexed knee joint and reduced knee flexion and abduction moments compared to the control group, which required less quadriceps muscle forces. Lower quadriceps muscle forces resulted in a reduction of tibiofemoral and patellofemoral joint contact forces despite similar walking velocities between both groups. Furthermore, we observed decreased lateralizing patella forces in subjects with patella instability, which could potentially reduce the risk of patella dislocation. Our findings highlight the importance of accounting for the patient-specific gait pattern when analysing knee loads in individuals with patellofemoral instability., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Purpose: Blood flow restriction training (BFRT) has been found to reduce quadriceps atrophy and weakness after anterior cruciate ligament (ACL) surgery. However, the clinical benefit of BFRT as compared to general rehabilitation exercise (GRE) alone remains uncertain. This study aimed to compare the effects of BFRT and GRE on ACL reconstruction rehabilitation through a meta-analysis of randomized controlled trials., Methods: PubMed, Web of Science, EMBASE, Elsevier and Biosis were searched for randomized controlled trials comparing BFRT and GRE following ACL reconstruction. Primary outcomes included muscle strength (extensor and flexor muscle general strength), Lysholm score, the International Knee Documentation Committee (IKDC) score, extensor muscle torque (peak torque and average torque) and muscle cross-sectional area (CSA). The secondary outcomes included a range of motion (ROM), pain, Y-balance and the Patient-Reported Outcomes Measurement Information System (PROMIS)., Results: Thirteen randomized controlled trials involving 376 participants were included. The change in muscle strength (Mean difference, MD: 12.96, 95% confidence interval, [95% CI]: 7.02-18.91, heterogeneity, I 2  = 39%), Lysholm score (MD: 9.41, 95% CI: 8.93-9.88, I 2  = 40%) and IKDC score (MD: 9.88, 95% CI: 0.57-19.19, I 2  = 87%) of the BFRT group were superior to that of the GRE group at the time of last follow-up. However, no significant difference was found between the BFRT and the GRE groups regarding the change in muscle CSA, ROM, extensor muscle torque, pain score, Y-balance and PROMIS., Conclusion: BFRT seems to perform better than GRE in terms of functional improvement and muscle strength following ACL reconstruction, but there seems to be no significant difference between them in terms of joint mobility, pain relief, stability improvement and patient's perception of their disease and treatment., Level of Evidence: Level II., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Purpose: To investigate the return to sport (RTS) rate and the sex-based difference of collegiate athletes after arthroscopic treatment for femoroacetabular impingement (FAI)., Methods: Patients who were collegiate athletes at the time of surgery and underwent hip arthroscopy for treatment of FAI between January 2009 and June 2020 were included. Patients were excluded if they were in their final year of eligibility, graduated, retired, or had plans to retire from collegiate play before surgery. Publicly available data were collected regarding each patient's collegiate team and division and RTS status after surgery. Comparisons were made based on the RTS status and gender., Results: Of the 181 hips (144 athletes) who met the inclusion criteria, 114 were male (63%) and 67 were female (37%), with a median age of 20.4 (range: 18.0-24.5). Eighty-six percent (155 hips) returned to sport at the collegiate level after hip arthroscopy. Males were significantly less likely to return to sport compared with females (82% vs 93%, odds ratio = 2.8, 95% confidence interval: 1.003-7.819, P = .042). Males participated in more contact sports (26% vs 1.5%, P < .001) and had more mixed-type FAI (95.6% vs 80.6%, P = .003) compared with females. In addition, males had more grade 3/4 chondral defects (28% vs 13%, P = .023) and underwent microfracture more frequently (11% vs 3%, P = .047). Further, males had significantly larger postoperative alpha angles (46.2 vs 43.6, P < .001)., Conclusions: Collegiate athletes were found to have a high RTS rate of 86% after arthroscopy for the treatment of FAI; however, males were less likely to RTS compared with females. Sex-based differences were identified in the type of sports, type of FAI, prevalence of severe cartilage damage, and postoperative alpha angle., Level of Evidence: Level IV, retrospective case series., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Background: Reverse total shoulder arthroplasty (rTSA) demonstrates favorable long-term data and has outpaced anatomic total shoulder arthroplasty and hemiarthroplasty as the most-performed shoulder arthroplasty procedure. As indications and outcomes continue to favor rTSA, patients may turn to the internet as an efficient modality to answer various questions or concerns. This study investigates online patient questions pertaining to rTSA and the quality of the websites providing information., Hypotheses: (1) Questions will pertain to surgical indications, timeline of recovery, and postoperative restrictions; (2) the quality and transparency of online information is largely heterogenous., Methods: Three rTSA searches were entered into the Google Web Search. Questions under the "People also ask" tab were expanded sequentially and 100 consecutive results for each query were included for analysis (300 in total). Questions were categorized based on Rothwell's Classification and subcategorized by topic. Websites were categorized by source. Website quality was evaluated by the Journal of the American Medical Association (JAMA) Benchmark Criteria., Results: Most questions fell into the Rothwell Fact category (49.7%). The most common question topics were Timeline of Recovery (17.3%), Specific Activities (14.7%), and Restrictions (11.3%). The least common question topics were Anatomy/Function (0.0%), Cost (0.3%), and Diagnoses/Evaluation (0.3%). The most common websites were Medical Practice (45.0%), Academic (22.3%), and Single Surgeon (12.3%). PubMed articles consisted of 41.2% of Government websites. The average JAMA score for all websites was 1.48 ± 1.27. Government websites had the highest JAMA score (3.11 ± 1.01) and constituted 55.9% of all websites with a score of 4/4. Medical Practice websites had the lowest JAMA score (0.99 ± 0.91)., Conclusion: Patients are interested in the timeline of recovery, ability to perform specific activities after surgery, and short-term and long-term restrictions following rTSA. Although all patients will benefit from education on ways to perform activities of daily living while abiding by postoperative restrictions, physicians should set preoperative expectations regarding return-to-activity following rTSA in younger, more active patients. Finally, surgeons should provide patients with physical booklets and online information available on their websites to avoid reliance on low-quality online sources., (© 2024 The Author(s).)

Purpose: To determine if comparing alpha angle measurements of the outer cortical margin (preoperative alpha angle) and the inner cortical margin (theoretical postoperative alpha angle) on magnetic resonance imaging (MRI) can estimate the amount of sclerotic bone that needs to be resected to restore the alpha angle to normative values (<55⁰) in patients with symptomatic femoroacetabular impingement (FAI)., Methods: A retrospective review was conducted on patients with FAI undergoing primary hip arthroscopy and CAM osteoplasty from June 2013 to February 2017. Inclusion criteria were radiologist-measured alpha angles >70° on 3T oblique axial MRI, unilateral primary hip arthroscopy, and age ≥18. Exclusions included previous hip surgery, hip trauma, avascular necrosis, advanced osteoarthritis, dysplasia, poor quality images, or missing MRI images. Alpha angles were measured preoperatively using the outer cortical margin and postoperatively using the inner cortical margin of femur. Surgeries were performed by the senior surgeon. Paired t-tests compared preoperative and postoperative alpha angles, and intraclass correlation coefficients (ICC) were used to assess inter-rater and intra-rater reliability., Results: One hundred patients (100 hips) were included with an average age of 40.8 years (range, 18.7-64.9), with 75 % being male (n = 75). The average BMI was 24.7 ± 3.9 (range, 17.1-38.8). The average maximum alpha angle at the outer cortical margin was 77.0 ± 4.2° (range, 70.0-90.8), with an ICC for inter-rater reliability of 0.861, indicating excellent agreement. The average inner cortical alpha angle was 46.4 ± 3.4° (range, 36.5-55.4), significantly less than 55° (p<0.001). The mean difference between the outer and inner cortical alpha angles was -30.6 ± 5.1° (p< 0.001)., Conclusions: The difference between outer and inner cortical alpha angles on MRI can accurately estimate the amount of sclerotic bone resection needed to restore the alpha angle to normative values in patients with FAI. This information may be directly applied clinically marker to assess adequacy of CAM resection., (© 2024 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Heart failure is among the first major consequences of heat stress in aquatic ectotherms. Mitochondria produce most of the ATP used by the heart and represent almost half of the volume in cardiac cells. It has therefore been hypothesized that mitochondrial dysfunction may be a major cause of heart failure associated with heat stress. The present study aims to investigate if CTmax is linked to the thermal sensitivity of cardiac mitochondria in the three-spined stickleback (Gasterosteus aculeatus), and if it is influenced by heart fatty acid composition and age. To do so, we measured the CTmax of 30 fish. The cardiac mitochondrial oxygen consumption was measured by high resolution respirometry at three temperatures and heart lipid profiles were obtained by gas chromatography (GC) coupled with a flame ionization detector (FID). Fish age was estimated via otolith readings. Fatty acid profiles showed no correlation with CTmax, but EPA levels were higher in older individuals. Mitochondrial respiration was measured in 35 fish using high-resolution respirometry. It was strongly affected by temperature and showed a drastic drop in OXPHOS respiration fed by complex I and complex I+complex II, while uncoupled respiration plateaued at CTmax temperature. Our results suggest that complex I is an important modulator of the impact of temperature on mitochondrial respiration at high temperatures but is not the main limiting factor in physiological conditions (maximal OXPHOS). Mitochondrial respiration was also affected by fish age, showing a general decrease in older individuals., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Background: Labral repair has become the preferred method for the arthroscopic treatment of acetabular labral tears that are associated with femoroacetabular impingement (FAI) resulting in pain and dysfunction. Labral reconstruction is performed mainly in revision hip arthroscopy but can be utilized in the primary setting for absent or calcified labra. The purpose of this study was to compare the minimum 2-year patient-reported outcomes (PROs) and risk of revision or conversion to arthroplasty between primary labral reconstruction and primary labral repair., Methods: Patients with FAI who underwent primary hip arthroscopy with labral repair or reconstruction performed by the senior author between 2006 and 2018 were identified from a prospectively enrolled patient outcome registry. Exclusion criteria included confounding injuries, dysplasia, prior ipsilateral hip surgery, or a joint space of <2 mm. Patients who were 18 to 80 years old were eligible for inclusion. Multiple regression with inverse propensity score weighting was conducted to estimate the average treatment effect in the treated (ATT) for labral reconstruction versus labral repair with respect to postoperative PROs and the likelihood of subsequent surgery (revision hip arthroscopy or conversion to arthroplasty). PRO end points included the Hip Outcome Score Activities of Daily Living subscale (HOS-ADL), modified Harris hip score, Western Ontario and McMaster Universities Osteoarthritis Index total score (WOMAC), 12-Item Short Form Health Survey Physical Component Summary score (SF-12 PCS), and patient satisfaction., Results: A total of 150 hips undergoing primary labral reconstruction and 998 hips undergoing primary labral repair were included. The median follow-up time was 5.3 years in the reconstruction group and 5.8 years in the repair group. Compared with labral repair, labral reconstruction was associated with a higher risk of conversion to total hip arthroplasty (THA) (20% versus 7%; adjusted odds ratio, 3.2; 95% confidence interval [CI], 1.2 to 8.8; p = 0.024). Inverse propensity score-weighted multiple regression estimated a significant negative effect of labral reconstruction, relative to labral repair, on the postoperative values for the HOS-ADL (ATT, -3.3; 95% CI, -5.8 to -0.7; p = 0.012) and WOMAC (ATT, 2.6; 95% CI, 0.1 to 5.2; p = 0.044)., Conclusions: Compared with primary labral reconstruction, primary labral repair resulted in better postoperative HOS-ADL and WOMAC values and decreased conversion to THA. These findings were demonstrated in both the unadjusted group comparisons and multivariable modeling. These data support the use of labral repair in the primary setting of labral tears and the reservation of labral reconstruction for more advanced labral pathology or for revision cases., Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: No external funding was received for this work. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/I166 )., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: There is no clear consensus regarding patient populations at highest risk for complications from simultaneous bilateral total knee arthroplasty (TKA). The purpose of this study was to determine whether the comorbidities comprising the modified Frailty Index (mFI) were correlated with poor outcomes following simultaneous bilateral TKA., Methods: From 2006 to 2019, patients undergoing bilateral TKA aged 50 years or older were identified in a national database. The 5-item mFI was calculated based on the presence of five comorbidities: diabetes, congestive heart failure, hypertension, chronic obstructive pulmonary disease, and dependent functional status. Chi-squared and multivariable regression analyses were used to evaluate the association of mFI scores with postoperative complications., Results: The study analyzed 8,776 patients with an average age of 65 years. After adjustment on multivariable regression analysis, compared to patients with a mFI score of 0, those with a score of 1 had an increased risk of pulmonary complication (OR 3.14; p = 0.011), renal problem (OR 12.86; p = 0.022), sepsis complication (OR 2.82; p = 0.024), postoperative transfusion (OR 1.19; p = 0.012), and non-home discharge (OR 1.17; p = 0.002).Patients with a score of 2 compared to 0 had similar complications when compared. These patients had an increased risk of cardiac complication (OR 4.84; p = 0.009) and prolonged hospital stay (OR 4.06; p < 0.001)., Conclusion: Increased mFI scores were associated with significantly higher complication rates in patients undergoing simultaneous bilateral TKA compared to unilateral TKA. Our results can be used to identify which patients may need a staged bilateral TKA or preoperative optimization to safely undergo a simultaneous bilateral TKA., Level of Evidence: III., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Anterior instability of the sternoclavicular joint (SCJ) is a rare but potentially devastating pathological condition, particularly when it occurs in young or active patients. SCJ reconstruction using hamstring tendon autograft is a commonly used treatment option, yet to date results are limited to small case series. Studies on baseline, preoperative factors and their association with postoperative outcome are limited., Purpose: To assess the midterm clinical outcomes and survivorship after SCJ reconstruction using hamstring tendon autograft in patients experiencing anterior SCJ instability and to determine whether baseline patient or causative factors are associated with postoperative outcomes or patient satisfaction., Study Design: Case series; Level of evidence, 4., Methods: Patients who underwent SCJ reconstruction with a hamstring tendon autograft for anterior SCJ instability between October 2005 and October 2020 were included in this retrospective single-center study. At a minimum of 2 years postoperatively, clinical outcomes were collected, including the following patient-reported outcomes (PROs): the 12-Item Short Form Survey (SF-12) score; American Shoulder and Elbow Surgeons (ASES) score; Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score; Single Assessment Numeric Evaluation (SANE) score; and visual analog scale (VAS) pain score. Subjective postoperative satisfaction with the procedure was quantified on a scale from 0 (very unsatisfied) to 10 (very satisfied). The predictive role of patient factors, including age, sex, and injury in dominant arm, on postoperative PROs and satisfaction at short-term follow-up was evaluated using multiple linear regression., Results: A total of 49 patients (mean age, 29.6 ± 16.2 years; range 13.8-67.1 years; 27 females) were included in the final analysis. At a mean follow-up of 3.9 ± 2.1 years, all PROs had significantly improved, including the mean SF-12 Physical Component Summary score (40.4 ± 6.8 to 52.6 ± 6.9; P < .001), ASES score (54.9 ± 20.4 to 91.0 ± 11.3; P < .001), QuickDASH score (41.2 ± 18.5 to 10.2 ± 9.1; P < .001); SANE score (50.2 ± 21.1 to 88.3 ± 8.8; P < .001), VAS pain score (4.4 ± 2.6 to 0.8 ± 1.4; P < .001), and VAS pain score at its worst (7.4 ± 2.5 to 3.3 ± 2.6; P < .001). The median postoperative satisfaction score was 9 (range, 1-10). Revision-free survivorship was 95.9%. Male patients had a significantly lower VAS pain score at its worst compared with female patients (2.6 ± 2.6 vs 4.1 ± 2.4; P = .045); higher age was significantly correlated with a worse QuickDASH score (correlation coefficient, 0.314; P = .036). Overhead athletes had a significantly lower propensity to return to sport compared with nonoverhead athletes ( P = .043), with only 45% of the overhead athletes returning to a level similar to their preinjury level, whereas 81% of the nonoverhead athletes were able to do so., Conclusion: The significant improvements in clinical and sport-specific outcomes and high patient satisfaction after SCJ reconstruction with a hamstring tendon autograft demonstrate the success of this procedure in treating anterior SCJ instability. Male sex and younger patient age are associated with superior outcomes, while overhead athletes have to be counseled about difficulties of returning to preinjury level of sport postoperatively., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: M.C.R., A.R.G., J.C.R., and M.P.H. are supported by the Steadman Philippon Research Institute (SPRI), which is a 501(c)(3) nonprofit institution supported financially by private donations and corporate support. SPRI exercises special care to identify any financial interests or relationships related to research conducted here. During the past calendar year, SPRI has received grant funding or in-kind donations from Arthrex, Canon, DJO, Icarus Medical, Medtronic, Ossur, Smith & Nephew, SubioMed, Stryker, and Wright Medical. P.C. has received support for education from Smith & Nephew and Encore Medical; and a grant from DJO. M.T.P. has received royalties from Arthrex, Arthrosurface, Responsive Arthroscopy, and Anika Therapeutics; consulting fees from Arthrex, Joint Restoration Foundation (JRF), Zimmer Biomet Holdings, and Arthrosurface; grants from the Department of Defense (DoD), the National Institute of Health (NIH), and DJO; and honoraria from Flexion Therapeutics. P.J.M. has received royalties, consulting fees, and research support from Arthrex; and holds stock in VuMedi. 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/objectives: Long-standing groin pain is a severe issue for athletes, often associated with the cleft sign on magnetic resonance imaging (MRI) scans, yet its underlying causes are poorly understood. The purpose of this study is to histologically examine the pubic plate structure in cadavers with and without the cleft sign on MRI, shedding light on the pathology behind the cleft sign., Methods: Three fresh human pelvic cadavers underwent 3.0T MRI to detect the cleft sign before histological dissection of pubic plates. Pubic plate tissues were fixed in formalin, decalcified, and processed. Of the two cleft sign-negative specimens, one was cut into sagittal sections, and the other was cut into coronal sections for histology. For the cleft sign positive specimen, a sagittal section was cut. Moreover, 5 µm thick sections were cut at different axial levels for each orientation. Sections were subjected to Safranin O, Alcian blue, and Herovici's staining or hematoxylin and eosin staining., Results: MRI confirmed that one specimen had a cleft sign in the inferior region on both sides of the pubis and that two specimens had no cleft sign. Both sagittal and coronal sections showed the presence of a cartilage structure continuing from the pubic symphysis to 3 mm laterally within the pubic plate. In the specimen with a positive cleft sign, cartilage damage within the pubic symphysis and pubic plate was identified as revealed by Safranin O staining, Herovici's staining, and H&E staining., Conclusions: This study elucidated the existence of a cartilage component extending from the pubic symphysis to the pubic plate. The cleft sign in MRI correlated with a disruption in the cartilage component in histology within this specific area.

Treating cartilage damage is challenging as its ability for self-regeneration is limited. Left untreated, it can progress to osteoarthritis (OA), a joint disorder characterized by the deterioration of articular cartilage and other joint tissues. Surgical options, such as microfracture and cell/tissue transplantation, have shown promise as techniques to harness the body's endogenous regenerative capabilities to promote cartilage repair. Nonetheless, these techniques have been scrutinized due to reported inconsistencies in long-term outcomes and the tendency for the defects to regenerate as fibrocartilage instead of the smooth hyaline cartilage native to joint surfaces. Orthobiologics are medical therapies that utilize biologically derived substances to augment musculoskeletal healing. These treatments are rising in popularity because of their potential to enhance surgical standards of care. More recent developments in orthobiologics have focused on the role of exosomes in articular cartilage repair. Exosomes are nano-sized extracellular vesicles containing cargo such as proteins, lipids, and nucleic acids, and are known to facilitate intercellular communication, though their regenerative potential still needs to be fully understood. This review aims to demonstrate the advancements in cartilage regeneration, highlight surgical and biological treatment options, and discuss the recent strides in understanding the precise mechanisms of action involved.

Osteoarthritis (OA) pain is often associated with the expression of tumor necrosis factor alpha (TNF-α), suggesting that TNF-α is one of the main contributing factors that cause inflammation, pain, and OA pathology. Thus, inhibition of TNF-α could potentially improve OA symptoms and slow disease progression. Anti-TNF-α treatments with antibodies, however, require multiple treatments and cannot entirely block TNF-α. TNF-α-induced protein 8-like 2 (TIPE2) was found to regulate the immune system's homeostasis and inflammation through different mechanisms from anti-TNF-α therapies. With a single treatment of adeno-associated virus (AAV)-TIPE2 gene delivery in the accelerated aging Zmpste24 -/- (Z24 -/- ) mouse model, we found differences in Safranin O staining intensity within the articular cartilage (AC) region of the knee between TIPE2-treated mice and control mice. The glycosaminoglycan content (orange-red) was degraded in the Z24 -/- cartilage while shown to be restored in the TIPE2-treated Z24 -/- cartilage. We also observed that chondrocytes in Z24 -/- mice exhibited a variety of senescent-associated phenotypes. Treatment with TIPE2 decreased TNF-α-positive cells, β-galactosidase (β-gal) activity, and p16 expression seen in Z24 -/- mice. Our study demonstrated that AAV-TIPE2 gene delivery effectively blocked TNF-α-induced inflammation and senescence, resulting in the prevention or delay of knee OA in our accelerated aging Z24 -/- mouse model., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.)

Background: Individual maximum joint and segment angular velocities have shown positive associations with throwing arm kinetics and ball velocity in baseball pitchers., Purpose: To observe how cumulative maximum joint and segment angular velocities, irrespective of sequence, affect ball velocity and throwing arm kinetics in high school pitchers., Study Design: Descriptive laboratory study., Methods: High school (n = 55) pitchers threw 8 to 12 fastball pitches while being evaluated with 3-dimensional motion capture (480 Hz). Maximum joint and segment angular velocities (lead knee extension, pelvis rotation, trunk rotation, shoulder internal rotation, and forearm pronation) were calculated for each pitcher. Pitchers were classified as overall fast, overall slow, or high velocity for each joint or segment velocity subcategory, or as population, with any pitcher eligible to be included in multiple subcategories. Kinematic and kinetic parameters were compared among the various subgroups using t tests with post hoc regressions and multivariable regression models created to predict throwing arm kinetics and ball velocity, respectively., Results: The lead knee extension and pelvis rotation velocity subgroups achieved significantly higher normalized elbow varus torque ( P = .016) and elbow flexion torque ( P = .018) compared with population, with equivalent ball velocity ( P = .118). For every 1-SD increase in maximum pelvis rotation velocity (87 deg/s), the normalized elbow distractive force increased by 4.7% body weight (BW) ( B = 0.054; β = 0.290; P = .013). The overall fast group was older (mean ± standard deviation, 16.9 ± 1.4 vs 15.4 ± 0.9 years; P = .007), had 8.9-mph faster ball velocity (32.7 ± 3.1 vs 28.7 ± 2.3 m/s; P = .002), and had significantly higher shoulder internal rotation torque (63.1 ± 17.4 vs 43.6 ± 12.0 Nm; P = .005), elbow varus torque (61.8 ± 16.4 vs 41.6 ± 11.4 Nm; P = .002), and elbow flexion torque (46.4 ± 12.0 vs 29.5 ± 6.8 Nm; P < .001) compared with the overall slow group. A multiregression model for ball velocity based on maximum joint and segment angular velocities and anthropometrics predicted 53.0% of variance., Conclusion: High school pitchers with higher maximum joint and segment velocities, irrespective of sequence, demonstrated older age and faster ball velocity at the cost of increased throwing shoulder and elbow kinetics., Clinical Relevance: Pitchers and coaching staff should consider this trade-off between faster ball velocity and increasing throwing arm kinetics, an established risk factor for elbow injury., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: B.D. is a previous paid employee of Motus Global. J.J.R. has received hospitality payments from Smith + Nephew and grants from Arthrex. B.J.E. has received support for education from Arthrex, Smith + Nephew, Pinnacle, and Gotham Surgical; and consulting fees from DePuy Synthes. M.C.C. has received support for education from Paladin Technology Solutions and Liberty Surgical. M.G.C. has received grants from Arthrex and DJO. J.S.D. has received consulting fees from Arthrex, Linvatec Corp, Trice Medical, Merck Sharp & Dohme, and Wright Medical; royalties from Zimmer Biomet and Linvatec Corp; research support from Arthrex; and a gift from Trice Medical; he was previously an unpaid consultant for Motus 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.

Background: Intraarticular hip pain represents a substantial clinical challenge, with recent studies implicating lesions in the ligamentum teres as potential contributors. Even more so, damage to the ligamentum teres is particularly prevalent among young patients undergoing joint-preserving interventions. Although several studies have investigated the biomechanical attributes of the ligamentum teres, inconsistencies in reported findings and reliance on cadaveric or animal models have raised concerns regarding the extrapolation of results to clinical practice. Furthermore, there is a lack of research examining ligamentum teres biomechanics specifically within the relevant patient cohort-individuals who benefit from joint-preserving surgical interventions., Questions/purposes: We sought (1) to determine the biomechanical properties (ultimate load to failure, tensile strength, stiffness, and elastic modulus) of fresh-frozen ligaments from patients undergoing surgical hip dislocation, and (2) to identify patient-specific factors that are associated with them., Methods: This was an institutional review board-approved study on intraoperatively harvested ligamentum teres from 74 consecutive patients undergoing surgical hip dislocation for joint preservation (August 2021 to September 2022). After the exclusion of patients with previous surgery, posttraumatic deformities, avascular necrosis, slipped capital femoral epiphysis, and Perthes disease, 31 ligaments from 31 patients were analyzed. The mean age of the study group was 27 ± 8 years, and 61% (19) of participants were male. The main indication for surgery was femoroacetabular impingement. Standardized AP pelvic and axial radiographs and CT scans were performed in all patients for better radiological description of the population and to identify associated radiological factors. The ligament was thoroughly transected at its origin on the fossa acetabuli and at the insertion area on the fovea capitis and stored at -20°C until utilization. Specimens were mounted to a materials testing machine via custom clamps that minimized slippage and the likelihood of failure at the clamp. Force-displacement and stress-strain curves were generated. Ultimate failure load (N), tensile strength (MPa), stiffness (N/mm), and elastic modulus (MPa) were determined. Using a multivariate regression analysis and a subgroup analysis, we tested demographic, degenerative, and radiographic factors as potential associated factors., Results: The ligamentum teres demonstrated an ultimate load to failure of 126 ± 92 N, and the tensile strength was 1 ± 1 MPa. The ligaments exhibited a stiffness of 24 ± 15 N/mm and an elastic modulus of 7 ± 5 MPa. After controlling for potential confounding variables like age, fossa/fovea degeneration, and acetabular/femoral morphologies, we found that female sex was an independent factor for higher tensile strength, stiffness, and elastic modulus. Excessive femoral version was independently associated with lower load to failure (HR 122 [95% CI 47 to 197]) and stiffness (HR 15 [95% CI 2 to 27]). Damage to the acetabular fossa was associated with reduced load to failure (HR -93 [95% CI -159 to -27])., Conclusion: Overall, the ligamentum teres is a relatively weak ligament. Sex, degeneration, and excessive femoral version are influencing factors on strength of the ligamentum teres. The ligamentum teres exhibits lower strength compared with other joint-stabilizing ligaments, which calls into question its overall contribution to hip stability., Clinical Relevance: Young patients undergoing hip-preserving surgery are the population at risk for ligamentum teres lesions. Baseline values for load to failure, tensile strength, elastic modulus, and stiffness are needed to better understand those lesions in this cohort of interest., Competing Interests: Each author certifies that there are no funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article related to the author or any immediate family members. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2024 by the Association of Bone and Joint Surgeons.)

Background: While microfracture has been shown to be an effective treatment for chondral lesions in the knee, evidence to support its use for chondral defects in the shoulder is limited to short-term outcomes studies. The purpose of this study is to determine if microfracture provides pain relief and improved shoulder function in patients with isolated focal chondral defects of the humeral head at a minimum 5-year follow-up., Methods: Patients who underwent microfracture procedure for isolated focal chondral defects of the humeral head with a minimum follow-up of 5 years between 02/2006 and 08/2016 were included. At minimum 5-year follow-up, pre- and postoperative patient-reported outcome (PRO) measures were collected, including the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), Short Form-12 (SF-12) Physical Component Summary (PCS), Visual Analog Scale (VAS) for pain, and patient satisfaction level (1 = unsatisfied, 10 = very satisfied). Demographic, injury, and surgical data were retrospectively reviewed. Surgical failure was defined as revision surgery for humeral chondral defects or conversion to arthroplasty. Kaplan-Meier analysis was performed to determine survivorship at 5 years., Results: A total of 17 patients met inclusion/exclusion criteria. There were 15 men and 2 women with an average age of 51 years (range 36-69) and an average follow-up of 9.4 years (range 5.0-15.8). The median ASES score improved from 62 (range: 22-88) preoperatively to 90 (range: 50-100) postoperatively (P = .011). Median satisfaction was 8 out of 10 (range: 2-10). There was no correlation between patient age or defect size and PROs. Postoperatively, patients reported significant improvements in recreational and sporting activity as well as the ability to sleep on the affected shoulder (P ≤ .05). Three patients failed and required revision surgery. The Kaplan-Meier analysis determined an overall survivorship rate of 80% at 5 years., Conclusion: The presented study illustrates significant improvements for PROs, improved ability to perform recreational and sporting activities, and a survival rate of 80% at a mean of 9.4 years after microfracture for focal chondral humeral head defects., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Subscapularis tendon (SSc) dysfunction after total shoulder arthroplasty (TSA) results in poor functional outcomes. There have been numerous SSc repair constructs tested biomechanically and clinically; however, none has been demonstrated as superior. Newer techniques and implants have emerged but have not been fully tested., Hypothesis: We hypothesized that the unicortical button (UB) fixation would provide significantly improved restoration of the anatomic footprint and biomechanical properties compared with transosseous (TO) repair of the SSc., Methods: A digital footprint of SSc humeral insertion was obtained in 6 pairs of fresh-frozen cadaveric shoulders using a 3-dimensional digitizer. A complete SSc tear was created, and each pair of shoulders was randomized to either SSc repair with UB or TO repair. Each specimen underwent a cyclic loading protocol, followed by pull to failure. The failure load, elongation at failure, gapping failure, number of cycles until failure, the load at key gapping points (1 mm, 3 mm, 5 mm, and 10 mm), and the failure mode were recorded using high-resolution video recording. Three-dimensional surfaces of the insertion footprint and repair site were obtained, and surface areas were calculated using a custom MATLAB script and laser scanner. Paired t tests were conducted to compare differences between the 2 repair groups., Results: Failure load was significantly higher in the UB group (382.4 N ± 56.5 N) than in the TO group (253.6 N ± 103.4 N, P = .005). TO repair provided higher gapping at failure (28.8 mm ± 8.2 mm) than UB repair (10.4 mm ± 6.8 mm, P = .0017). UB repair had significantly higher load at the 1-mm, 5-mm, and 10-mm gapping than TO repair, with P = .042, P = .033, and P = .0076, respectively. There were no significant differences in elongation failure, the difference in footprint area from native to repair states, or the percentage of the restored footprint area between the groups (P = .26, P = .18, and P = .21, respectively)., Conclusions: The UB fixation showed a significantly lower gap at failure, higher failure load and number of cycles until failure, and higher gap loads than the traditional TO repair for SSc. Although more clinical research is necessary, the UB fixation that uses cortical bone presents promising results., (Copyright © 2024. Published by Elsevier Inc.)

Regeneration of hyaline cartilage in human-sized joints remains a clinical challenge, and it is a critical unmet need that would contribute to longer healthspans. Injectable scaffolds for cartilage repair that integrate both bioactivity and sufficiently robust physical properties to withstand joint stresses offer a promising strategy. We report here on a hybrid biomaterial that combines a bioactive peptide amphiphile supramolecular polymer that specifically binds the chondrogenic cytokine transforming growth factor β-1 (TGFβ-1) and crosslinked hyaluronic acid microgels that drive formation of filament bundles, a hierarchical motif common in natural musculoskeletal tissues. The scaffold is an injectable slurry that generates a porous rubbery material when exposed to calcium ions once placed in cartilage defects. The hybrid material was found to support in vitro chondrogenic differentiation of encapsulated stem cells in response to sustained delivery of TGFβ-1. Using a sheep model, we implanted the scaffold in shallow osteochondral defects and found it can remain localized in mechanically active joints. Evaluation of resected joints showed significantly improved repair of hyaline cartilage in osteochondral defects injected with the scaffold relative to defects injected with the growth factor alone, including implantation in the load-bearing femoral condyle. These results demonstrate the potential of the hybrid biomimetic scaffold as a niche to favor cartilage repair in mechanically active joints using a clinically relevant large-animal model., Competing Interests: Competing interests statement:J.A.L., N.A.S., M.T.M., and S.I.S. are inventors on patent application WO2023056433A1 filed by Northwestern University. N.A.S. and S.I.S. are stockholders of Amphix Bio, Inc.

Background: Kinematic parameters predictive of pitch velocity have been evaluated in adolescent and collegiate baseball pitchers; however, they have not been established for high school or professional pitchers., Purpose: To create multiregression models using anthropometric and kinematics features most predictive for pitch velocity in high school and professional pitchers and compare them with prior multiregression models evaluating other playing levels., Study Design: Descriptive laboratory study., Methods: High school (n = 59) and professional (n = 337) baseball pitchers threw 8 to 12 fastballs while being evaluated with 3-dimensional motion capture (480 Hz). Using anthropometric and kinematic variables, multiregression models for pitch velocity were created for each group. A systematic review was conducted to determine previous studies that established kinematic models for ball velocity in youth, high school, and collegiate pitchers., Results: Leg length was predictive of pitch velocity for high school and professional pitchers ( P < .001 for both). When compared with previously established models for pitch velocity, almost all groups were distinct from one another when assessing age ( P maximum < .001), weight ( P max = .0095), and pitch velocity ( P max < .001). Stride length was a significant predictor for the youth/high school pitchers, as well as the current study's high school and professional pitchers ( P < .001 for all). Maximal shoulder external rotation (collegiate: P = .001; professional: P < .001) and maximal elbow extension velocity (high school/collegiate: P = .024; collegiate: P < .001; professional: P = .006) were shared predictors for the collegiate and current study's professional group multiregression models. Trunk flexion at ball release was a commonly shared predictor in the youth/high school ( P = .04), high school/collegiate ( P = .003), collegiate ( P < .001), and the current study's professional group ( P < .001)., Conclusion: Youth, high school, collegiate, and professional pitchers had unique, predictive kinematic and anthropometric features predictive of pitch velocity. Leg length, stride length, trunk flexion at ball release, and maximal shoulder external rotation were predictive features that were shared between playing levels., Clinical Relevance: Coaches, clinicians, scouts, and pitchers can consider both the unique and the shared predictive features at each playing level when attempting to maximize pitch velocity., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A.N. has received grant support from Arthrex, education payments from Arthrex and SeaPearl, and hospitality payments from Zimmer Biomet and Stryker. M.C.C. has received grant support from Arthrex and DJO. J.J.R. has received grant support from Arthrex and hospitality payments from Smith+Nephew. J.S.D. has received education payments from Gotham Surgical; consulting fees from Arthrex, KCI, and Trice Medical; nonconsulting fees from Arthrex; and royalties from Arthrex and Linvatec. 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., (© The Author(s) 2024.)

Objectives: The purpose of this study was to determine the correlation between microscopic degeneration in the long head of the biceps tendon (LHBT) and the apoptotic process. Methods: This study included 26 consecutive patients who had undergone arthroscopic biceps tenodesis or tenotomy for symptomatic LHBT with or without concomitant rotator cuff tears (RCTs). Histological examination of the specimens under a light microscope was conducted after staining with hematoxylin, eosin, and the Alcian blue. Histopathological changes were assessed using the original Bonar score and the modified Bonar score and then correlated with the expression of the subsequent apoptosis markers: activated caspase-3 (casp3), tumor protein p53 (p53), and B-cell lymphoma 2 (BCL-2). Results: The mean original Bonar score was 8.65 (range 5-11), while the modified Bonar score was 7.61. There was no correlation between the original Bonar score and the age of the patients, but a positive correlation was found between the modified Bonar score and the age of the patients ( p = 0.0022). There was no correlation between the age of patients and the expression indexes of BCL-2 and casp3. However, the expression of the p53 index showed a positive correlation with patient aging ( p = 0.0441). Furthermore, there was no correlation observed between the expression of apoptotic indexes and both the original and modified Bonar scale. Conclusions: In LHB tendinopathy, the expression of apoptosis does not seem to directly correlate with the extent of degeneration, particularly in the late stages of tendinopathy. However, the transformations observed in collagen and ground substance were significantly associated with age, as well as tendinous tissue degeneration quantified according to modified Bonar score. The age of patients was also linked with the expression of the p53 index, as an increased apoptosis in the studied population.

Proteomics is a growing field that offers insights into various aspects of disease processes and therapy responses. Within the field of orthopedics, there are a variety of diseases that have a poor prognosis due to a lack of targeted curative therapy or disease modifying therapy. Other diseases have been difficult to manage in part due to lack of clinical biomarkers that offer meaningful insight into disease progression or severity. As an emerging technology, proteomics has been increasingly applied in studying bone biology and an assortment of orthopedics related diseases, such as osteoarthritis, osteosarcoma and bone tumors, osteoporosis, traumatic bone injury, spinal cord injury, hip and knee arthroplasty, and fragile healing. These efforts range from mechanistic studies for elucidating novel insights in tissue activity and metabolism to identification of candidate biomarkers for diagnosis, prognosis, and targeted treatment. The knowledge gained from these proteomic and functional studies has provided unique perspectives in studying orthopedic diseases. In this review, we seek to report on the current state of the proteomic study in the field of orthopedics, overview the advances in clinically applicable discoveries, and discuss the opportunities that may guide us for future research., (© 2024 Orthopaedic Research Society.)

Background: The aim of this study was to define the minimal clinically important difference (MCID) values for patient-reported outcomes (PROs) after arthroscopic treatment of snapping scapula syndrome (SSS) using a distribution-based method, and to identify demographic, clinical, and intraoperative factors significantly associated with the achievement of MCID. It was hypothesized that subjective satisfaction scores after the procedure would be strongly associated with the achievement of MCID thresholds for the PROs and that pain, preoperative response to injection, and a scapulectomy in addition to bursal resection would be predictive of clinically relevant improvement., Methods: Patients who underwent arthroscopic treatment of SSS between October 2005 and September 2020 with a minimum of 2-year short-term postoperative follow-up were enrolled in this retrospective single-center study. The MCID was calculated using a distribution-based approach for the following PROs: 12-Item Short Form Health Survey (SF-12), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) pain "today" and "at worst." The association between achievement of the MCID and postoperative subjective satisfaction was investigated, and factors associated with achievement of MCID were determined using bivariate analysis., Results: Of a total of 190 patients assessed for eligibility, 77 patients (38.1 ± 14.3 years; 36 females) were included. Within the study population, statistically significant improvements in postoperative SF-12 physical component summary (PCS) (P < .001) and mental component summary (MCS) (P < 0.034), ASES (P < .001), QuickDASH (P < .001), SANE (P < .001), and VAS pain (P < .001) scores were observed at the minimum 2-year follow-up. The calculated MCID threshold values based on the study population were 5.0 for SF-12 PCS, 5.8 for SF-12 MCS, 11.3 for ASES, -10.5 for QuickDASH, 14.7 for SANE, 1.5 for VAS pain, and 1.7 for VAS pain at worst. Reaching the MCID was strongly associated with postoperative satisfaction (rated on a scale of 1-10). Across the PROs, younger age, favorable preoperative response to injection, partial scapuloplasty or scapulectomy, no prior surgery, and pain and function at baseline were significantly associated with attaining MCID., Conclusions: Patients who underwent arthroscopic treatment for SSS experienced clinically significant improvements in functional scores, pain, and quality of life. This study demonstrated predictive roles for certain patient-specific factors and diagnostic variables for achieving MCID in PROs, which may help surgeons preoperatively assess the probability of success and manage patient expectations., (Copyright © 2024 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Study Design: Retrospective multi-site cohort study., Objectives: To develop an accurate machine learning predictive model using predictor variables from the acute rehabilitation period to determine ambulatory status in spinal cord injury (SCI) one year post injury., Setting: Model SCI System (SCIMS) database between January 2000 and May 2019., Methods: Retrospective cohort study using data that were previously collected as part of the SCI Model System (SCIMS) database. A total of 4523 patients were analyzed comparing traditional models (van Middendorp and Hicks) compared to machine learning algorithms including Elastic Net Penalized Logistic Regression (ENPLR), Gradient Boosted Machine (GBM), and Artificial Neural Networks (ANN)., Results: Compared with GBM and ANN, ENPLR was determined to be the preferred model based on predictive accuracy metrics, calibration, and variable selection. The primary metric to judge discrimination was the area under the receiver operating characteristic curve (AUC). When compared to the van Middendorp all patients (0.916), ASIA A and D (0.951) and ASIA B and C (0.775) and Hicks all patients (0.89), ASIA A and D (0.934) and ASIA B and C (0.775), ENPLR demonstrated improved AUC for all patients (0.931), ASIA A and D (0.965) ASIA B and C (0.803)., Conclusions: Utilizing artificial intelligence and machine learning methods are feasible for accurately classifying outcomes in SCI and may provide improved sensitivity in identifying which individuals are less likely to ambulate and may benefit from augmentative strategies, such as neuromodulation. Future directions should include the use of additional variables to further refine these models., (© 2024. The Author(s), under exclusive licence to International Spinal Cord Society.)

The commitment of stem cells to differentiate into osteoblasts is a highly regulated and complex process that involves the coordination of extrinsic signals and intrinsic transcriptional machinery. While rodent osteoblastic differentiation has been extensively studied, research on human osteogenesis has been limited by cell sources and existing models. Here, we systematically dissect human pluripotent stem cell-derived osteoblasts to identify functional membrane proteins and their downstream transcriptional networks involved in human osteogenesis. Our results reveal an enrichment of type II transmembrane serine protease CORIN in humans but not rodent osteoblasts. Functional analyses demonstrated that CORIN depletion significantly impairs osteogenesis. Genome-wide chromatin immunoprecipitation enrichment and mechanistic studies show that p38 MAPK-mediated CCAAT enhancer binding protein delta (CEBPD) upregulation is required for CORIN-modulated osteogenesis. Contrastingly, the type I transmembrane heparan sulfate proteoglycan SDC1 enriched in mesenchymal stem cells exerts a negative regulatory effect on osteogenesis through a similar mechanism. Chromatin immunoprecipitation-seq, bulk and single-cell transcriptomes, and functional validations indicated that CEBPD plays a critical role in controlling osteogenesis. In summary, our findings uncover previously unrecognized CORIN-mediated CEBPD transcriptomic networks in driving human osteoblast lineage commitment., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Published by Elsevier Inc.)

The mechanism regulating cellular senescence of postmitotic muscle cells is still unknown. cGAS-STING innate immune signaling was found to mediate cellular senescence in various types of cells, including postmitotic neuron cells, which however has not been explored in postmitotic muscle cells. Here by studying the myofibers from Zmpste24 -/- progeria aged mice [an established mice model for Hutchinson-Gilford progeria syndrome (HGPS)], we observed senescence-associated phenotypes in Zmpste24 -/- myofibers, which is coupled with increased oxidative damage to mitochondrial DNA (mtDNA) and secretion of senescence-associated secretory phenotype (SASP) factors. Also, Zmpste24 -/- myofibers feature increased release of mtDNA from damaged mitochondria, mitophagy dysfunction, and activation of cGAS-STING. Meanwhile, increased mtDNA release in Zmpste24 -/- myofibers appeared to be related with increased VDAC1 oligomerization. Further, the inhibition of VDAC1 oligomerization in Zmpste24 -/- myofibers with VBIT4 reduced mtDNA release, cGAS-STING activation, and the expression of SASP factors. Our results reveal a novel mechanism of innate immune activation-associated cellular senescence in postmitotic muscle cells in aged muscle, which may help identify novel sets of diagnostic markers and therapeutic targets for progeria aging and aging-associated muscle diseases., (© 2024. The Author(s).)

Chronic Osgood-Schlatter disease can cause significant knee pain and can result in severe functional deficits. For large, painful Osgood-Schlatter disease ossicles refractory to conservative management, surgical ossicle excision can provide resolution of symptoms. After diagnostic arthroscopy and intra-articular debridement, our preferred excision technique uses an open incision for direct visualization and removal of intratendinous ossicles, followed by distal patellar tendon repair and subsequent fixation with FiberTape sutures and knotless anchors to the tibial tubercle., (© 2024 The Authors.)

Purpose: The purpose of this study was to evaluate the perspective of orthopaedic surgeons on the impact of artificial intelligence (AI) and to evaluate the influence of experience, workplace setting and familiarity with digital solutions on views on AI., Methods: Orthopaedic surgeons of the AGA Society for Arthroscopy and Joint Surgery were invited to participate in an online, cross-sectional survey designed to gather information on professional background, subjective AI knowledge, opinion on the future impact of AI, openness towards different applications of AI, and perceived advantages and disadvantages of AI. Subgroup analyses were performed to examine the influence of experience, workplace setting and openness towards digital solutions on perspectives towards AI., Results: Overall, 360 orthopaedic surgeons participated. The majority indicated average (43.6%) or rudimentary (38.1%) AI knowledge. Most (54.5%) expected AI to substantially influence orthopaedics within 5-10 years, predominantly as a complementary tool (91.1%). Preoperative planning (83.8%) was identified as the most likely clinical use case. A lack of consensus was observed regarding acceptable error levels. Time savings in preoperative planning (62.5%) and improved documentation (81%) were identified as notable advantages while declining skills of the next generation (64.5%) were rated as the most substantial drawback. There were significant differences in subjective AI knowledge depending on participants' experience ( p  = 0.021) and familiarity with digital solutions ( p  < 0.001), acceptable error levels depending on workplace setting ( p  = 0.004), and prediction of AI impact depending on familiarity with digital solutions ( p  < 0.001)., Conclusion: The majority of orthopaedic surgeons in this survey anticipated a notable positive impact of AI on their field, primarily as an assistive technology. A lack of consensus on acceptable error levels of AI and concerns about declining skills among future surgeons were observed., Level of Evidence: Level IV, cross-sectional study., Competing Interests: Peter Angele is a consultant for Aesculap/TETEC and Arthrex. The remaining authors declare no conflict of interest., (© 2024 The Author(s). Journal of Experimental Orthopaedics published by John Wiley & Sons Ltd on behalf of European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Purpose: To systematically review existing literature regarding the ankle ligament reconstruction-return to sport after injury (ALR-RSI) scale and to assess its correlation with Return to sport and functional outcomes as well as feasibility, reliability and consistency., Methods: A systematic review of the literature based on the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) was conducted using PubMed, Embase and Cochrane Library. Studies that evaluated psychological readiness to return to sport after ankle ligament reconstruction or repair for the treatment of chronic lateral ankle instability using the ALR-RSI scale were included. The results from each study were pooled, and weighted means and overall rates were calculated., Results: In total, 157 patients (53.2% male, mean age: 34.2 years) from three articles were included. Overall, 85.0% of patients reported successful return to sport, but only 48.9% of patients returned to the preoperative sporting level. All studies reported a significant difference in psychological scores between patients who returned to sport and those who did not. Pooled mean patient-reported outcome measures, reported as the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot (AOFAS, three studies) Score and Karlsson-Peterson Score (three studies), were 82.7 (range: 29-100) and 81.7 (range: 25-100), respectively. The ALR-RSI scale demonstrated strong correlations with the AOFAS Score and Karlsson-Peterson Score., Conclusion: Patients who returned to sport after ankle ligament reconstruction or repair exhibited higher psychological readiness compared to those who did not. The ALR-RSI scale showed strong correlations with ankle function. Evaluation of psychological readiness using the ALR-RSI scale may provide an additional tool in the assessment of patients who underwent ankle ligament reconstruction or repair., Level of Evidence: Level III, systematic review., Competing Interests: C. Thomas Haytmanek has received research support from Stryker, consulting fees from Arthrex, speaking fees from Gemini Mountain Medical, Steelhead Surgical, hospitality payments from Integra, Bioventus, Exactech and Stryker, and support for education from Wright Medical Technology. Jonathon D. Backus has received royalties and consulting fees from Medline Unite, holds stock options for Marrow Access Technologies, and is a board and committee member in AOFAS. The remaining authors declare no conflict of interest., (© 2024 The Author(s). Journal of Experimental Orthopaedics published by John Wiley & Sons Ltd on behalf of European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Background: Correction of glenoid retroversion is commonly performed in anatomic total shoulder arthroplasty (TSA) to increase component contact area and decrease eccentric loading of the glenoid component. Despite demonstrated biomechanical advantages, limited information exists on the clinical benefit of correcting glenoid retroversion. The purpose of this systematic review is to critically evaluate the existing literature on the effect of preoperative and postoperative glenoid retroversion on clinical functional and radiologic outcomes in patients who underwent anatomic TSA., Methods: A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses using PubMed, Embase, and Cochrane Library evaluating the impact of glenoid retroversion on clinical and radiologic outcomes of TSA. English-language studies of level I through IV evidence were included. Blinded reviewers conducted multiple screens and methodological quality was appraised using the Modified Coleman Methodology Score., Results: Sixteen studies, including 3 level III and 13 level IV studies (1211 shoulders), satisfied all inclusion criteria. To address glenoid retroversion, 9 studies used corrective reaming techniques, and 4 studies used posteriorly augmented glenoids. Two studies used noncorrective reaming techniques. Mean preoperative retroversion ranged from 12.7° to 24° across studies. Eleven studies analyzed the effect of glenoid retroversion on clinical outcomes, including patient-reported outcome scores (PROs), range of motion (ROM), or clinical failure or revision rates. Most studies (8 of 11) did not report any significant association of pre- or postoperative glenoid retroversion on any clinical outcome. Of the 3 studies that reported significant effects, 1 study reported a negative association between preoperative glenoid retroversion and PROs, 1 study reported inferior postoperative abduction in patients with postoperative glenoid retroversion greater than 15°, and 1 study found an increased clinical failure rate in patients with higher postoperative retroversion. Ten studies reported radiographic results (medial calcar resorption, Central Peg Lucency [CPL] grade, Lazarus lucency grade) at follow-up. Only 1 study reported a significant effect of pre- and postoperative retroversion greater than 15° on CPL grade., Conclusion: There is currently insufficient evidence that pre- or postoperative glenoid version influences postoperative outcomes independent of other morphologic factors such as joint line medialization. Given that noncorrective reaming demonstrated favorable postoperative outcomes, and postoperative glenoid version was not significantly and consistently found to impact outcomes, there is inconclusive evidence that correcting glenoid retroversion is routinely required., (Copyright © 2023 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Objective: The primary goal of this study is to evaluate the relationship between Body Mass Index (BMI) and muscle atrophy in individuals with rotator cuff tears., Methods: This study consists of patients with rotator cuff tears identified by MRI from two independent cohorts, the Rotator Cuff Outcomes Workgroup (ROW) and the Multicenter Orthopaedic Outcomes Network (MOON). Presence of atrophy (yes/no) and severity of atrophy (as an ordinal variable) were assessed on MRI by expert physicians. We used multivariable regression models to evaluate the relationship between BMI and muscle atrophy while adjusting for age and sex in each study, conducted sensitivity analyses for full-thickness tear and combined results using inverse variance-weighted meta-analysis., Results: A total of 539 patients (MOON=395, ROW=144) from the combined cohorts had MRI data available on muscle atrophy. Among these patients, 246 (46%) had atrophy of at least one of the muscles of the rotator cuff and 282 (52%) had full-thickness tears. In meta-analysis across both cohorts, each 5 kg/m 2 increase in BMI was associated with a 21% (aOR=1.21, 95% CI=1.02, 1.43) increased odds of having muscle atrophy among individuals with any tear size, and 36% (aOR=1.36, 95% CI=1.01-1.81) increased odds among individuals with full-thickness tear., Conclusions: Higher BMI was associated with significantly higher odds of muscle atrophy in patiens with rotator cuff tears. More study is needed to unders1tand why and how this relationship exists, as well as whether interventions to reduce BMI may help improve outcomes for these patients., Level of Evidence: III., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)