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Purpose: To investigate the clinical outcomes following arthroscopic chondral nail fixation for acetabular cartilage delamination (ACD) in patients with femoroacetabular impingement syndrome (FAIS), and the presentation of ACD on MRI at follow-up., Methods: A retrospective review was performed between March 2021 and March 2022 at our institute. Patients undergoing primary hip arthroscopy for FAIS and diagnosed with ACD intraoperatively were included. Exclusion criteria were incomplete data or loss of minimum 2-year follow-up, and concomitant hip conditions including hip osteoarthritis with a Tönnis grade > 1, avascular necrosis, Legg-Calvé-Perthes disease, osteoid osteoma, synovial chondromatosis, pigmented villonodular synovitis, and developmental dysplasia of the hip (DDH). Patients who underwent chondral nail fixation were matched 1:1 with a control cohort of patients who only underwent simple debridement. Preoperative and minimum 2-year postoperative patient-reported outcome (PRO) scores including Visual Analog pain Scale (VAS), modified Harris Hip Score (mHHS), and percentage of achieving minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were collected and compared. MRI was performed preoperatively and at final follow-up to assess ACD., Results: Fifty-eight patients were included in the study (29 patients in each group). Both groups demonstrated improved VAS and mHHS following surgery (all with P < .05). The chondral nail group demonstrated better postoperative VAS (P = .022) compared to the control group, while the postoperative mHHS was comparable between the two groups (P = .852). No significant difference was found in the achievement of MCID between the two groups (all with P > .05). More patients in the chondral nail group achieved PASS of VAS compared to the control group (75.9% vs 48.3%, P = .030). No patient underwent revision surgery or conversion to total hip arthroplasty (THA). The chondral nail group demonstrated significantly higher rate of ACD healing on MRI compared to the control group (P < .001)., Conclusion: Patients undergoing arthroscopic chondral nail fixation for treating ACD demonstrated significant pain relief, more achievement of PASS of VAS, and higher rate of ACD healing on MRI compared to those undergoing simple debridement., Level of Evidence: Level III; retrospective cohort study., (Copyright © 2024. Published by Elsevier Inc.)

Purpose: To determine the correlation and classification consistency of femoral version measurements between magnetic resonance (MR) and computed tomography (CT) using 4 commonly used measurement methods., Methods: A retrospective study was performed on patients with femoroacetabular impingement (FAI) who received preoperative CT and MR imaging assessment of the surgical hip and ipsilateral distal femur. Femoral version was measured using the Murphy method, the oblique method, the Reikerås method, and the Lee method. Intra- and inter-rater agreements were calculated. Linear regression and Bland-Altman analysis were performed for measurements using different imaging modalities and measurement methods. Femoral version measurements within the lower quartile, the middle 2 quartiles, and the upper quartile were classified into different groups based on their percentile within the sample population. Classification consistency rates between modalities and methods were calculated and compared., Results: Fifty-three patients (39.4 ± 9.1 years; 32 female) were included for analysis. Intra- and inter-rater reliability were high for all modalities and methods (intrarater intraclass correlation coefficient [ICC] range, 0.963-0.993; inter-rater ICC range, 0.871-0.960). MR- and CT-based femoral version measurements showed strong correlations for all methods, with the Lee method demonstrating the strongest association (r = 0.904), while the oblique method exhibited the lowest correlation (r = 0.684) (all P < .001). MR-based measurements were smaller than CT-based measurements, with mean differences ranging from 4.5° to 10.3°. Classification consistency between MR and CT ranged from 51% to 74%, whereas the consistency between different measurement methods ranged from 68% to 85%., Conclusions: While strong correlations were observed between MR- and CT-based femoral version measurements, MR-based measurements were significantly smaller than their CT counterparts. Classification consistency between the modalities was moderate to high. Measurements between different methods showed strong correlations with high consistency rates., Level of Evidence: Level III, retrospective case series., Competing Interests: Disclosures The authors report the following potential conflicts of interest or sources of funding: Y.X. received funding from the Beijing Municipal Natural Science Foundation (Grant No. Z200003). All other authors (S.Z., K.L., G.G., N.L.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Full ICMJE author disclosure forms are available for this article online, as supplementary material., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate the consecutive changes in effusion-synovitis after primary arthroscopic treatment for patients with femoroacetabular impingement syndrome (FAIS) and to determine the effect of postoperative effusion-synovitis on clinical outcomes., Methods: Data from March 2021 through January 2022 was reviewed. Patients diagnosed with FAIS and undergoing hip arthroscopic treatment were included. Exclusion criteria were incomplete magnetic resonance imaging (MRI) data, prior history of hip surgery, labral reconstruction, and concomitant hip conditions. MRI (noncontrast 3.0 T) was performed preoperatively and 3, 6, and 12 months postoperatively, and the measurement of the largest femoral neck fluid thickness (FTM) and cross-sectional area (CSA) of the effusion-synovitis were collected. Preoperative and a minimum of 2-year postoperative patient-reported outcome (PRO) scores including visual analog scale (VAS), modified Harris Hip Score (mHHS), and International Hip Outcome Tool, 12-component form (iHOT-12) were collected and compared. Postoperative Tegner Activity Scale was also collected. The PROs and achievements of minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were compared between patients with and without postoperative effusion-synovitis. Multivariate linear regression analysis was performed to determine the effect of the effusion-synovitis size on PROs., Results: A total of 61 patients (61 hips) were included in the study. The 3-month postoperative FTM, CSA, and grade of effusion-synovitis presented a significant increase compared with the preoperative values (all P < .05). No significant differences were observed in the 6-month postoperative measurements compared with the preoperative values (all P > .05). At the 12-month follow-up, although there was a significant decrease in all measurements compared with the preoperative values (all P < .001), 39 patients (63.9%) still presented effusion-synovitis. Compared with the other 22 patients (36.1%) without effusion-synovitis, these patients presented inferior mHHS, iHOT-12 (all P < .05), as well as lower achievement of PASS of mHHS (82.1% vs 100%, P = .035) and iHOT-12 (38.5% vs 81.8%, P = .001). The achievement of MCID of mHHS (79.5% vs 77.3%, P = .839) and iHOT-12 (89.7% vs 95.5%, P = .839) were comparable between patients with and without effusion-synovitis. The postoperative sagittal CSA (beta = -.302, P = .039) were negatively related to mHHS in the regression analysis., Conclusions: After arthroscopic treatment for FAIS, the level of effusion-synovitis presented an initial increase, then followed by a subsequent decrease. Effusion-synovitis was significantly alleviated at 12 months compared with the preoperative level. Patients with postoperative effusion-synovitis had inferior clinical outcomes and lower achievement of PASS compared to those without., Level of Evidence: Level IV, retrospective case series., Competing Interests: Disclosures The authors report the following potential conflicts of interest or sources of funding: The Capital Health Research and Development of Special (No. 2022-2Z-40915) and Beijing Natural Science Foundation (No. 7244429)., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To develop a machine-learning model to predict clinical outcomes after medial patellofemoral ligament reconstruction (MPFLR) and identify the important predictive indicators., Methods: This study included patients who underwent MPFLR from January 2018 to December 2022. The exclusion criteria were as follows: (1) concurrent bony procedures, (2) history of other knee surgeries, and (3) follow-up period of less than 12 months. Forty-two predictive models were constructed for 7 clinical outcomes (failure to achieve minimum clinically important difference of clinical scores, return to preinjury sports, pivoting sports, and recurrent instability) using 6 machine-learning algorithms (random forest, logistic regression, support vector machine, decision tree, implemented multilayer perceptron, and K-nearest neighbor). The performance of the model was evaluated using metrics such as the area under the receiver operating characteristic curve, accuracy, specificity, and sensitivity. In addition, SHapley Additive exPlanation summary plot was employed to identify the important predictive factors of the best-performing model., Results: A total of 218 patients met criteria. For the best-performing models in predicting failure to achieve the minimum clinically important difference for Lysholm, International Knee Documentation Committee, Kujala, and Tegner scores, the area under the receiver operating characteristic curves and accuracies were 0.884 (good) and 87.3%, 0.859 (good) and 86.2%, 0.969 (excellent) and 97.0%, and 0.760 (fair) and 76.8%, respectively; 0.952 (excellent) and 95.2% for return to preinjury sports; 0.756 (fair) and 75.4% for return to pivoting sports; and 0.943 (excellent) and 94.9% for recurrent instability. Low preoperative Tegner score, shorter time to surgery, and absence of severe trochlear dysplasia were significant predictors for return to preinjury sports, whereas the absence of severe trochlear dysplasia and patellar alta were significant predictors for return to pivoting sports. Older age, female sex, and low preoperative Lysholm score were highly predictive of recurrent instability., Conclusions: The predictive models developed using machine-learning algorithms can reliably forecast the clinical outcomes of MPFLR, particularly demonstrating excellent performance in predicting recurrent instability., Level of Evidence: Level III, case-control study., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To enhance the understanding of histologic healing after repairing medial meniscal posterior root tears (MMPRTs) at an early stage, utilizing a goat model., Methods: Eighteen adult goats, totaling 36 knee joints, were allocated into 3 groups (n = 12): sham group (Sham), root tear group (RT), and root tear with transosseous suture group (RTS). At 12- and 24-week intervals postsurgery, all the knees were harvested for imaging, macroscopic, histologic, and biomechanical assessments., Results: The intact root served as a meniscus-bone interface that connected the tibial and circular fibers of the meniscus with a bony insertion and a root-meniscus transition. A direct fibrous connection was displayed at the bony insertion proximal to the synovium in the RTS group, while the remaining regions of the root displayed indirect fibrous healing. The healing in the RT group was disjointed and reminiscent of scar tissue. The RTS group exhibited a more pronounced coronal extrusion compared to the Sham group (0.42 ± 0.09 vs 0.19 ± 0.02, P = .0012) but was improved relative to that of the RT group (0.49 ± 0.02, P = .0028). The failure load and stiffness of the RTS group were notably higher than those of the RT group, with a strength of 42.67% and a stiffness of 83.75% of the intact root. All the samples ruptured at the root-meniscus transitions., Conclusions: The incomplete healing may be attributed to the histologic factors underlying the low healing rate and persistent medial meniscal extrusion. Notably, the region attached to the posterior cruciate ligament exhibited superior healing compared to other regions of the bony insertion in the repaired group. Conversely, the root-meniscus transition displayed discontinuity, representing a mechanical weakness in the healing process., Clinical Relevance: Modifications of bone tunnel positioning and suture placement could be undertaken in subsequent studies to enhance the healing of the root-meniscus transition., Competing Interests: Disclosures The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This study was supported by National Natural Science Foundation of China (82022046, 82172416), Natural Science Foundation of Guangdong Province (2020B1515020014, 2022A1515011714, 2022A1515010215), Guangdong Basic and Applied Basic Research Foundation (2021A1515012337), Guangdong Science and Technology Collaborative Innovation Center for Sports (2019B110210004), and Fundamental Research Funds for the Central Universities (23xkjc006). All authors (X-H.D., J-S.W., Z.C., W-K.Z., H-M.P., W-T.Y., C.J., B.S., W-P.L., Z-Z.Z.) 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 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the biomechanical effects of augmenting Bankart repair (BR) with either remplissage or dynamic anterior stabilization (DAS) in the treatment of anterior shoulder instability with on-track or off-track bipolar bone loss., Methods: Eight fresh-frozen cadaveric shoulders were tested at 60° of glenohumeral abduction in the intact, injury, and repair conditions. Injury conditions included 15% glenoid bone loss with an on-track or off-track Hill-Sachs lesion as previously recommended. Repair conditions included isolated BR, BR with remplissage, and BR with DAS (long head of biceps transfer). The glenohumeral stability was assessed by measuring the anterior translation under 0, 10, 20, 30, 40, 50 N load and maximum load without causing instability at mid-range (60°) and end-range (90°) external rotation (ER). Maximum range of motion (ROM) was measured by applying a 2.2-N·m torque in passive ER and internal rotation., Results: Isolated BR failed to restore native glenohumeral stability in both on-track and off-track bipolar bone loss models. Both remplissage and DAS significantly decreased the anterior instability in the bipolar bone loss models, showing better restoration than the isolated BR. In the on-track lesions, DAS successfully restored native glenohumeral stability and mobility, whereas remplissage significantly decreased anterior translation without load (-2.12 ± 1.07 mm at 90° ER, P = .003; -1.98 ± 1.23 mm at 60° ER, P = .015). In the off-track lesions, remplissage restored native glenohumeral stability but led to significant ROM limitation (-8.6° ± 2.3° for internal rotation, P < .001; -13.9° ± 6.2° for ER, P = .003), whereas DAS failed to restore native stability at 90° ER regarding the increased anterior translation under 50 N (4.10 ± 1.53 mm, P < .001) and decreased maximum load (-13.8 ± 9.2 N, P = .021)., Conclusions: At time-zero, both remplissage and DAS significantly reduced residual anterior instability compared with isolated BR in the bipolar bone loss models and restored the native glenohumeral stability under most translational loads. However, remplissage could decrease the anterior translation without load for on-track lesions and may restrict ROM for off-track lesions, whereas DAS failed to restore native stability under high translational loads for off-track lesions., Clinical Relevance: DAS could be recommended to treat on-track bipolar bone loss with less biomechanical adverse effects, whereas remplissage might be the preferred procedure to address off-track bipolar bone loss for better stability., Competing Interests: Disclosures The authors report the following potential conflicts of interest or sources of funding: Funded by the National Natural Science Foundation of China (Grant No. 82272579 and 31972923). All other authors (C.W., Z.Y., S.L., Z.F., J.X., J.Z.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Full ICMJE author disclosure forms are available for this article online, as supplementary material., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To develop a deep learning (DL) model that can simultaneously detect lateral and medial collateral ligament injuries of the ankle, aiding in the diagnosis of chronic ankle instability (CAI), and assess its impact on clinicians' diagnostic performance., Methods: DL models were developed and externally validated on retrospectively collected ankle magnetic resonance imaging (MRI) between April 2016 and March 2022 respectively at 3 centers. Included patients had confirmed diagnoses of CAI through arthroscopy, as well as individuals who had undergone MRI and physical examinations that ruled out ligament injuries. DL models were constructed based on a multilabel paradigm. A transformer-based multilabel DL model (AnkleNet) was developed and compared with 4 convolution neural network (CNN) models. Subsequently, a reader study was conducted to evaluate the impact of model assistance on clinicians when diagnosing challenging cases: identifying rotational CAI (RCAI). Diagnostic performance was assessed using area under the receiver operating characteristic curve (AUC)., Results: Our transformer-based model achieved AUCs of 0.910 and 0.892 for detecting lateral and medial collateral ligament injury, respectively, both of which were significantly higher than those of CNN-based models (all P < .001). In terms of further CAI diagnosis, there was a macro-average AUC of 0.870 and a balanced accuracy of 0.805. The reader study indicated that incorporation with our model significantly enhanced the diagnostic accuracy of clinicians (P = .042), particularly junior clinicians, and led to a reduction in diagnostic variability. The code of the model can be accessed at https://github.com/ChiariRay/AnkleNet., Conclusions: Our transformer-based model was able to detect lateral and medial collateral ligament injuries based on MRI and outperformed CNN-based models, demonstrating a promising performance in diagnosing CAI, especially patients with RCAI., Clinical Relevance: Developing such an algorithm can improve the diagnostic performance of clinicians, aiding in identifying patients who would benefit from arthroscopy, such as patients with RCAI., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the patient-reported outcomes and radiologic outcomes of the patients with medial and lateral cystic osteochondral lesions of the talus (OLTs) following bone marrow stimulation (BMS)., Methods: Patients with cystic OLTs who underwent BMS between January 2016 and February 2021 were retrospectively analyzed, and the minimum follow-up time was more than 24 months. Patients were paired in a 1:1 ratio (medial cystic OLT [MC-OLT]/lateral cystic OLT [LC-OLT]) based on the OLT area within 30 mm 2 , follow-up within 1 year, age within 5 years, and ligament surgery (yes/no). The visual analog scale and Foot and Ankle Ability Measure (FAAM)-Activities of Daily Life and Sports scores were assessed preoperatively and postoperatively. The magnetic resonance observation of cartilage repair tissue scores and presence of cysts after BMS were also evaluated. Additionally, the receiver operating characteristic curve was performed., Results: The matched patients were divided into the MC-OLT (n = 31, 43.35 ± 12.32 months) and LC-OLT groups (n = 31, 43.32 ± 14.88 months, P = .986). Thirty patients of each group achieved a power of 80% and an α = 0.05 in this study. The MC-OLT group showed significantly less improvement in FAAM-Activities of Daily Life and sports scores (P = .034, P < .001, respectively), lower magnetic resonance observation of cartilage repair tissue scores (80.80 ± 11.91 vs 86.00 ± 8.50, P = .010), and higher presence rate of cysts after BMS (45.16% vs 16.12%, P = .013). Regarding FAAM sports scores, the LC-OLT group had significantly more patients exceeding the minimal clinically important difference (80.64% vs 51.61%, P = .031). Furthermore, an OLT depth of 7.23 mm (sensitivity: 78.6%; specificity: 70.6%) might serve as a cutoff value for predicting the presence of cysts in medial cystic OLTs following BMS., Conclusions: Medial cystic OLTs exhibited markedly lower sports levels, higher cyst presence rate, and inferior radiologic outcomes following BMS than lateral counterparts. Additionally, an OLT depth of 7.23 mm could be the cutoff value for predicting the presence of cysts regarding medial cystic OLTs after BMS., Level of Evidence: Level III, retrospective comparative study., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess the postoperative outcomes of double-level knee derotational osteotomy (KDRO) combined with medial patellofemoral ligament reconstruction (MPFLR) and to compare it with tibial tuber transfer (TTT) and MPFLR without derotational osteotomy in patients with recurrent patellar instability and a marked torsional deformity., Methods: From March 2020 to December 2021, patients with torsion deformity (combined femoral torsion [FT] and tibial torsion [TTn] ≥30°) were retrospectively included. The minimum follow-up time was 18 months. Patients who received KDRO and MPFLR were categorized as the KDRO group and patients who received a combined TTT and MPFLR were categorized as the control group. Preoperative and postoperative clinical symptoms, patient-reported outcomes (Kujala, visual analog scale, Lysholm, International Knee Documentation Committee, Tegner, and Knee Injury and Osteoarthritis Outcome scores), and imaging parameters (FT, TTn, patellar height, femoral trochlear dysplasia, congruence angle, patellar tilt angle, lateral patellar angle, lateral patellar translation, and tibial tubercle-trochlear groove distance) were analyzed., Results: In all, 36 patients were included with 18 in KDRO group and 18 in control group. The mean follow-up time was 30 (range 21-39) months. At the latest follow-up, no patient experienced redislocation in either group. Except for the FT and TTn in the control group, postoperative imaging parameters were significantly reduced to the normal range. KDRO group had a lower patellar tilt angle (P = .043, effect size 0.64). All clinical scores in both groups significantly improved postoperatively. The KDRO group had better functional scores than control group except the KOOS daily living activities subscore and the KOOS sports and recreation subscore. More patients in the KDRO group met the minimal clinically important difference for most patient-reported outcomes than the control group. Eight patients (44%) in the control group complained of postoperative anterior knee pain, compared with 1 patient (6%) in the KDRO group (P = .018)., Conclusions: KDRO combined with MPFLR was associated with better postoperative outcomes than TTT combined with MPFLR in patients with recurrent patellar instability and a torsion deformity., Level of Evidence: Level III, retrospective cohort study., Competing Interests: Disclosures The authors report the following potential conflicts of interest or sources of funding: supported by the National Natural Science Foundation of China (grant number 82272579); Basic Research Program of Shanghai Sixth People’s Hospital (grant number YNMS202105); the Shanghai Science and Technology Committee (22dz1204700); and Exploratory Research Program of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital (grant number YNTS202001). 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. Full ICMJE author disclosure forms are available for this article online, as supplementary material., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate whether the modified suture-button Latarjet procedure with coracoacromial ligament (CAL) and pectoralis minor (PM) preservation could achieve excellent outcomes at the 2-year follow-up., Methods: During January 2019 to January 2021, the data of patients who underwent modified suture-button Latarjet with CAL and PM preservation in our department were collected. The glenoid bone loss of these patients was greater than 20% or greater than 10% with high demands for exercise. Partial coracoid osteotomy was based on the results of a preoperative 3-dimensional computed tomography evaluation of the glenoid defect area and corresponding coracoid process morphology. The preoperative and postoperative clinical results were assessed. The minimal clinically important difference (MCID) was used to compare improvement in clinical outcomes. Graft-glenoid union and remodeling were assessed using postoperative 3-dimensional computed tomography, and magnetic resonance imaging was performed to confirm the integrity of the CAL and PM postoperatively., Results: In total, 35 patients were included in this study; the mean follow-up time was 26.9 ± 1.9 months. No case of recurrent dislocation or sublaxity. Significant improvements were observed in mean visual analog scale (VAS) scores for pain during motion, American Shoulder and Elbow Surgeons (ASES) score, Rowe score, and Walch-Duplay score (P < .001). The percentage of patients achieving at least an MCID improvement in clinical outcomes was VAS 85.71%, ASES 97.14%, Rowe 100%, and Walch-Duplay 97.14%. Thirty-three patients (94.3% of all cases) were able to return to their preoperative sport levels, 34 grafts (97.1%) achieved bone union (1 soft union) in 6.3 ± 2.2 months, and the coracoid grafts restored 97.1 ± 4.0% of the perfect-fitting circle at the last follow-up. Postoperative computed tomography scan showed that 31 grafts (88.6%) were placed ideally in vertical view. In the axial view, 25 grafts (82.9%) were flushed to the glenoid, whereas 1 and 5 grafts were fixed medially and laterally, respectively. The CAL and PM were visualized postoperatively. No arthropathy was observed in any patient at the last follow-up., Conclusions: The modified suture-button Latarjet procedure with CAL and PM preservation obtained good clinical and radiological results without recurrence or complications. A substantial number of patients (>85%) achieved the MCID for the VAS, ASES, Rowe, and Walch-Duplay scores. In addition, the malpositioned graft (17.1%) did not cause arthropathy of the joints at 2-year follow-up., Level of Evidence: Level IV, retrospective case series., Competing Interests: Disclosures The authors (W.L. D.L., Y.L., B.W., Z.L., J.S., H.L., X.L., Z.D.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. This study was supported by the National Natural Science Foundation of China (No. 82072515), Guangdong Basic and Applied Basic Research Foundation (2023A1515220072, 2021A1515220030), and Start-up Funding for Talented Scientific Research of the First Affiliated Hospital of Wenzhou Medical University (2023QD026)., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Orthoregeneration is defined as a solution for orthopaedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and, optimally, provide an environment for tissue regeneration. Options include drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electromagnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the elbow and upper extremity, including the tendons (lateral epicondylitis, medial epicondylitis, biceps tendonitis, triceps tendonitis), articular cartilage (osteoarthritis, osteochondral lesions), and bone (fractures, nonunions, avascular necrosis, osteonecrosis). Promising and established treatment modalities include hyaluronic acid; botulinum toxin; corticosteroids; leukocyte-rich and leukocyte-poor platelet-rich plasma; autologous blood; bone marrow aspirate comprising mesenchymal stromal cells (alternatively termed medicinal signaling cells and frequently mesenchymal stem cells [MSCs]) and bone marrow aspirate concentrate; MSCs harvested from adipose and skin (dermis) sources; vascularized bone grafts; bone morphogenic protein scaffold made from osteoinductive and conductive β-tricalcium phosphate and poly-ε-caprolactone with hydrogels, human MSCs, and matrix metalloproteinases; and collagen sponge. Autologous blood preparations such as autologous blood injections and platelet-rich plasma show positive outcomes for nonresponsive tendinopathy. In addition, cellular therapies such as tissue-derived tenocyte-like cells and MSCs show a promising ability to regulate degenerative processes by modulating tissue response to inflammation and preventing continuous degradation and support tissue restoration., Competing Interests: Disclosures All authors (T.L., F.T., Z.S., P.P.R., and S.C-R.) 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 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate the association between lateral femoral condyle ratio (LFCR) measured by magnetic resonance imaging (MRI) and anterior cruciate ligament (ACL) rerupture after anatomic ACL reconstruction (ACLR) and to compare the diagnostic accuracy between MRI and radiograph measurements., Methods: A retrospective review was conducted on patients who underwent anatomic ACLR in our institution between 2015 and 2018. Patients who experienced rerupture after ACLR were identified and matched 1:1 with control patients who showed no evidence of graft failure during a minimum 48-month follow-up. The matching criteria included age, sex, and body mass index. LFCR was measured on MRI scans and radiographs of the affected limb. Patients' characteristics, surgical features, and anatomic measurements were compared between groups. Conditional logistic regression was performed to investigate whether MRI-measured LFCR is a risk factor for ACL rerupture. The optimal cutoff value was determined by receiver operating characteristic curves (ROC). Delong's test was performed to compare the diagnostic accuracy between MRI and radiograph measurements., Results: A total of 72 patients who sustained ACL rerupture were included and matched with 72 control subjects. Compared to patients with intact ACLR, those who sustained ACL rerupture showed a significant increase in LFCR on MRI scans (63.38% ± 2.26% [95% CI, 62.84%-63.91%] vs 61.10% ± 2.19% [95% CI, 60.59%-61.61%], P < .001). An MRI-measured LFCR >62.18% was set as the cutoff point to discern patients at a higher risk of graft failure after anatomic ACLR, with sensitivity and specificity of 75.0% and 70.8%, respectively. MRI-measured LFCR demonstrated superior diagnostic accuracy during ROC curve analysis, achieving a higher area under the curve compared to radiograph-measured LFCR (0.783 ± 0.051 vs 0.668 ± 0.060, P = .041)., Conclusions: The study found that MRI-measured LFCR was associated with ACL rerupture. A cutoff value of 62.18% was determined, which can help identify patients at a higher risk of rerupture., Level of Evidence: Level III, retrospective comparative study., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: (1) To determine the effect of concomitant ipsilateral knee pain (IKP) on short-term outcomes after hip arthroscopic treatment of femoroacetabular impingement syndrome (FAIS) and (2) to determine whether IKP would improve with surgery., Methods: Data between September 2021 and May 2022 were reviewed. Patients with a diagnosis of FAIS who underwent hip arthroscopy with a minimum of 1-year follow-up were included. The exclusion criteria were prior ipsilateral hip or knee surgery, hip Tönnis grade greater than 1, knee Kellgren-Lawrence grade greater than 2, hip conditions (avascular necrosis, Legg-Calvé-Perthes disease, pigmented villonodular synovitis, osteoid osteoma, synovial chondromatosis, and developmental dysplasia of the hip), and spine diseases. All patients underwent knee magnetic resonance imaging preoperatively. Preoperative and short-term (1-year) patient-reported outcomes were collected, consisting of the Hip Sports Activity Scale score, weekly sports participation, modified Harris Hip Score (mHHS), 12-component International Hip Outcome Tool (iHOT-12) score, and visual analog pain scale (VAS) scores for the hip and the ipsilateral knee. The percentages of patients achieving the minimal clinically important difference and patient acceptable symptom state (PASS) for the mHHS and iHOT-12 score were calculated. Multivariate regression analysis was performed to determine the effect of IKP severity on postoperative outcomes. Subgroup analysis was performed between patients with IKP alleviation and those without IKP alleviation., Results: Among the 107 patients included, 47 presented with preoperative IKP. Compared with patients without IKP, the IKP cohort had comparable knee structural abnormalities (all with P > .05). Still, the IKP cohort showed inferior preoperative values for the mHHS (P = .003), iHOT-12 score (P = .016), hip VAS score (P = .001), and weekly sports participation (P = .039). Postoperatively, the IKP cohort had a lower mHHS (P = .046), lower iHOT-12 score (P = .037), and lower hip VAS score (P = .003) and were less likely to achieve the PASS for the mHHS (P = .021) and iHOT-12 score (P = .049). Patients with higher knee VAS scores were less likely to achieve the PASS for the mHHS (odds ratio, 0.61; P = .023). Within the IKP group, the knee VAS score improved from 2.3 to 1.0 (P < .001). Patients with alleviated IKP showed superior postoperative iHOT-12 scores (P = .038) compared with patients with persistent IKP., Conclusions: Concomitant IKP at baseline negatively affected preoperative status and short-term clinical outcomes after arthroscopic treatment of FAIS. Patients with IKP were less likely to meet clinical thresholds. Most patients achieved IKP alleviation postoperatively, which was associated with superior clinical outcomes., Level of Evidence: Level III, retrospective cohort study., Competing Interests: Disclosures The authors report no conflicts of interest in the authorship and publication of this article. Full ICMJE author disclosure forms are available for this article online, as supplementary material., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare clinical and radiographic outcomes of medial patellofemoral ligament reconstruction (MPFL-R) and medial patellofemoral complex reconstruction (MPFC-R) for recurrent patellar dislocation. Outcome measures were compared based on the Insall-Salvati index., Methods: Patients who were diagnosed with recurrent patellar dislocation and underwent either MPFL-R or MPFC-R (combined reconstruction of MPFL and medial quadriceps tendon-femoral ligament) were retrospectively analyzed. Group allocation was based on surgical procedure and patient characteristics were collected. Clinical assessments included patient-reported outcome measures (PROMs) and return-to-sports rates. Minimal clinically important difference analysis was performed. A subgroup analysis of PROMs was carried out between patients with an Insall-Salvati index ≤1.2 versus >1.2. The patellar tilt angle, lateral patellar displacement, and bisect offset ratio were measured pre- and postsurgery. Functional failures and complications were assessed., Results: Overall, 70 patients (72 knees) in the MPFL-R group and 58 patients (61 knees) in the MPFC-R group were included. Patient characteristics were comparable between the groups. At a minimum follow-up of 24 (mean, 50.6 ± 22.1) months, all PROMs were substantially improved (P < .001), without significant intergroup differences. The percentages of patients reaching the minimal clinically important difference were similar after MPFL-R and MPFC-R: 98.6% versus 93.4% (International Knee Documentation Committee), 97.2% versus 98.4% (Lysholm), 98.6% versus 100% (Kujala), and 77.8% versus 72.1% (Tegner). The subgroup analysis based on patellar height and the return-to-sport rates also suggested comparable results. Radiographic evaluation demonstrated significantly smaller lateral patellar displacements (P = .004) and bisect offset ratios (P < .001) but similar patellar tilt angles after MPFC-R. Four (5.6%) patients receiving MPFL-R and 2 (3.3%) patients receiving MPFC-R reported recurrence of functional instability, without statistically significant difference., Conclusions: MPFC-R resulted in similar overall clinical and radiographic outcomes to MPFL-R in treating recurrent patellar dislocation. MPFC-R might not provide additional benefits for patients with an Insall-Salvati index >1.2., Level of Evidence: Level IV, therapeutic, retrospective cohort study., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To develop a deep learning model to accurately detect anterior cruciate ligament (ACL) ruptures on magnetic resonance imaging (MRI) and to evaluate its effect on the diagnostic accuracy and efficiency of clinicians., Methods: A training dataset was built from MRIs acquired from January 2017 to June 2021, including patients with knee symptoms, irrespective of ACL ruptures. An external validation dataset was built from MRIs acquired from January 2021 to June 2022, including patients who underwent knee arthroscopy or arthroplasty. Patients with fractures or prior knee surgeries were excluded in both datasets. Subsequently, a deep learning model was developed and validated using these datasets. Clinicians of varying expertise levels in sports medicine and radiology were recruited, and their capacities in diagnosing ACL injuries in terms of accuracy and diagnosing time were evaluated both with and without artificial intelligence (AI) assistance., Results: A deep learning model was developed based on the training dataset of 22,767 MRIs from 5 centers and verified with external validation dataset of 4,086 MRIs from 6 centers. The model achieved an area under the receiver operating characteristic curve of 0.987 and a sensitivity and specificity of 95.1%. Thirty-eight clinicians from 25 centers were recruited to diagnose 3,800 MRIs. The AI assistance significantly improved the accuracy of all clinicians, exceeding 96%. Additionally, a notable reduction in diagnostic time was observed. The most significant improvements in accuracy and time efficiency were observed in the trainee groups, suggesting that AI support is particularly beneficial for clinicians with moderately limited diagnostic expertise., Conclusions: This deep learning model demonstrated expert-level diagnostic performance for ACL ruptures, serving as a valuable tool to assist clinicians of various specialties and experience levels in making accurate and efficient diagnoses., Level of Evidence: Level III, retrospective comparative case series., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the histologic healing process and mechanical characteristics of the interface between a fascia lata autograft and supraspinatus muscle by establishing a supraspinatus tendon reconstruction model for chronic massive irreparable rotator cuff tears (MIRCTs)., Methods: A total of 40 rats were studied. Eight rats were killed to establish an intact control group, and the other rats were first established as a chronic MIRCT model and then developed as the supraspinatus tendon reconstruction model. Histology, fatty infiltration, mechanics, and open field test for the interface between the fascia lata autograft and muscle were assessed at 2, 4, 8, and 16 weeks postoperatively., Results: Histologically, the interface between the fascia lata autograft and muscle gradually regenerated structural characteristics similar to the normal muscle-tendon interface by 16 weeks postoperatively. The amount of collagen I and III increased significantly during the healing time and stabilized at 8 weeks postoperatively. Fatty infiltration was obvious in the supraspinatus muscle 4 weeks after establishing the MIRCT model. However, the degree of fatty infiltration in the supraspinatus muscle gradually decreased after supraspinatus tendon reconstruction and stabilized at 8 weeks postoperatively. The ultimate failure force and ultimate stress gradually increased from 2 to 16 weeks and reached the level of the intact control tendon at 16 weeks postoperatively (P = .086). The movability of the forepaw returned to normal in the open field test (P = .907)., Conclusions: In this rat supraspinatus tendon reconstruction model, fascia lata autografts showed good interface healing with the supraspinatus muscle, and fatty infiltration in the supraspinatus muscle was histologically decreased. The interface between the fascia lata autograft and muscle showed mechanical strength similar to the anatomic muscle-tendon interface., Clinical Relevance: A supraspinatus tendon reconstruction technique using fascia lata autografts might be a good histologic and biomechanical option for treating MIRCTs., Competing Interests: Disclosures The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: This study was supported by the Chongqing Yingcai Projects for Creative Leading Talents (CQYC20200303135) and Chongqing Natural Science Fund (2023NSCQ-MS-X2660)., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To perform a Delphi consensus for on-field and pitch-side assessment of sports-related concussion (SRC)., Methods: Open-ended questions in rounds 1 and 2 were answered. The results of the first 2 rounds were used to develop a Likert-style questionnaire for round 3. If agreement at round 3 was ≤80% for an item, if panel members were outside consensus, or there were >30% neither agree/disagree responses, the results were carried forward into round 4. The level of agreement and consensus was defined as 90%., Results: Loss of consciousness (LOC) or suspected LOC, motor incoordination/ataxia, balance disturbance, confusion/disorientation, memory disturbance/amnesia, blurred vision/light sensitivity, irritability, slurred speech, slow reaction time, lying motionless, dizziness, headaches/pressure in the head, falling to the ground with no protective action, slow to get up after a hit, dazed look, and posturing/seizures were clinical signs of SRC and indicate removal from play. Video assessment is helpful but should not replace clinical judgment. LOC/unresponsiveness, signs of cervical spine injury, suspicion of other fractures (skull/maxillo-facial), seizures, Glasgow Coma Scale score <14 and abnormal neurologic examination findings are indications for hospitalization. Return to play should only be considered when no clinical signs of SRC are present. Every suspected concussion should be referred to an experienced physician., Conclusions: Consensus was achieved for 85% of the clinical signs indicating concussion. On-field and pitch-side assessment should include the observation of the mechanism, a clinical examination, and cervical spine assessment. Of the 19 signs and red flags requiring removal from play, consensus was reached for 74%. Normal clinical examination and HIA with no signs of concussion allow return to play. Video assessment should be mandatory for professional games but should not replace clinical decision-making. Sports Concussion Assessment Tool, Glasgow Coma Scale, vestibular/ocular motor screening, Head Injury Assessment Criteria 1, and Maddocks questions are useful tools. Guidelines are helpful for non-health professionals., Level of Evidence: Level V, expert opinion., (Copyright © 2023 Arthroscopy Association of North America. All rights reserved.)

Purpose: To perform a Delphi consensus for return to sports (RTS) following sports-related concussion (SRC)., Methods: Open-ended questions in rounds 1 and 2 were answered. The results of the first 2 rounds were used to develop a Likert-style questionnaire for round 3. If agreement at round 3 was ≤80% for an item, if panel members were outside consensus or there were >30% neither agree/disagree responses, the results were carried forward into round 4. The level of agreement and consensus was defined as 90%., Results: Individualized graduated RTS protocols should be used. A normal clinical, ocular and balance examination with no more headaches, and asymptomatic exertional test allows RTS. Earlier RTS can be considered if athletes are symptom free. The Sports Concussion Assessment Tool 5 and vestibular and ocular motor screening are recognized as useful tools to assist in decision-making. Ultimately RTS is a clinical decision. Baseline assessments should be performed at both collegiate and professional level and a combination of neurocognitive and clinical tests should be used. A specific number of recurrent concussions for season-or career-ending decisions could not be determined but will affect decision making for RTS., Conclusions: Consensus was achieved for 10 of the 25 RTS criteria: early RTS can be considered earlier than 48 to 72 hours if athletes are completely symptom-free with no headaches, a normal clinical, ocular and balance examination. A graduated RTS should be used but should be individualized. Only 2 of the 9 assessment tools were considered to be useful: Sports Concussion Assessment Tool 5 and vestibular and ocular motor screening. RTS is mainly a clinical decision. Only 31% of the baseline assessment items achieved consensus: baseline assessments should be performed at collegiate and professional levels using a combination of neurocognitive and clinical tests. The panel disagreed on the number of recurrent concussions that should be season- or career-ending., Level of Evidence: Level V, expert Opinion., (Copyright © 2023 Arthroscopy Association of North America. All rights reserved.)

Purpose: To evaluate the safety and efficacy of a next-generation, all-suture anchor in patients undergoing arthroscopic repair of rotator cuff tears, compared with that of an established solid suture anchor., Methods: Between April 2019 and January 2021, a prospective, comparative, randomized controlled noninferiority study conducted on people with Chinese ethnicity at 3 tertiary hospitals enrolled patients (18-75 years) requiring arthroscopic treatment for rotator cuff tears. Patients were randomized into 2 cohorts receiving either all-suture anchor or solid suture anchor and followed for 12 months. The primary outcome was the Constant-Murley score at the 12-month follow-up. Magnetic resonance imaging assessments determined the rate of retear of rotator cuff repair (defined as Sugaya classification 4 and 5). Safety evaluation was performed at all follow-up points to determine the adverse events (AEs)., Results: In total, 120 patients with rotator cuff tears (mean age, 58.3 years; 62.5% female; 60 receiving all-suture anchor) underwent treatment. Five patients were lost to follow-up. Both cohorts showed significant improvement in Constant-Murley scores between baseline and 6 months (P < .001) and between 6 and 12 months (P < .001). There were no significant differences in Constant-Murley scores between the 2 cohorts at 12 months (P = .122) after operation. The retear rate at 12 months was 5.7% and 1.9% in the all-suture and solid suture anchor cohorts, respectively (P = .618). There were 2 cases of intraoperative anchor pullout, both of which were successfully resolved. No cases of postoperative reoperation or other anchor-related AEs were reported., Conclusions: The all-suture anchor offered equivalent clinical performance to an established solid suture anchor at the 12-month follow-up in patients undergoing arthroscopic repair of rotator cuff tears. The retear rate was not statistically significantly different between the 2 cohorts., Level of Evidence: Level I, randomized controlled trial., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To identify risk factors for patients who sustain nontraumatic anterior cruciate ligament reconstruction (ACLR) failure., Methods: A retrospective analysis was performed on patients undergoing primary or revision ACLR in our institution between 2010 and 2018. Patients sustaining insidious-onset knee instability without history of trauma were identified as nontraumatic ACLR failure and assigned to the study group. The control group of subjects who showed no evidence of ACLR failure with minimum 48-month follow-up were matched in a 1:1 ratio based on age, sex, and body mass index. Anatomic parameters including tibial slope (lateral [LTS], medial [MTS]); tibial plateau subluxation (lateral [LTPsublx], medial [MTPsublx]); notch width index (NWI); and lateral femoral condyle ratio were measured with magnetic resonance imaging or radiography. Graft tunnel position was assessed using 3-dimensional computed tomography and reported in 4 dimensions: deep-shallow ratio (DS ratio) and high-low ratio for femoral tunnel, anterior-posterior ratio and medial-lateral ratio for tibial tunnel. Interobserver and intraobserver reliability were evaluated by the intraclass correlation coefficient (ICC). Patients' demographic data, surgical factors, anatomic parameters, and tunnel placements were compared between the groups. Multivariate logistic regression and receiver operating characteristic curve analysis was used to discriminate and assess the identified risk factors., Results: A total of 52 patients who sustained nontraumatic ACLR failure were included and matched with 52 control subjects. Compared to patients with intact ACLR, those who sustained nontraumatic ACLR failure showed significantly increased LTS, LTPsublx, MTS, and deceased NWI (all P < .001). Moreover, the average tunnel position in the study group was significantly more anterior (P < .001) and superior (P = .014) at the femoral side and more lateral (P = .002) at the tibial side. Multivariate regression analysis identified LTS (odds ratio [OR] = 1.313; P = .028), DS ratio (OR = 1.091; P = .002), and NWI (OR = 0.813; P = .040) as independent predictors of nontraumatic ACLR failure. LTS appeared to be the best independent predictive factor (area under the curve [AUC] = 0.804; 95% confidence interval [CI], 0.721-0.887), followed by DS ratio (AUC = 0.803; 95% CI, 0.717-0.890), and NWI (AUC = 0.756; 95% CI, 0.664-0.847). The optimal cutoff values were 6.7° for increased LTS (sensitivity = 0.615, specificity = 0.923); 37.4% for increased DS ratio (sensitivity = 0.673, specificity = 0.885); and 26.4% for decreased NWI (sensitivity = 0.827, specificity = 0.596). Intraobserver and interobserver reliability was good to excellent, with ICCs ranging from 0.754 to 0.938 for all radiographical measurements., Conclusions: Increased LTS, decreased NWI, and femoral tunnel malposition are predictive risk factors for nontraumatic ACLR failure., Level of Evidence: Level III, retrospective comparative study., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate the efficacy of all-arthroscopic glenoid bone augmentation surgery using the iliac crest autograft procedure. Furthermore, we sought to compare the clinical and radiographic outcomes of using screw versus button fixation, in patients with recurrent anterior shoulder instability., Methods: Between 2015 and 2019, 134 shoulders with persistent instability were surgically treated with an arthroscopically placed autologous iliac crest bone graft transfer procedure. Preoperative and postoperative clinical follow-up data were evaluated using the range of motion, and the Walch-Duplay, American Shoulder and Elbow Society, and Rowe scores. Radiologic assessment on 3-dimensional computed tomography scans was performed preoperatively, immediately after surgery, as well as postoperatively, at 3 months, 6 months, 1 year, and at the final follow-up stage. Graft positions, healing, and resorption were evaluated from postoperative images., Results: This study included 102 patients who underwent arthroscopic iliac crest bone grafting procedure with 2 screws fixation (n = 37; group 1) and 2 button fixation (n = 65; group 2). The mean follow-up period was 37 months. There were no significant differences between groups in terms of clinical scores, shoulder motion range, graft healing, or graft positions on computed tomography scans (P>.05). In group 1, 1 patient showed mechanical irritation and persistent pain around the screw insertion site, being treated through the arthroscopic removal of the screws. The average postoperative bony resorption percentages were 20.3% and 11.2% at 6 months, and 32.4% and 19.3% at 12 months, in group 1 and group 2, respectively. A statistically significant difference was detected between the two groups (P<.05)., Conclusions: In the arthroscopic iliac crest bone grafting procedure for the treatment of chronic osseous anterior shoulder instability, excellent functional results were obtained after both button fixation and screw fixation techniques. In addition, less graft resorption and no hardware-related complications were detected with suture button fixation technique., Level of Evidence: Level III, retrospective comparative therapeutic trial., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: To measure femoral torsion on computed tomography images in patients with femoroacetabular impingement syndrome and explore whether femoral torsion was significantly correlated with anterior capsular thickness., Methods: Prospectively collected data of surgical patients were retrospectively reviewed. Only patients aged 16 to 55 years who underwent primary hip surgery were included in this study. Patients with a history of revision hip surgery, previous knee surgery, hip dysplasia, hip synovitis, and/or incomplete radiographs and medical records were excluded from the study. Femoral torsion was measured via computed tomography imaging using transcondylar slices of the knee. Anterior capsular thickness was measured using oblique-sagittal sequences on a 3.0-T magnetic resonance imaging system. The association between anterior capsular thickness and related variables, including femoral torsion, was assessed via multiple linear regression. The patients were then divided into 2 groups to further confirm the effect of femoral torsion on capsular thickness: Patients in the study group had hips with moderate (20°-25°) or severe (>25°) antetorsion, whereas patients in the control group had hips with normal torsion (5°-20°) or retrotorsion (<5°). Anterior capsular thickness was also compared between the 2 groups., Results: A total of 156 patients (89 female patients [57.1%] and 67 male patients [42.9%]) were finally included in the study. The mean age and body mass index of the included patients were 35.8 ± 11.2 years and 22.7 ± 3.5, respectively. The mean femoral torsion for the entire study population was 15.9° ± 8.9°. Multivariable regression analysis showed that femoral torsion (P < .001) and sex (P = .002) were significantly correlated with anterior capsular thickness. Propensity-score matching yielded 50 hips in the study group and 50 hips in the control group on femoral torsion subanalysis. The results showed that anterior capsular thickness was significantly smaller in the study group than in the control group (3.8 ± 0.5 mm vs 4.7 ± 0.7 mm, P < .001)., Conclusions: Femoral torsion is significantly inversely correlated with anterior capsular thickness., Level of Evidence: Level III, retrospective comparative study., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To identify the minimal clinically important difference (MCID), substantial clinical benefit (SCB) and patient-acceptable symptomatic state (PASS) for commonly used patient-reported outcomes (PROs) in recurrent patellar instability patients after medial patellofemoral ligament reconstruction (MPFLR) and tibial tubercle transfer (TTT), and to determine the impact of potential prognostic factors on the likelihood of achieving these values., Methods: From April 2015 to February 2021, patients who underwent MPFLR and TTT were retrospectively reviewed. PROs included Kujala, Knee Injury and Osteoarthritis Outcome (KOOS), Lysholm, International Knee Documentation Committee (IKDC), and Tegner score. Relevant anchor questions were provided. A distribution- or anchor-based method was adopted to determine the MCID, SCB, and PASS. Minimal detectable change (MDC) was included to confirm the validity. Univariate regression analyses were conducted to determine the potential prognostic factors., Results: One hundred forty-two patients were included. The MCID were 9.1 (Kujala), 11.1 (Lysholm), 0.9 (Tegner), 9.9 (IKDC), 9.0 (KOOS-Pain), 10.8 (KOOS-Symptoms), 10.0 (KOOS-Activities of Daily Living [ADL]), 17.8 (KOOS-Sports and Recreation [Sports/Rec]), and 12.7 (KOOS-Quality of Life [QoL]). The SCB were 14.5 (Kujala), 12.5 (Lysholm), 1.5 (Tegner), 14.5 (IKDC), 13.9 (KOOS-Pain), 14.3 (KOOS-Symptoms), 18.4 (KOOS-ADL), 47.5 (KOOS-Sports/Rec), and 15.0 (KOOS-QoL). The PASSs were 85.5 (Kujala), 75.5 (Lysholm), 3.5 (Tegner), 73.2 (IKDC), 87.5 (KOOS-Pain), 73.2 (KOOS-Symptoms), 92.0 (KOOS-ADL), 77.5 (KOOS-Sports/Rec), and 53.1 (KOOS-QoL). All SCBs were valid except KOOS-QoL. All MCIDs were valid at the 95% confidence interval (CI) except KOOS scores, the majority of which were valid at the 90% CI. A younger age was an independent prognostic factor of reaching PASS for Lysholm, IKDC, Tegner, and KOOS-ADL score. A higher baseline score was a negative prognostic factor for achieving MCID or SCB but had a slightly positive influence on the achievement of PASS., Conclusions: This study established the MCID, SCB, and PASS for commonly used PROs and confirmed their validity in recurrent patellar instability patients after MPFLR and TTT. Younger age and lower baseline scores were prognostic factors of achieving MCID and SCB, whereas patients with higher baseline scores were more likely to report satisfaction., Level of Evidence: Level III, retrospective comparative prognostic trial., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare clinical and computed tomography outcomes between the arthroscopic Latarjet procedure and the arthroscopic Bristow procedure., Methods: Patients who underwent arthroscopic Latarjet or Bristow procedures with at least 2 years of follow-up were retrospectively reviewed. Thirty-eight shoulders were included in the Latarjet group, and 34 were included in the Bristow group. Recurrence of dislocation, clinical scores, rate of return to sports (RTS), and computed tomography assessment findings (position of transferred coracoid, graft healing, graft absorption, and glenohumeral degenerative osteoarthritis [OA]) were obtained at final follow-up., Results: No recurrent dislocation occurred in either group, and no significant differences in clinical scores were found between the 2 procedures, with a mean follow-up period of 3.4 years. The operative time in the Bristow group was significantly shorter than that in the Latarjet group (P < .001). The transferred coracoid had healed in 94.7% of the patients in the Latarjet group and 85.3% in the Bristow group at final follow-up (P = .01). No significant difference in graft absorption or the degree of glenohumeral OA was detected between the 2 groups. However, moderate to severe OA only occurred in the Latarjet group at final follow-up (4 of 38 shoulders, 10.5%). The postoperative external rotation angle and level of RTS favored the Latarjet procedure (P = .030 and P = .034, respectively)., Conclusions: Both the arthroscopic Latarjet and arthroscopic Bristow procedures led to good clinical scores with no new dislocation episodes. The Bristow group showed significantly less graft healing than the Latarjet group. However, the arthroscopic Bristow procedure took less operative time and showed a lower rate of early moderate to severe glenohumeral OA, better range of motion, and a higher rate of RTS., Level of Evidence: Level III, retrospective comparative therapeutic trial., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the ultrasound imaging manifestations associated with subspine impingement (SSI), including the osseous and soft-tissue injuries adjacent to anterior inferior iliac spine (AIIS) and to investigate the diagnostic value of ultrasound for SSI., Methods: We retrospectively evaluated patients who attended the sports medicine department of our hospital and underwent arthroscopic treatment for femoroacetabular impingement (FAI) between September 2019 and October 2020, with preoperative hip joint ultrasound and computed tomography (CT) examination within 1 month before surgery. All of the FAI patients were divided into the SSI group and non-SSI group, according to the clinical and intraoperative findings. The preoperative ultrasound and CT findings were assessed. The sensitivity, specificity, and positive predictive value (PPV) of some indicators were calculated and compared. Multivariable logistic regression and receiver operating characteristic curve (ROC) were also used., Results: A total of 71 hips were included, with a mean age of 35.4 ± 10.4 years, 56.3% were women. Of these, 40 hips had clinically confirmed SSI. The bone morphology type III, heterogeneous hypoecho in anterosuperior joint capsule and the direct head of rectus femoris (dRF) tendon adjacent to AIIS on the Standard Section of the dRF in ultrasound were associated with SSI. Among them, the heterogeneous hypoecho in the anterosuperior joint capsule had the best diagnostic value for the SSI (85.0% sensitivity, 58.1% specificity, AUC = 0.681). The AUC of the ultrasound composite indicators was 0.750. The AUC and PPV of CT low-lying AIIS for the SSI diagnosis was 0.733 and 71.7%, which could be improved when CT was combined with the ultrasound composite indicators with AUC = 0.831 and PPV = 85.7%., Conclusions: Bone morphology abnormalities and soft-tissue injuries adjacent to the AIIS through sonographic evaluation were associated with SSI. Ultrasound could be used as a feasible method to predict SSI. The diagnostic value for SSI could be improved when ultrasound is combined with CT., Level of Evidence: Level IV, case series., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To study the effects of concomitant subchondral bone cysts (SBCs) on prognosis after arthroscopic bone marrow stimulation (BMS) for osteochondral lesions of the talus (OLTs) less than 100 mm 2 and to further assess the correlation between cystic OLT area, depth, or volume and postoperative outcomes., Methods: We retrospectively analyzed consecutive patients with OLTs (<100 mm 2 ) who received BMS between April 2017 and May 2020 with a minimum follow-up of 24 months. Lesion area, depth, and volume were collected on preoperative magnetic resonance imaging. Visual analog scale (VAS), American Orthopedic Foot and Ankle Society, Karlsson-Peterson, Tegner, Foot and Ankle Ability Measure (FAAM)-Activities of Daily Life and Sports scores were assessed before surgery and at the latest follow-up. Additionally, a general linear model (GLM) and a Pearson correlation analysis (PCA) were performed to investigate the effects of concomitant cysts on postoperative results., Results: Eighty-two patients with a mean follow-up of 39.22 ± 12.53 months were divided into non-cyst (n = 45; 39.91 ± 13.03 months) and cyst (n = 37; 38.37 ± 12.02 months) groups. There was no significant difference in the OLT area between the non-cyst and cyst groups (46.98 ± 19.95 mm 2 vs 56.08 ± 22.92 mm 2 ; P = .093), but the cyst group showed significantly greater depth (6.06 ± 1.99 mm vs 3.96 ± 1.44 mm; P = .000) and volume (248.26 ± 156.81 mm 3 vs 134.58 ± 89.68 mm 3 ; P = .002). The non-cyst group showed significantly more improvement in VAS pain, Karlsson-Peterson, Tegner, and FAAM scores than the cyst group (P < .05). The GLM indicated that SBCs negatively affected VAS pain and Tegner scores (P < .05). For OLTs with cysts, the PCA showed that an area of 90.91 mm 2 , depth of 7.56 mm, and volume of 428.13 mm 3 were potential cutoff values associated with poor outcomes., Conclusions: The concomitant SBCs negatively affected the prognosis of OLTs after BMS. For OLTs with cysts, an area of 90.91 mm 2 , depth of 7.56 mm, and volume of 428.13 mm 3 were the potential cutoff values associated with poor outcomes after BMS., Level of Evidence: Level III, retrospective comparative study., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the functional outcomes, range of motion (ROM), recurrence rates, and complication rates of arthroscopic autologous iliac crest grafting (AICG) and Remplissage plus Bankart repair (RB) for anterior shoulder instability with bipolar bone defects., Methods: This study enrolled patients undergoing arthroscopic AICG or RB with 13.5-25% glenoid bone defect combined with Hill-Sachs lesion between January 2013 and April 2020, who had a minimum 2-year follow-up. Patient-reported outcomes were evaluated by Subjective Shoulder Value (SSV), Oxford Shoulder Instability Score (OSIS), Rowe score, Constant score, and visual analog scale (VAS) for pain. Active ROM, return to sports, recurrence, self-reported apprehension, and complications were recorded., Results: This study included 60 patients, including 28 AICG (Group A) and 32 RB (Group R). Mean glenoid bone defect was similar (17.7% ± 3.1% vs 16.6% ± 2.4%; P = .122). Both groups showed significant postoperative improvement in Rowe score, SSV, OSIS, and Constant score. No significant difference was found in postoperative Rowe Score (87.7 vs 85.2; P = .198). A total of 20/28 (71.4%) patients in Group A versus 26/32 (81.3%) patients in Group R met the Patient Acceptable Symptomatic State determined by VAS pain score (P = .370). Both groups showed high return-to-sports rates (67.8% vs 71.8%; P = .735) and slightly decreased ROM. There were two cases of recurrence in Group A versus one in Group R (P = .594). Group R had insignificantly higher positive self-reported apprehension rate (40.6% vs 17.9%; P = .055)., Conclusions: For anterior shoulder instability with bipolar bone defects, both arthroscopic AICG and RB can result in satisfactory clinical outcomes, good postoperative ROM, and low recurrence and complication rates., Level of Evidence: Level III, retrospective cohort study., (Copyright © 2023. Published by Elsevier Inc.)

Purpose: To compare the clinical outcomes of arthroscopic dynamic anterior stabilization (DAS) between transferring the long head of the biceps (DAS-LHB) and the conjoined tendon (DAS-CT) for anterior shoulder instability with <15% glenoid bone loss., Methods: From January 2016 to May 2019, a total of 63 patients who underwent DAS for recurrent anterior shoulder dislocation with <15% glenoid bone loss were included, comprising 33 patients in DAS-LHB group and 30 patients in DAS-CT group. Clinical outcomes were assessed preoperatively and at a minimum 3-year follow-up, including patient-reported outcomes, range of motion, and return to sports (RTS). Postoperative recurrent instability (including dislocation, subluxation, and subjective instability with a positive apprehension test), revisions and complications also were recorded., Results: No significant demographic characteristics difference was detected between the DAS-LHB (26.3 ± 7.9 years) and DAS-CT groups (26.0 ± 6.7 years). At the latest follow-up, there were no significant differences between the 2 groups in functional scores: Oxford Shoulder Instability Score (14.8 ± 2.8 vs 15.2 ± 3.6), Rowe score (95.9 ± 6.5 vs 93.2 ± 10.2), visual analog scale for pain (0.8 ± 1.2 vs 0.7 ± 1.7), and American Shoulder and Elbow Surgeons (95 ± 8.8 vs 95.2 ± 9.1) (all P > .218). No significant difference was detected between groups in the rates of RTS (90.1% vs 86.7%, P = .700) and RTS at previous level (78.7% vs 73.3%, P = .258), respectively. No recurrent dislocation occurred in either group. One patient felt occasional subluxation in the DAS-LHB group, and one was positive for the apprehension test in each group. One patient presented with postoperative shoulder stiffness and underwent a secondary arthroscopic debridement in the DAS-CT group., Conclusions: Comparable rates of recurrence, complication, return to sports, and subjective shoulder function were observed between DAS-LHB and DAS-CT groups., Level of Evidence: Level III, retrospective comparative therapeutic trial., (Copyright © 2023. Published by Elsevier Inc.)

Purpose: To evaluate the changes in anterior hip capsular thickness on pre- and postoperative magnetic resonance imaging (MRI) and their associated clinical outcomes in patients with borderline developmental dysplasia of the hip (BDDH)., Methods: A minimum 2-year follow-up retrospective analysis was performed using data from symptomatic patients with BDDH who underwent hip arthroscopy with routine capsular closure between 2018 and 2020. An available postoperative hip MRI was a prerequisite for study inclusion. Capsular thickness at the capsulotomy zone was measured on MRI. An analysis of the correlations between anterior capsular thickness differences and demographic factors (including age, sex, body mass index, laterality, preoperative alpha angle and lateral center-edge angle, cartilage lesion grade, follow-up time, and capsule management) was performed. Patients with unhealed or partially healed capsules (study group) were propensity-score matched 1:1 to patients with completely healed capsules based on age, sex, body mass index, and follow-up time. Comparisons and analyses of the following parameters were completed for both groups: patient-reported outcomes (Hip Outcome Score-Activities of Daily Living [HOS-ADL], Hip Outcome Score-Sports-Specific Subscale [HOS-SSS], International Hip Outcome Tool 12-component form [iHOT-12], and modified Harris Hip Score), visual analog scale scores, radiographic measures, performed procedures, and complications., Results: Data were compiled for 59 patients' hips after patient selection. The majority of the repaired hip capsules remained closed (93.2%) at a minimum 2-year follow-up. Propensity-score matching was applied to distribute 25 subjects in the study group and 25 in the control group. The anterior capsule was significantly thinner postoperation in the study group (3.0 ± 1.2 mm vs 4.1 ± 0.6 mm; P < .001). Compared with the control group, patients in the study group had significantly inferior postoperative HOS-ADL (75.1 vs 83.5, P = .007), HOS-SSS (64.5 vs 77.1, P = .005), and iHOT-12 scores (56.1 vs 70.2, P = .006). In addition, patients in the study group were significantly less likely to achieve the minimum clinically important difference for the HOS-ADL score (52% vs 80%, P = .037) score and patient acceptable symptomatic state for the HOS-ADL score (32% vs 60%, P = .047)., Conclusions: The majority of the repaired hip capsules in patients with BDDH remained closed but not all capsules completely healed at a minimum 2-year follow-up. Patients with an unhealed or partially healed capsule had inferior HOS-ADL, HOS-SSS, and iHOT-12 scores and were less likely to achieve the minimum clinically important difference and patient acceptable symptomatic state for the HOS-ADL score., Level of Evidence: III, retrospective comparative prognostic study., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: The purposes of our study were 1) to investigate the potential change of labral size after arthroscopic repair and 2) to analyze the relationship between acetabular labral size and functional outcomes., Methods: In this retrospective study, patients diagnosed with labral tear and undergoing hip arthroscopic repair in our institution between September 2016 and December 2018 were included. Magnetic resonance imaging was obtained preoperatively and postoperatively, and the labral length and labral height were measured in three anatomic sites: 11:30, 1:30, and 3:00 positions. All patients completed at least 2-year follow-up. Patients whose preoperative labral size in any position wider than 2 standard deviation away from the mean were identified as the hypertrophic labrum group and were compared with the control in radiographic variables and patient-reported outcomes (PROs), including the visual analog scale (VAS), modified Harris Hip Score (mHHS), the International Hip Outcome Tool-12 (iHOT-12) and the Hip Outcome Score-Activities of Daily Living (HOS-ADL)., Results: A total of 82 patients (82 hips) were included, and the mean follow-up period was 39.54 ± 8.48 months. Significant improvement in PROs was determined before and after surgeries. Twelve patients were identified with labral hypertrophy and had higher postoperative mHHS scores, higher postoperative iHOT-12 scores, and greater improvement in HOS-ADL compared with the control group. Patients with larger preoperative anterosuperior labral height exhibited more favorable clinical outcomes. Meanwhile, no significantly morphologic change in labral size was determined., Conclusion: There is no significantly morphologic change in labral size of superior, anterosuperior, and anterior labrum after arthroscopic repair. Patients with hypertrophic labrum achieved more favorable clinical outcomes compared with those with normal-sized labrum., Level of Evidence: Level III, retrospective comparative prognostic trial., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To define the clinical effect of intra-articular injection of iliac crest-derived bone marrow aspirate concentrate (BMAC) at the time of hip arthroscopy in patients with symptomatic labral tears and early radiographic degenerative changes., Methods: A retrospective review of a prospectively collected hip registry database was performed. Patients with symptomatic labral tears and Tönnis grade 1 or 2 degenerative changes who underwent labrum-preserving hip arthroscopy with BMAC injection were included and were matched with patients who underwent hip arthroscopy without BMAC injection. Patient-reported outcomes (PROs) collected preoperatively and up to 2 years postoperatively included the modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, Hip Outcome Score-Sport, and International Hip Outcome Tool 33 score. Clinical relevance was measured with the minimal clinically important difference, patient acceptable symptom state, and substantial clinical benefit for each outcome score., Results: A total of 35 patients underwent labrum-preserving hip arthroscopy with BMAC injection and were matched with 35 control patients. There were no differences in demographic characteristics between the groups (P > .05). The BMAC group consisted of 22 patients (62.9%) with Tönnis grade 1 changes and 13 (37.1%) with Tönnis grade 2 changes, whereas all 35 control patients had Tönnis grade 0 hips. All PROs were significantly improved in both groups at 2 years, with no difference in improvement. The rate of failure requiring conversion to total hip arthroplasty was 14.3% (mean, 1.6 years postoperatively) in the BMAC group and 5.7% (mean, 7 years postoperatively) in the control group (P = .09). The difference in the frequency of patients achieving the minimal clinically important difference, patient acceptable symptom state, and substantial clinical benefit was not statistically significant between cohorts., Conclusions: In a challenging group of patients with symptomatic labral tears and early radiographic degenerative changes, hip arthroscopy with BMAC injection results in statistically and clinically significant improvement in PROs comparable to a group of patients with nonarthritic hips undergoing hip arthroscopy at short-term follow-up., Level of Evidence: Level III, retrospective comparative therapeutic trial., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the return to sports and short-term clinical outcomes between the arthroscopic all-inside and the open anatomic reconstruction with gracilis tendon autograft for chronic lateral ankle instability (CLAI) patients., Methods: From March 2018 to January 2020, 57 CLAI patients were prospectively included with arthroscopic all-inside anatomic reconstruction (n = 31) or open anatomic reconstruction (n = 26) with gracilis tendon autograft. The patients were evaluated before operation and at 3 months, 6 months, 12 months, and 24 months after surgery. The American Orthopaedic Foot and Ankle Society score (AOFAS), visual analog scale (VAS), and Karlsson-Peterson score were evaluated at each time point, and stress radiography with a Telos device was performed before surgery and at final follow-up. The time to return to full weightbearing walking, jogging, sports, and work, Tegner activity score, and complications were recorded and compared., Results: All the subjective scores significantly improved after surgery from the preoperative level. Compared with the open group, the arthroscopic group demonstrated significantly earlier return to full weightbearing walking (8.9 vs 11.7 weeks, P < .001), jogging (17.9 vs 20.9 weeks, P = .012), and recreational sports (22.4 vs 26.5 weeks, P = .001) with significantly better AOFAS score and Karlsson score at 3 to 6 months, and better VAS score at 6 months after surgery. The 2 groups demonstrated no significant difference in the surgical duration or surgical complications. No significant difference was found in the clinical scores or stress radiographic measurements at 24 months after surgery (P > .05)., Conclusion: Compared with the open procedure, the arthroscopic all-inside anatomic lateral ankle ligament reconstruction with autologous gracilis tendon could achieve earlier return to full weightbearing, jogging, and recreational sports with less pain and better ankle functional scores at 3 to 6 months after surgery. Similar favorable short-term clinical outcomes were achieved for both techniques at 2 years after surgery., Study Design: Level I, randomized controlled trial., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To introduce a simple patellar height measurement method (patella-posterior turning point of the distal femur [P-PTP] Distance) independent of patellar anatomy with standardized patient position, and tested the reliability, validity, and diagnostic accuracy compared with commonly used ratios in knee extension., Methods: We retrospectively reviewed 418 computed tomography (CT) images of the knee joint in a group of patients who were diagnosed recurrent patellar dislocation (RPD). With the three-dimensional (3D) CT reconstructed knee, patellar height was qualitatively assessed by the patellar engagement with the femoral trochlea in terminal knee extension to divide RPD population into case (patella alta) and control group. With digitally reconstructed lateral radiographs, patellar height was measured with P-PTP distance (perpendicular distances between the distal edge of patella articular surface and posterior turning point of distal femur), and four commonly used ratios: Caton-Deschamps index, Modified Insall-Salvati index, Blackburne-Peel index, and Insall-Salvati index. An unpaired t-test was conducted to determine significant differences between groups. Correlation coefficient, intra- and inter-observer reliability, receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were also calculated., Results: 198 knee images (198 patients) were included for final evaluation. Patella alta was present in 72 knees (36.3%) with RPD. The effect size was relatively large between the case and control group for P-PTP distance (d = -1.619; 95% CI, -1.948 to -1.286). P-PTP distance correlated moderately to strongly with four commonly used ratios (P < .001). Intraobserver and interobserver reliability was good for P-PTP distance. The AUC of the ROC curve was categorized as excellent for P-PTP distance, better than other measurements (P < .001), and the cutoff value was 4.2 mm with the highest sensitivity (86.11%) and specificity (84.92%)., Conclusions: The measurement method, P-PTP distance, showed good intra-observer and inter-observer reliability, well correlated with commonly used ratios, and presented best diagnostic accuracy among commonly used ratios for predicting RPD. P-PTP distance might be a potential indicator for identifying patella alta in RPD patients when supine and knee extended., Clinical Relevance: The measurement reported in this study may help in advancing clinical evaluation of patella alta, providing an alternative and simple method to measure patellar height. Standing or weight-bearing plain lateral radiographs obtained from the routine practice should be further assessed in the next step to further validate the method., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the clinical outcomes of hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and their predictors at a minimum 5 years' follow-up., Methods: We retrospectively analyzed patients with FAIS after first-time unilateral hip arthroscopy between January 2010 and July 2016. Patient-reported outcomes (PROs) included the validated modified Harries Hip Score (mHHS) and Visual Analog Scale for Pain (Pain VAS). We included patients with Tönnis grade 0 or 1 and reported PROs, and excluded patients with previous hip diseases or bilateral symptoms. Bivariate and multivariate analyses were used for data analysis., Results: We included 159 patients with a mean follow-up of 6.4 years, aged 36.18 ± 8.61 years, 41.5% female, and a mean body mass index of 23.61 ± 3.45. The mean postoperative mHHS was 88.82 ± 11.60, and the mean Pain VAS was 1.93 ± 1.89, significantly better than before surgery (P < .001). Postoperative alpha angle (P = .003) and lateral center edge angle (P < .001) were significantly decreased. Most patients (83.7%) achieved clinically important improvement based on patient-acceptable symptom state and minimal clinically important difference (MCID). The overall revision surgery rate was 2.5%. There were no conversions to total hip arthroplasty. Bivariate analysis indicated that age (P < .001), preoperative mHHS (P = .002), and postoperative Pain VAS (P <.001) correlated with postoperative mHHS at a minimum 5 years' follow-up. Multivariate regression analysis of MCID showed that age (P <.001), preoperative PROs (P < .01 for both), and postoperative Pain VAS (P < .001) were significant outcome predictors., Conclusion: Patients with FAIS after first-time unilateral hip arthroscopy showed significant improvement in PROs at mid-term follow-up, with a low revision surgery rate. Young patients and those with low postoperative Pain VAS showed excellent outcomes at a minimum 5 years' follow-up., Level of Evidence: Level IV, retrospective case series., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the clinical outcomes of arthroscopically assisted double-bundle medial patellofemoral complex reconstruction (MPFC-R)., Methods: A retrospective review was carried out among adult patients who experienced at least 2 patellar dislocations and underwent primary arthroscopically assisted MPFC-R between January 2014 and November 2019. Dejour classification, tibial tubercle-trochlear groove (TT-TG) distance, and patellar height (with Insall-Salvati index) were measured. Pre- and postoperative patellar tilt were compared. Information on outcome scores, ability to return to sports, postoperative recurrent dislocations, and complications was recorded., Results: A total of 42 MPFC-Rs in 39 patients were included. Mean age at surgery was 22.2 ± 7.6 years; 69.2% of patients were female. Mean follow-up was 47.3 ± 20.2 months. Seventy-four percent of cases had Dejour B (19.0%), C (33.3%), and D (21.4%) trochlear dysplasia; mean TT-TG distance was 19.6 ± 3.5 mm, and mean Insall-Salvati index was 1.21 ± 0.17. Mean patellar tilt decreased from 27.6 ± 11.6° to 9.4 ± 6.5° (P < .001). All patients had statistically significant (P < .001) improvement in mean International Knee Documentation Committee (IKDC) (44.9 ± 18.2 to 87.5 ± 6.9), Lysholm (61.4 ± 16.6 to 94.1 ± 6.4), Kujala (56.0 ± 16.8 to 92.9 ± 5.3), and Tegner score (2.7 ± 1.3 to 4.6 ± 1.4). The majority of patients (96.9%) returned to sports, with 90.3% returning to the same or greater level of activity. No postoperative dislocations or subluxations were reported., Conclusions: Arthroscopically assisted double-bundle MPFC-R is a promising procedure to treat recurrent patellar instability at 2- to 7-year mid-term follow-up, despite the presence of trochlear dysplasia, elevated TT-TG distance and patellar alta. The improvement of IKDC score exceeded the minimal clinically important difference in 95.2% patients, and 66.7% surpassed the patient acceptable symptomatic state based on postoperative IKDC score with no redislocations being reported at latest follow-up., Level of Evidence: Level IV, case series, retrospective., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the biomechanical effects of femoral cortical surface fixation and intra-tunnel fixation in modified Lemaire tenodesis on the restoration of native kinematics in anterolateral structure-deficient knees., Methods: Eight fresh-frozen cadaveric knees were mounted in a knee-customized jig to evaluate anterior translation in anterior load and internal rotation degree in internal rotation torque at 0°, 30°, 60°, and 90°, as well as anterolateral translation (ALT) in a simulated pivot-shift test at 0°, 15°, 30°, and 45°. Kinematic tests were performed in the following states: intact; anterolateral knee lesion (AL-Les); modified Lemaire lateral extra-articular tenodesis (LET) with the femoral iliotibial band (ITB) strip fixed on the cortical surface (cortical fixation), deep to the lateral collateral ligament (LCL) (deep LET-C); and LET with the femoral ITB strip fixed into a tunnel (intra-tunnel fixation), deep to the LCL (deep LET-IT) or superficial to the LCL (superficial LET-IT). The knee kinematic changes in the AL-Les state and the 3 LET states were compared with each other, with the intact state as the baseline., Results: In the AL-Les state, the increased anterior translation instabilities were significantly mitigated by the 3 LETs at 30°, 60°, and 90° (all P < .001), with overconstraint observed in both the deep LET-IT and superficial LET-IT states at 60° (P = .047 and P < .001, respectively) and 90° (both P < .001). Similarly, the 3 LETs significantly reduced the internal rotation instabilities in the AL-Les state at all flexion angles. The superficial LET-IT state overconstrained the knee at 60° (P = .009) and 90° (P < .001) during internal rotation torque, and the deep LET-IT state did so at 60° (P = .012). Furthermore, the ALT instabilities found in the AL-Les state were significantly reduced by the 3 LETs during the simulated pivot-shift test. At 30° and 45°, these LET states resulted in overconstraint when compared with the intact state, but the superficial LET-IT state (P < .001) or deep LET-IT state (P = .016) presented a larger overconstraint than that in the deep LET-C at 45°, respectively., Conclusions: The 3 Lemaire LET procedures evaluated reduced the anterior, internal rotational, and ALT laxities in AL-Les knees and restored these parameters to the native baseline of the intact state at most flexion angles. However, in deep flexion, some overconstraint occurred in all LETs when compared with the intact state, of which the deep LET-C state resulted in less overconstraint in anterior translation and internal rotation than the deep LET-IT and superficial LET-IT states., Clinical Relevance: This biomechanical study supports using the femoral cortical fixation technique to fix the ITB strip in the modified Lemaire LET, which similarly improves knee kinematic stability and causes less overconstraint compared with conventional intra-tunnel fixation. These findings need more verification in clinical scenarios., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the reliability, construct validity, and responsiveness of the lower extremity-specific Patient-Reported Outcomes Measurement Information System (PROMIS) Mobility (MO) bank in patients who underwent hip arthroscopic surgery for femoroacetabular impingement., Methods: Patients who underwent primary hip arthroscopic surgery at a large academic musculoskeletal specialty center between November 2019 and November 2020 completed the following baseline and 6-month measures: PROMIS MO, PROMIS Pain Interference (PI), PROMIS Physical Function (PF), modified Harris Hip Score, International Hip Outcome Tool 33, visual analog scale, and Single Assessment Numeric Evaluation. Construct validity was evaluated using Spearman correlation coefficients. The number of questions until completion was recorded as a marker of test burden. The percentage of patients scoring at the extreme high (ceiling) or low (floor) for each measure was recorded to measure inclusivity. Responsiveness was tested by comparing differences between baseline and 6-month measures, controlling for age and sex, using generalized estimating equations. Magnitudes of responsiveness were assessed through the effect size (Cohen d)., Results: In this study, 660 patients (50% female patients) aged 32 ± 14 years were evaluated. PROMIS MO showed a strong correlation with PROMIS PF (r = 0.84, P < .001), the International Hip Outcome Tool 33 (r = 0.73, P < .001), PROMIS PI (r = -0.76, P < .001), and the modified Harris Hip Score (r = 0.73, P < .001). Neither PROMIS MO, PROMIS PI, nor PROMIS PF met the conventional criteria for floor or ceiling effects (≥15%). The mean number of questions answered (± standard deviation) was 4.7 ± 2.1 for PROMIS MO, 4.1 ± 0.6 for PROMIS PI, and 4.1 ± 0.6 for PROMIS PF. From baseline to 6 months, the PROMIS and legacy measures exhibited significant responsiveness (P < .05), with similar effect sizes between the patient-reported outcome measures., Conclusions: This longitudinal study reveals that in patients undergoing hip arthroscopy, PROMIS MO computerized adaptive testing maintains high correlation with legacy hip-specific instruments, significant responsiveness to change, and low test burden compared with legacy measures, with no ceiling or floor effects at 6-month postoperative follow-up., Level of Evidence: Level IV, retrospective case series., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: This study aimed to compare the clinical, functional, and imaging outcomes of single-tunnel (ST) and double-tunnel (DT) techniques for medial patellofemoral ligament (MPFL) reconstruction., Methods: Ninety-four patients with recurrent patellar instability were randomly divided into 2 groups, receiving either ST or DT MPFL reconstruction. Lateral reticulum release (LRR) and tibial tuberosity (TT) transfer were performed as combined procedures when necessary. Preoperative and postoperative clinical characteristics (symptoms and episodes of redislocation), functional outcomes (Kujala, Lysholm, Tegner, IKDC, and KOOS score), and radiological measurements (congruence angle, patellar tilt angle, lateral patellar angle, and lateral patellar translation) were analyzed., Results: The analysis included data from 90 patients with 48 patients in the ST group and 42 patients in the DT group. Patients were followed up for a mean period of 37.8 (range: 27-50) months in the ST group and 38.6 (range: 25-53) months in the DT group. Forty-three patients in the ST group and 40 patients in the DT group received combined TT transfer, and all patients underwent LRR. At the latest follow-up, 1 patient in ST group experienced redislocation, while no patient in the DT group sustained clinical failure (P = .347). Imaging measurements decreased significantly to the normal range postoperatively. No significant difference was noted between the postoperative radiological results of the 2 groups. All clinical scores significantly improved postoperatively, and no significant difference was observed between the 2 groups except for the higher Lysholm score (P = .031), KOOS symptoms score (P = .021) and KOOS knee-related quality of life score (P = .043) in the DT group., Conclusion: Both techniques could equally mitigate the patellar lateral translation or redislocation. Our results demonstrate several significant differences in functional outcomes that favored DT MPFL reconstruction but no difference in clinical failure rates and radiological results between ST and DT MPFL reconstruction., Level of Evidence: Level I, randomized clinical trial., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess the clinical utility of preoperative magnetic resonance imaging (MRI) and quantify the delay in surgical care for patients aged ≤40 years undergoing primary hip arthroscopy with history, physical examination, and radiographs concordant with femoroacetabular impingement syndrome (FAIS)., Methods: From August 2015 to December 2020, 1,786 consecutive patients were reviewed from the practice of 1 fellowship-trained hip arthroscopist. Inclusion criteria were FAIS, primary surgery, and age ≤40 years. Exclusion criteria were MRI contraindication, reattempt of conservative management, or concomitant periacetabular osteotomy. After nonoperative treatment options were exhausted and a surgical plan was established, patients were stratified by those who presented with versus without MRI. Those without existing MRI received one, and any deviations from the surgical plan were noted. All preoperative MRIs were compared with office evaluation and intraoperative findings to assess agreement. Demographic data, Hip Disability and Osteoarthritis Outcome Score (HOOS)-Pain, and time from office to MRI or arthroscopy were recorded., Results: Of the patients indicated by history, physical examination, and radiographs alone (70% female, body mass index 24.8 kg/m 2 , age 25.9 years), 198 patients presented without MRI and 934 with MRI. None of the 198 had surgical plans altered after MRI. Patients in both groups had MRI findings demonstrating anterosuperior labral tears that were visualized and repaired intraoperatively. Mean time from office to arthroscopy for patients without MRI versus those with was 107.0 ± 67 and 85.0 ± 53 days, respectively (P < .001). Time to MRI was 22.8 days. No difference between groups was observed among the 85% of patients who surpassed the HOOS-Pain minimal clinically important difference (MCID)., Conclusion: Once indicated for surgery based on history, physical examination, and radiographs, preoperative MRI did not alter the surgical plan for patients aged ≤40 years with FAIS undergoing primary hip arthroscopy. Moreover, preoperative MRI delayed time to arthroscopy. The necessity of routine preoperative MRI in the young primary FAIS population should be challenged., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate the effects of the number and location of anchors for remplissage on postoperative glenohumeral biomechanics., Methods: A biomechanical study was conducted involving finite element model constructed based on data from the intact glenohumeral joint. Seven models were established, including a normal model, a model of Bankart lesion combined with "off-track" Hill-Sachs lesion, a model of Bankart repair alone, and 4 models of Bankart repair with remplissage based on different remplissage anchor numbers and locations. The effects of the number and location of the remplissage anchors on glenohumeral stability were studied through calculation and comparison of (1) the stress and its distribution on the joint capsule, cartilage, labrum and anchors as well as (2) the displacement of the humeral head., Results: Finite element analysis demonstrated that contact stress on the glenohumeral cartilage decreased when medial or 2 anchors were used and was minimized in the combined repair model with 2 medial anchors. The stress on remplissage anchors was greater when the anchors were placed medially. The humeral head displacement was maximized in the combined lesion model. The combined repair models with 2 medially placed anchors showed the largest slope on the force-displacement curve, indicating the largest strain on the humeral head., Conclusions: Based on a finite element analysis, Bankart repair with remplissage restored better shoulder stability compared with Bankart repair alone in the treatment of anterior shoulder instability involving Bankart lesion combined with "off-track" Hill-Sachs lesion. When the anchor for remplissage was medially placed or 2 anchors were used, the stability of the glenohumeral joint increased but with a loss of range of motion., Clinical Relevance: The results of this study will assist in choosing the number and location of anchors for remplissage during shoulder stabilization surgery although with some limitations., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare the biomechanical effects of anterolateral structure reconstructions (ALSRs) with different tibial attachments on tibiofemoral kinematics and anterolateral structure (ALS) graft forces., Methods: Eight cadaveric knees were tested in a customized knee testing system, using a novel pulley system to simulate more muscle tensions by loading the iliotibial band at 30 N and quadriceps at 10 N in all testing states. Anterior stability during anterior load and anterolateral rotatory stability during 2 simulated pivot-shift tests (PST1 and PST2) were evaluated in 5 states: intact, ALS-deficient (Def), ALSR-Ta (anterior tibial site), ALSR-Tm (middle tibial site), and ALSR-Tp (posterior tibial site). Tibiofemoral kinematics and resulting ALS graft forces against the applied loads were measured and compared in the corresponding states., Results: In anterior load, 3 ALSRs mitigated the anterior laxities of the ALS Def state at all degrees, which were close to intact state at 0° and 30° but showed significantly overconstraints at 60° and 90°. In both PSTs, all ALSRs significantly reduced the anterolateral rotatory instability of ALS Def, whereas the significant overconstraints were detected in ALSR-Ta and ALSR-Tm at greater knee flexion angles. All ALS grafts carried forces in resisting anterior and pivot-shift loads. Only ALS graft force in ALSR-Ta increased continuously with knee flexion angles. The ALS graft forces carried by ALSR-Ta were significantly larger than those by ALSR-Tp and ALSR-Tm when resisting anterior load and PSTs at greater knee flexion angles., Conclusions: ALSRs with different tibial attachment sites similarly restored knee laxities close to the native tibiofemoral kinematics in an ALS-deficient knee, whereas the ALSR-Tp showed less propensity for overconstraining the knee at greater flexion angles. The ALS graft in ALSR-Ta carried more forces than those in ALSR-Tp and ALSR-Tm against simulated loads., Clinical Relevance: Altering the tibial attachment sites of ALSRs may not significantly affect tibiofemoral kinematics at most degrees whereas the posterior may have less overconstraints at greater flexion angles. However, ALS graft positioning at a more anterior tibial attachment site may carry more forces in resisting anterior and pivot-shift loads., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To examine the biomechanical differences between labral repair with transferred conjoined tendon and transferred long head of the biceps tendon (LHBT) for anterior shoulder instability with 20% bone loss., Methods: Twelve cadaveric shoulders were tested in sequent 5 conditions: intact, 20% glenoid defect, Bankart repair, Bankart repair with transferred conjoined tendon (dynamic conjoined tendon sling, DCS), and with transferred LHBT (dynamic LHBT sling, DLS) at 60° of glenohumeral abduction and 60° of external rotation. The physiological glenohumeral joint load was created by forces applied to the rotator cuff, conjoined tendon, and LHBT. The glenohumeral compression force and range of motion were recorded before anteroinferior force application. The anterior, inferior, and total translations were measured with 20, 30, 40, and 50 N of anteroinferior force, respectively., Results: Anteroinferior glenoid defect led to significant increase of humerus translation and decrease of glenohumeral compression force. DLS provided better resistance effect in both anterior-posterior and superior-inferior directions than DCS under high loading condition (40 N, P =.03; 50 N, P <.01). Both DCS and DLS procedures could further restore glenohumeral compression force with Bankart repair (Bankart repair: 32.1 ± 4.0 N; DCS: 36.7 ± 3.2 N, P < .01; DLS: 35.8 ± 3.6 N, P =.03). No range of motion restrictions were observed relative to the normal shoulder., Conclusions: Both the DLS and DCS techniques could reduce the anterior-inferior translation and partially restore the glenohumeral stability in anterior shoulder instability with 20% anteroinferior glenoid defect compared with Bankart repair. Under greater loading conditions, DLS provides better stability than DCS., Clinical Relevance: Shoulder stability can be restored by DLS and DCS with low load. With greater shoulder stability requirements, DLS might be a better option than DCS for anterior shoulder instability with 20% bone loss., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To compare short-term follow-up outcomes after primary arthroscopy in femoroacetabular impingement syndrome (FAIS) patients with untreated central acetabular osteophytes (CAO) to a control group without CAO., Methods: A retrospective analysis was performed using data from FAIS patients who had primary arthroscopy between 2017 and 2018. The presence of CAO was confirmed arthroscopically, and there were 2 groups created. The CAO group was 1:1 propensity-score matched to a control group (without CAO) based on age, gender, body mass index (BMI), Tӧnnis grade, symptom duration before surgery, and follow-up time. Patient-reported outcomes (PROs), such as the Hip Outcome Score-Activities of Daily Living (HOS-ADL), International Hip Outcome Tool 12-component form (iHOT-12)，modified Harris Hip Score (mHHS), and visual analog scale (VAS) scores were used to evaluate the level of function included. The minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) were also calculated to determine meaningful outcome improvement. Radiographic measures, performed procedures, complications, and revision surgery were also compared and analyzed for both groups. P values less than .05 were considered statistically significant., Results: A total of 46 hips with CAO and 46 hips without CAO were propensity matched. At the minimum final follow-up of 2 years, the CAO group had significantly lower HOS-ADL (78.8 vs 85.5; P = .008), iHOT-12 (74.8 vs 79.3; P = .019), and mHHS (78.9 vs 87.2; P = .002) scores, as compared to the CAO group. Furthermore, patients in the CAO group were significantly less likely to achieve the MCID and PASS for the mHHS score (78.3% vs 93.5%; P = .036, 58.7% vs 78.2%; P = .043, respectively). There was no change in the rate of complications (4.3% vs 0%) and revision hip arthroscopy (4.3% vs 2.2%) between the two groups at the final follow-up., Conclusions: This study demonstrated that surgically treated FAIS patients with CAO might experience worse short-term, patient-reported outcomes, as compared with propensity-matched patients without CAO., Level of Evidence: III, case-control study., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess the effect of bone marrow aspiration concentrate (BMAC) augmentation on clinical outcomes and magnetic resonance imaging (MRI) findings in anterior cruciate ligament (ACL) reconstruction (ACLR) with bone-patellar tendon-bone (BTB) allografts., Methods: A double-blinded, randomized controlled trial was conducted on 80 patients undergoing ACL reconstruction using BTB allografts. Patients were randomized to 2 groups: (1) bone marrow aspirate was collected from the iliac crest, concentrated, and approximately 2.5 mL was injected into the BTB allograft, or (2) a small sham incision was made at the iliac crest (control). MRI was performed at 3 months and 9 months postoperatively to determine the signal intensity ratio of the ACL graft., Results: Seventy-three patients were available for follow-up at 1-year postoperatively (36 BMAC, 37 control). International Knee Documentation Committee (IKDC) scores were significantly greater in the BMAC group versus the control at the 9-month postoperative period (81.6 ± 10.5 vs 74.6 ± 14.2, P = .048). There was no significant difference in the proportion of patients who met the minimal clinically important difference for IKDC between the BMAC and control groups at 9 months (89% vs 85%; P = .7). Three months postoperatively, signal intensity ratio of the inferior third of the ACL graft was significantly greater in the BMAC group versus the control group (3.2 ± 2.2 vs 2.1 ± 1.5; P = .02)., Conclusions: Patients who received BMAC augmentation of the BTB allograft during ACL reconstruction demonstrated greater signal intensity scores on MRI at 3 months, suggesting increased metabolic activity and remodeling, and potentially accelerated ligamentization. Additionally, patients in the BMAC group had greater patient-reported outcomes (IKDC) at 9 months postoperatively when compared with those who underwent a standard surgical procedure. There was no significant difference in the proportion of patients who met the minimal clinically important difference for IKDC between the BMAC and control groups at 9 months, suggesting limited clinical significance at this time point., Level of Evidence: I, randomized control trial., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate the clinical outcomes and radiologic evaluation of an all-arthroscopic Latarjet procedure with modified button fixation., Methods: Patients who received all-arthroscopic Latarjet procedure with modified suture button fixation between September 2015 to September 2016 were retrospectively reviewed. Indications for surgery were recurrent anterior shoulder dislocation with any 1 of these 3 conditions: glenoid defect >15%, contact-sport athlete, or failure after Bankart repair. Inclusion criteria included cases who received this surgery. Clinical outcomes were evaluated by University of California Los Angeles, ASES and Rowe score with a minimal follow-up of 3 years. Radiologic assessment on 3D computed tomography scan was performed preoperatively and postoperatively at different time points. Complications were also recorded., Results: A total of 30 patients were eventually included in this study. The mean follow-up time was 38.0 ± 2.5 months. There were 25 patients who performed contact sports. Of them, 10 patients were without glenoid defect >15% or failed Bankart repair. The remaining 20 patients had glenoid defect >15%, including 2 failed Bankart cases. Ten patients had glenoid defect < 13.5%, and the rest 20 patients had > 13.5%. UCLA, American Shoulder and Elbow Surgeons, and Rowe score significantly improved during follow-up, and the improvement exceeded MCID for all patients. No severe complications were noted. In total, 86.7% of the graft positioning was measured as flush and 13.3% as medial. The bone union rate was 96.7% at 3 months postoperatively and at final follow-up. The remodeling process for the restoration of the normal anatomy of the lower part of glenoid was noted., Conclusions: All-arthroscopic Latarjet with modified suture button fixation can achieve stable fixation of the coracoid, good clinical outcomes (all patients with improvement exceeding MCID), low complications rate. Furthermore, the bone remodeling process contributes to the recovery of the normal anatomy of anteroinferior glenoid., Study Design: Case series; Level of evidence, 4., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine what subspecialties have applied machine learning (ML) to predict clinically significant outcomes (CSOs) within orthopaedic surgery and to determine whether the performance of these models was acceptable through assessing discrimination and other ML metrics where reported., Methods: The PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases were queried for articles that used ML to predict achievement of the minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), or substantial clinical benefit (SCB) after orthopaedic surgical procedures. Data pertaining to demographic characteristics, subspecialty, specific ML algorithms, and algorithm performance were analyzed., Results: Eighteen articles met the inclusion criteria. Seventeen studies developed novel algorithms, whereas one study externally validated an established algorithm. All studies used ML to predict MCID achievement, whereas 3 (16.7%) predicted SCB achievement and none predicted PASS achievement. Of the studies, 7 (38.9%) concerned outcomes after spine surgery; 6 (33.3%), after sports medicine surgery; 3 (16.7%), after total joint arthroplasty (TJA); and 2 (11.1%), after shoulder arthroplasty. No studies were found regarding trauma, hand, elbow, pediatric, or foot and ankle surgery. In spine surgery, concordance statistics (C-statistics) ranged from 0.65 to 0.92; in hip arthroscopy, 0.51 to 0.94; in TJA, 0.63 to 0.89; and in shoulder arthroplasty, 0.70 to 0.95. Most studies reported C-statistics at the upper end of these ranges, although populations were heterogeneous., Conclusions: Currently available ML algorithms can discriminate the propensity to achieve CSOs using the MCID after spine, TJA, sports medicine, and shoulder surgery with a fair to good performance as evidenced by C-statistics ranging from 0.6 to 0.95 in most analyses. Less evidence is available on the ability of ML to predict achievement of SCB, and no evidence is available for achievement of the PASS. Such algorithms may augment shared decision-making practices and allow clinicians to provide more appropriate patient expectations using individualized risk assessments. However, these studies remain limited by variable reporting of performance metrics, CSO quantification methods, and adherence to predictive modeling guidelines, as well as limited external validation., Level of Evidence: Level III, systematic review of Level III studies., (Copyright © 2021 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)