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Brian T Kelly,1 Jonathan S Tam,1 James W Verbsky,1,2 John M Routes1,2 1Department of Pediatrics, 2Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA Abstract: Severe combined immunodeficiency (SCID) is a rare disease that severely affects the cellular and humoral immune systems. Patients with SCID present with recurrent or severe infections and often with chronic diarrhea and failure to thrive. The disease is uniformly fatal, making early diagnosis essential. Definitive treatment is hematopoietic stem cell transplantation, with best outcomes prior to 3.5 months of age. Newborn screening for SCID using the T-cell receptor excision circle assay has revolutionized early identification of infants with SCID or severe T-cell lymphopenia. Keywords: severe combined immunodeficiency, T-cell receptor excision circle, newborn screening, primary immunodeficiency

Both arthroscopic and open operative treatment of femoroacetabular impingement (FAI) can reproducibly relieve hip pain with correction of the underlying osseous deformity and treatment of the associated labral pathology, particularly in patients without substantial articular cartilage injury at the time of surgery. Between 75% and 90% of athletes undergoing FAI surgery return to sports at their pre-injury level of function. There is no peer-reviewed evidence to date reporting on the efficacy of nonoperative treatment and return to play with FAI. Successful operative treatment of impingement requires appropriate and complete correction of the mechanical injury that led to the symptomatic labral pathology. Early intervention prior to the onset of irreversible chondral damage is critical to the long-term success of FAI surgery. Complex deformities involving combinations of static and dynamic mechanical factors often coexist, so careful preoperative evaluation of the underlying structural anatomy is critical to successful treatment planning. [ABSTRACT FROM AUTHOR]

Background: The overhead athlete is at risk for shoulder and elbow injuries. However, the mechanics associated with overhead sports also place athletes at risk for hip injuries. Advancements in hip arthroscopy have identified femoroacetabular impingement (FAI) and instability as potential contributors to labral and chondral pathology in this athletic population.Questions/purposes: We therefore determined whether hip function improves after arthroscopic treatment of FAI in overhead athletes and the rate at which overhead athletes returned to preinjury level of play.Methods: We retrospectively identified high-level baseball and lacrosse players (varsity high school, collegiate, and professional) who underwent arthroscopic treatment for FAI. Thirty-four athletes with an average age of 21.4 years met study criteria. There were 16 baseball players and 18 lacrosse players. All patients completed modified Harris hip scores and were assessed for ability to return to preinjury level of play. The minimum followup was 12 months (average, 25 months; range 12-41 months).Results: Mean modified Harris hip scores improved from 70 to 92. Thirty-three of 34 patients were able to return to preinjury level of sports participation.Conclusions: Arthroscopic management of hip injuries in the high-level overhead throwing athlete can result in a high rate of return to play. Mechanical overload of the hip from impingement and secondary instability can have a substantial effect on hip function and may be the cause of deterioration in athletic performance in some cases.Level Of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Despite its highly specialized nature, articular cartilage has a poor reparative capability. Treatment of symptomatic osteochondral defects of the talus has been especially difficult until now.Methods: We performed autologous chondrocyte transplantation in twelve patients with a focal deep cartilage lesion of the talus. There were seven female and five male patients with a mean age of 29.7 years. The mean size of the lesion was 2.3 cm(2). All patients were studied prospectively. Evaluation was performed with use of the Hannover ankle rating score, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, a visual analog scale for pain, and magnetic resonance imaging.Results: All patients were available for follow-up at a mean of sixty-three months. There was a significant improvement in the Hannover score, from 40.4 points preoperatively to 85.5 points at the follow-up examination, with seven excellent results, four good results, and one satisfactory result. The AOFAS mean score was 88.4 points compared with 43.5 points preoperatively. Magnetic resonance imaging showed a nearly congruent joint surface in seven patients, discrete irregularities in four, and an incongruent surface in one. The patients who had been involved in competitive sports were able to return to their full activity level.Conclusions: The promising clinical results of this study suggest that autologous chondrocyte transplantation is an effective and safe way to treat symptomatic osteochondral defects of the talus in appropriately selected patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Meniscal allograft transplantation has become a viable surgical alternative for a select group of patients with deficient or irreparable menisci. Subjective results are encouraging; long-term success, durability, and safety of allograft meniscal transplantation are uncertain. PURPOSES: To evaluate a novel hydrogel meniscal replacement implant in an ovine model and assess chondroprotective effects of this hydrogel meniscal replacement using several validated outcome measures. STUDY DESIGN: Controlled laboratory study. METHODS: Fourteen skeletally mature sheep underwent hydrogel meniscal replacement; 45 additional animals had previously undergone 1 of 3 operations: lateral meniscectomy (24), meniscal allograft transplant (17), and sham (4). Animals were sacrificed at 2, 4, or 12 months. Cartilage was assessed by magnetic resonance imaging, gross inspection, biomechanical testing, and semiquantitative histological analysis. RESULTS: There were no differences between the sham operation and nonoperated control limbs. Compared with meniscectomy, hydrogel meniscal replacement resulted in significantly decreased cartilage degeneration with all outcome parameters (P < .05). Compared with nonoperated control limbs, hydrogel meniscal replacements demonstrated no significant differences at 2 months in any category. By 4 months, hydrogel limbs demonstrated significantly greater cartilage degeneration than did nonoperated control limbs in all categories. Compared with meniscal allograft transplantation animals, hydrogel meniscal replacements demonstrated no differences at 2 months but had significantly increased cartilage degeneration in the peripheral zone of the tibial plateau at 4 months (P < .05). At 1 year, all hydrogel implants had developed complete radial splits in the posterior third of the implant. CONCLUSION: Although promising preliminary results for hydrogel meniscal replacement were seen at early time points, significant cartilage degeneration and implant failure were seen at 1 year, and overall performance was worse than was allograft transplantation. Improvements in hydrogel material properties and surface characteristics and more accurate size matching may improve outcomes. CLINICAL RELEVANCE: Improvements in the hydrogel material properties and surface characteristics and more accurate size matching may lead to the use of hydrogel implants in humans. [ABSTRACT FROM AUTHOR]

BACKGROUND: Early protection of articular cartilage, before degenerative changes appear on radiographs, should result in better long-term results, but scientific evidence regarding the effectiveness of meniscal transplantation is lacking. PURPOSE: To assess the chondroprotective effects of a new meniscal allograft transplantation animal model and evaluate a magnetic resonance imaging parameter, T2 mapping, in articular cartilage after meniscectomy and meniscal transplantation. STUDY DESIGN: Controlled laboratory study. METHODS: Forty-five skeletally mature sheep were placed into 3 surgical groups: lateral meniscectomy (n = 24), meniscal allograft transplant (n = 17), and sham (n = 4). Animals were sacrificed at 2, 4, or 12 months. Cartilage was assessed by gross inspection, magnetic resonance imaging, T2 mapping, biomechanical testing, and semiquantitative histologic analysis. RESULTS: There were no differences between the sham operation and nonoperated control limbs. Compared with control limbs, meniscectomy resulted in significant increases in cartilage degeneration by all objective criteria (P < .01). Compared with meniscectomy, meniscal allograft transplantation resulted in significant decreases in cartilage degeneration (P < .02). There were significant correlations between T2-mapping data and all other traditional outcomes measures (P < .05, r(2) = 0.37-0.67). Compared with the nonoperated control limbs, allograft transplants demonstrated no significant differences at 2 months in any category, except magnetic resonance imaging data. By 4 months, nonoperated control limbs demonstrated significantly less wear compared to allograft limbs in all categories except modified Mankin scores. CONCLUSION: This model demonstrated significant chondroprotection compared with meniscectomy but demonstrated more cartilage wear at 4 months compared to control limbs. A high degree of allograft cell viability and vascular ingrowth was seen in allograft explants. T2 mapping may provide an accurate noninvasive measure of early cartilage degeneration after meniscectomy, as well as cartilage protection after meniscal allograft transplantation. CLINICAL RELEVANCE: This study establishes a reliable animal model for meniscal allograft transplantation and provides evidence for the utility of T2 mapping at clinically relevant magnetic resonance imaging field strengths for evaluation of early cartilage degeneration. [ABSTRACT FROM AUTHOR]

Background: Combined latissimus dorsi and teres major musculotendinous transfer has been described for the treatment of massive rotator cuff deficits. The procedure is technically complex because of the proximity of the radial nerve, the axillary nerve and its posterior branches, and the neurovascular bundles to the muscles. The purpose of the present cadaveric study was to examine surgically relevant relationships for latissimus dorsi and teres major tendon transfers.Methods: Twelve cadaveric shoulder girdles were dissected, and the latissimus dorsi, the teres major, and the posterior cord of the brachial plexus and its branches were identified. The relationships between the tendons and local neurologic structures were measured during various steps of the latissimus dorsi/teres major transfer procedure. The effect of humeral rotation on the exposure of the latissimus dorsi and teres major tendons through the posterior approach was quantified, and relevant surgical landmarks were described.Results: The radial nerve passed directly anterior to the tendons at an average of 2.9 cm medial to the superior aspect and 2.3 cm medial to the inferior aspect of the humeral insertions. From the posterior axillary approach, maximal internal rotation facilitated exposure for tenotomy by delivering the tendon insertions on the humerus into the surgical field. During axial mobilization of the musculotendinous units, the neurovascular pedicles to the latissimus dorsi and teres major were identified at an average of 13.1 and 7.4 cm axial to the humeral insertions, respectively. The posterior branch of the axillary nerve was noted to cross superficially over the transferred tendons as they were tunneled under the posterior deltoid.Conclusions: Multiple steps of the combined latissimus dorsi and teres major musculotendinous transfer place local neurologic structures at risk. These steps include tendon release, musculotendinous axial mobilization, and tendon tunneling in the plane between the infraspinatus-teres minor and the posterior deltoid. We have quantified and described the relationship of the axillary and radial nerves to the tendons during tenotomy, the distance from the tendons' insertions to their neurovascular bundle that must be identified during axial mobilization, and the course of the posterior branch of the axillary nerve in relation to the tunneled path of the tendons.Clinical Relevance: The present study provides important anatomic findings for the safe mobilization and transfer of the latissimus dorsi and teres major tendons during the surgical treatment of irreparable rotator cuff tears. [ABSTRACT FROM AUTHOR]

The electromyographic activity of eight muscles of the rotator cuff and shoulder girdle (supraspinatus, infraspinatus, subscapularis, pectoralis, latissimus dorsi, and the anterior, middle, and posterior deltoid) was measured from the nondominant shoulders of 11 subjects during a series of 29 isometric contractions. The contractions simulated different positions used for strength testing of the rotator cuff and involved elevation, external rotation, and internal rotation at three degrees of initial humeral rotation (-45 degrees of internal rotation, 0 degrees, +45 degrees of external rotation) and scapular elevation (0 degrees, 45 degrees, 90 degrees). Isolation of the supraspinatus muscle was best achieved with the test position of elevation at 90 degrees of scapular elevation and +45 degrees (external rotation) of humeral rotation. Isolation of the infraspinatus muscle was best achieved with external rotation at 0 degrees of scapular elevation and -45 degrees (internal rotation) of humeral rotation. Isolation of the subscapularis muscle was best achieved with the Gerber push-off test. This study used four criteria for identifying the optimal manual muscle test for each rotator cuff muscle: 1) maximal activation of the cuff muscle, 2) minimal contribution from involved shoulder synergists, 3) minimal provocation of pain, and 4) good test-retest reliability. Based on the results of this study and known painful arcs of motion, an objective identification of the optimal tests for the manual muscle testing of the cuff was elucidated. [ABSTRACT FROM AUTHOR]

Background: Hip abductor deficiency is a common cause of lateral hip pain in middle-aged patients. Identifying upstream muscle denervation originating in the lumbo-sacral spine could potentially impact the management of patients who have abductor deficiency. The purpose of this study was to estimate the prevalence of lumbo-sacral pathology (L4 to S1) in patients undergoing hip abductor tendon repair., Methods: All cases of primary hip abductor repair performed at a tertiary care center between January 2010 and December 2021 were reviewed. Patients were classified into the following groups: A) confirmed L4 to S1 disease based on preoperative or perioperative L4 to S1 interventions (ie, surgery, epidural injections, and/or positive electromyography findings); B) radiographic evidence on lumbar spine magnetic resonance imaging demonstrating nerve compression at L4 to S1; and C) no evidence of L4 to S1 disease., Results: There were 131 cases of primary hip abductor repair that were included. Over 80% of patients were women, who had a mean age of 64 years (range, 20 to 85). There were thirteen patients (9.9%) who underwent concomitant total hip arthroplasty (THA). Of the included patients, 29% (n = 38) were categorized into group A, 12% (n = 16) into group B, and 59% (n = 77) into group C. Patients who had L4 to S1 pathology were older than patients who did not have L4 to S1 pathology (67 versus 61 years, P = .004). Of the patients undergoing concomitant THA and hip abductor repair, 54% demonstrated evidence of lumbo-sacral spine pathology., Conclusions: Over 40% of patients undergoing isolated hip abductor tendon repair and >50% of patients undergoing concomitant hip abductor tendon repair and THA demonstrated evidence of L4 to S1 disease perioperatively. Patients demonstrating symptomatic hip abductor deficiency should be screened for concomitant lower lumbo-sacral spine pathology., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Primary anterior cruciate ligament (ACL) repair has gained renewed interest in select centers for patients with proximal or midsubstance ACL tears. Therefore, it is important to reassess contemporary clinical outcomes of ACL repair to determine whether a clinical benefit exists over the gold standard of ACL reconstruction (ACLR)., Purpose: To (1) perform a meta-analysis of comparative trials to determine whether differences in clinical outcomes and adverse events exist between ACL repair versus ACLR and (2) synthesize the midterm outcomes of available trials., Study Design: Systematic review; Level of evidence, 3., Methods: The PubMed, OVID/Medline, and Cochrane databases were queried in August 2023 for prospective and retrospective clinical trials comparing ACL repair and ACLR. Data pertaining to tear location, surgical technique, adverse events, and clinical outcome measures were recorded. DerSimonian-Laird random-effects models were constructed to quantitatively evaluate the association between ACL repair/ACLR, adverse events, and clinical outcomes. A subanalysis of minimum 5-year outcomes was performed., Results: Twelve studies (893 patients; 464 ACLR and 429 ACL repair) were included. Random-effects models demonstrated a higher relative risk (RR) of recurrent instability/clinical failure (RR = 1.64; 95% confidence interval [CI], 1.04-2.57; P  = .032), revision ACLR (RR = 1.63; 95% CI, 1.03-2.59; P  = .039), and hardware removal (RR = 4.94; 95% CI, 2.10-11.61; P  = .0003) in patients who underwent primary ACL repair versus ACLR. The RR of reoperations and complications (knee-related) were not significantly different between groups. No significant differences were observed when comparing patient-reported outcome scores. In studies with minimum 5-year outcomes, no significant differences in adverse events or Lysholm scores were observed., Conclusion: In contemporary comparative trials of ACL repair versus ACLR, the RR of clinical failure, revision surgery due to ACL rerupture, and hardware removal was greater for primary ACL repair compared with ACLR. There were no observed differences in patient-reported outcome scores, reoperations, or knee-related complications between approaches. In the limited literature reporting on minimum 5-year outcomes, significant differences in adverse events or the International Knee Documentation Committee score were not observed., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A.P. has received education payments from Smith+Nephew and hospitality payments from Medical Device Business Services. B.U.N. has received grant support from Arthrex, education payments from Arthrex and Smith+Nephew, consulting fees from Stryker, and hospitality payments from Medical Device Business Services and Zimmer Biomet. A.S.R. has received education payments from Gotham Surgical; consulting fees from Anika Therapeutics, Bodycad, Smith+Nephew, Xiros, Stryker, Flexion Therapeutics, Arthrex, and Heron Therapeutics; and nonconsulting fees from Arthrex and Smith+Nephew. A.S.P. has received consulting fees from Smith+ Nephew, Zimmer Biomet, DePuy Synthes, Exactech, and Stryker; nonconsulting fees from Smith+Nephew; royalties from Smith+Nephew and Zimmer Biomet; and has stock/stock options in Smith+Nephew. B.T.K. has received education payments from Arthrex; consulting fees from Arthrex; nonconsulting fees from Arthrex and Synthes; royalties from Arthrex; and hospitality payments from Stryker and Smith+Nephew. R.J.W. has received royalty or license from Arthrex; consulting fees and nonconsulting fees from Arthrex; and has stock/stock options in Smith+Nephew. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2024.)

Purpose: To develop a deep learning model for the detection of Segond fractures on anteroposterior (AP) knee radiographs and to compare model performance to that of trained human experts., Methods: AP knee radiographs were retrieved from the Hospital for Special Surgery ACL Registry, which enrolled patients between 2009 and 2013. All images corresponded to patients who underwent anterior cruciate ligament reconstruction by 1 of 23 surgeons included in the registry data. Images were categorized into 1 of 2 classes based on radiographic evidence of a Segond fracture and manually annotated. Seventy percent of the images were used to populate the training set, while 20% and 10% were reserved for the validation and test sets, respectively. Images from the test set were used to compare model performance to that of expert human observers, including an orthopaedic surgery sports medicine fellow and a fellowship-trained orthopaedic sports medicine surgeon with over 10 years of experience., Results: A total of 324 AP knee radiographs were retrieved, of which 34 (10.4%) images demonstrated evidence of a Segond fracture. The overall mean average precision (mAP) was 0.985, and this was maintained on the Segond fracture class (mAP = 0.978, precision = 0.844, recall = 1). The model demonstrated 100% accuracy with perfect sensitivity and specificity when applied to the independent testing set and the ability to meet or exceed human sensitivity and specificity in all cases. Compared to an orthopaedic surgery sports medicine fellow, the model required 0.3% of the total time needed to evaluate and classify images in the independent test set., Conclusions: A deep learning model was developed and internally validated for Segond fracture detection on AP radiographs and demonstrated perfect accuracy, sensitivity, and specificity on a small test set of radiographs with and without Segond fractures. The model demonstrated superior performance compared with expert human observers., Clinical Relevance: Deep learning can be used for automated Segond fracture identification on radiographs, leading to improved diagnosis of easily missed concomitant injuries, including lateral meniscus tears. Automated identification of Segond fractures can also enable large-scale studies on the incidence and clinical significance of these fractures, which may lead to improved management and outcomes for patients with knee injuries., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: J.F.O. is a consultant or advisor for Kaliber.ai. B.U.N. is a consultant or advisor for 10.13039/100008894Stryker, has equity or stocks with Remote Health, and is a board member of Figur8 and BICMD. H.G.G. is a consultant or advisor for Motion Orthopaedics and Professional Imaging and has equity or stocks with Tate Greditzer, LLC. C.L.C. is a paid consultant for 10.13039/100007307Arthrex, has received research support from 10.13039/100007062Major League Baseball, and has received publishing royalties and financial or material support from Springer. B.T.K. is a consultant or advisor for 10.13039/100007307Arthrex and BICMD. A.D.P. is a consultant or advisor for DePuy Synthes, Exactech, Smith & Nephew, and 10.13039/100006338Zimmer and has equity or stocks with ACLIP, myHealthTrack, PerfectFict, and Vent Creativity. A.S.R. is a consultant or advisor for 10.13039/100014927Anika Therapeutics, 10.13039/100007307Arthrex, Bodycad USA, Marrow Cellution, Newclip Technics, Smith & Nephew, 10.13039/100008894Stryker, and Xiros; has received speaking and lecture fees from Arthrex; and has equity or stocks with Conformis, Enhatch, and Ranfac. R.J.W. has equity or stocks with BICMD, CyMedica Orthopedics, Gramercy Extremity Orthopedics, Remote Health Ventures, Tonal, and Overture and is a board member of Pristine Surgical, Rehab Boost, and Tonal. All other authors (A.P., K.N.K.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Background: Little is known about the effect of modern hip arthroscopy on the natural history of femoroacetabular impingement syndrome (FAIS) with respect to joint preservation., Purpose: To (1) characterize the natural history of FAIS and (2) understand the effect of modern hip arthroscopy by radiographically comparing the hips of patients who underwent only unilateral primary hip arthroscopy with a minimum follow-up of 10 years., Study Design: Cohort study; Level of evidence, 3., Methods: Between 2010 and 2012, 619 consecutive patients were reviewed from the practice of a single fellowship-trained hip arthroscopic surgeon. Inclusion criteria were FAIS, bilateral radiographic findings of femoroacetabular impingement, primary unilateral hip arthroscopy (labral repair, femoroplasty, or capsular closure), and minimum 10-year follow-up. The preoperative and minimum 10-year postoperative radiographs of patients were evaluated at each time point. Both operative and nonoperative hips were graded using the Tönnis classification or the presence of hip arthroplasty by 2 independent reviewers. Subgroup analyses were performed., Results: A total of 200 hips from 100 patients were evaluated at a mean follow-up of 12.0 years. Preoperatively, 98% and 99% of operative and nonoperative hips were evaluated as Tönnis grades 0 and 1, respectively; 5% of nonoperative hips had worse Tönnis grades than operative hips. The nonoperative hip advanced to a worse Tönnis grade in 48% (48/100) of cases compared with 28% (28/100) among operative hips. At follow-up, Tönnis grades between hips were equal in 70% (70/100) of the cases, the operative hip had a better grade 25% (25/100) of the time, and the nonoperative hip had a better grade 5% (5/100) of the time. Modern hip arthroscopy was associated with a relative risk reduction of 42% in osteoarthritis progression. Impingement with borderline dysplasia, age, preoperative Tönnis grade, and alpha angle >65° were key risk factors in the radiographic progression of osteoarthritis., Conclusion: Although the majority of patients (70%) undergoing hip arthroscopy for FAIS did not experience differences between operative and nonoperative hips in terms of the radiographic progression of osteoarthritis, the natural history may be favorably altered for 25% of patients whose Tönnis grade was better after undergoing arthroscopic correction. Modern hip arthroscopy indications and techniques represent a valid joint-preservation procedure conferring a relative risk reduction of 42% in the progression of osteoarthritis. Arthroscopy for mixed patterns of impingement and instability were the fastest to degenerate., Competing Interests: One or more of the authors has declared the following potential conflicts of interest or source of funding. P.N.R. has received consulting fees from Pacira; hospitality payments from Stryker; consulting fees and royalties from Globus; research support from Arthrex; and support for education from Smith & Nephew and has ownership in Intelligent Health Analytics Inc and Overture. D.H.N. has received consulting fees from Linvatec Corporation; hospitality payments from Stryker and Arthrex; support for education from Gotham Surgical Solutions & Devices; and royalties from Smith & Nephew. B.T.K. has received consulting fees and royalties from Arthrex; hospitality payments from Stryker; and faculty or speaker fees from Synthes GmbH. AJSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Purpose: To (1) compare the efficacy of immersive virtual reality (iVR) to nonimmersive virtual reality (non-iVR) training in hip arthroscopy on procedural and knowledge-based skills acquisition and (2) evaluate the relative cost of each platform., Methods: Fourteen orthopaedic surgery residents were randomized to simulation training utilizing an iVR Hip Arthroscopy Simulator (n = 7; PrecisionOS) or non-iVR simulator (n = 7; ArthroS Hip VR; VirtaMed). After training, performance was assessed on a cadaver by 4 expert hip arthroscopists through arthroscopic video review of a diagnostic hip arthroscopy. Performance was assessed using the Objective Structured Assessment of Technical Skills (OSATS) and Arthroscopic Surgery Skill Evaluation Tool (ASSET) scores. A cost analysis was performed using the transfer effectiveness ratio (TER) and a direct cost comparison of iVR to non-iVR., Results: Demographic characteristics did not differ between treatment arms or by training level, hip arthroscopy experience, or prior simulator use. No significant differences were observed in OSATS and ASSET scores between iVR and non-iVR cohorts (OSATS: iVR 19.6 ± 4.4, non-iVR 21.0 ± 4.1, P = .55; ASSET: iVR 23.7 ± 4.5, non-iVR 25.8 ± 4.8, P = .43). The absolute TER was 0.06 and there was a 132-fold cost difference of iVR to non-iVR., Conclusions: Hip arthroscopy simulator training with iVR had similar performance results to non-iVR for technical skill and procedural knowledge acquisition after expert arthroscopic video assessment. The iVR platform had similar effectiveness in transfer of skill compared to non-iVR with a 132 times cost differential. CLINICAL RELEVANCE: Due to the accessibility, effectiveness, and relative affordability, iVR training may be beneficial in the future of safe arthroscopic hip training., Competing Interests: Disclosures The authors report the following potential conflicts of interest or sources of funding: This project received the Arthroscopy Association of North America (AANA) 2022 Research Grant. O.F.R. has received grants from the Arthroscopy Association of North America during the conduct of the study, has received personal fees from Arthrex outside the submitted work, and is on the editorial or governing board for the Journal of Orthopaedic Experience and Innovation. K.K. is on the editorial or governing board for Arthroscopy. A.S.R. has received personal fees from Anika, Bodycad, Cervos, Enhatch, Moximed, NewClip, Ranfac, and Smith & Nephew outside the submitted work; has received grants from Depuy Mitek-Synthes; has a patent with DePuy, a Johnson & Johnson Company with royalties paid; is a board or committee member of the AAOS, American Orthopaedic Society for Sports Medicine, and EOA; and is on the editorial or governing board for the American Journal of Sports Medicine, Current Trends in Musculoskeletal Medicine, Journal of Arthroplasty, Saunders/Mosby-Elsevier, and Springer. M.B.B. has received grants and/or personal fees from Arthrex, Smith & Nephew, Stryker, and Vericel, outside the submitted work, and is board or committee member of the American Orthopaedic Society for Sports Medicine, Arthroscopy Association of North America, Hip Society, and ICJR. B.T.K. has received personal fees from HS2 and other financial or material support from IPT, MMI, Organicell, Parvizi Surgical, and Relief Labs, outside the submitted work. G.J.G. has received personal fees from Stryker, outside the submitted work, and is on the editorial or governing board for the Journal of the American Academy of Orthopaedic Surgeons and Orthopedics. All other 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.)

Deep learning is a subset of artificial intelligence (AI) with enormous potential to transform orthopaedic surgery. As has already become evident with the deployment of Large Language Models (LLMs) like ChatGPT (OpenAI Inc.), deep learning can rapidly enter clinical and surgical practices. As such, it is imperative that orthopaedic surgeons acquire a deeper understanding of the technical terminology, capabilities and limitations associated with deep learning models. The focus of this series thus far has been providing surgeons with an overview of the steps needed to implement a deep learning-based pipeline, emphasizing some of the important technical details for surgeons to understand as they encounter, evaluate or lead deep learning projects. However, this series would be remiss without providing practical examples of how deep learning models have begun to be deployed and highlighting the areas where the authors feel deep learning may have the most profound potential. While computer vision applications of deep learning were the focus of Parts I and II, due to the enormous impact that natural language processing (NLP) has had in recent months, NLP-based deep learning models are also discussed in this final part of the series. In this review, three applications that the authors believe can be impacted the most by deep learning but with which many surgeons may not be familiar are discussed: (1) registry construction, (2) diagnostic AI and (3) data privacy. Deep learning-based registry construction will be essential for the development of more impactful clinical applications, with diagnostic AI being one of those applications likely to augment clinical decision-making in the near future. As the applications of deep learning continue to grow, the protection of patient information will become increasingly essential; as such, applications of deep learning to enhance data privacy are likely to become more important than ever before. Level of Evidence: Level IV., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

The exquisite specificity of antibodies can be harnessed to effect targeted degradation of membrane proteins. Here, we demonstrate targeted protein removal utilising a protein degradation domain derived from the endogenous human protein Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9). Recombinant antibodies genetically fused to this domain drive the degradation of membrane proteins that undergo constitutive internalisation and recycling, including the transferrin receptor and the human cytomegalovirus latency-associated protein US28. We term this approach PACTAC (PCSK9-Antibody Clearance-Targeting Chimeras)., (© 2024. The Author(s).)

Purpose: To (1) review definitions and concepts necessary to interpret applications of deep learning (DL; a domain of artificial intelligence that leverages neural networks to make predictions on media inputs such as images) and (2) identify knowledge and translational gaps in the literature to provide insight into specific areas for improvement as adoption of this technology continues., Methods: A comprehensive search of the literature was performed in December 2023 for articles regarding the use of DL in sports medicine. For each study, information regarding the joint of focus, specific anatomic structure/pathology to which DL was applied, imaging modality utilized, source of images used for model training and testing, data set size, model performance, and whether the DL model was externally validated was recorded. A numerical scale was used to rate each DL model's clinical impact, with 1 corresponding to proof-of-concept studies with little to no direct clinical impact and 5 corresponding to practice-changing clinical impact and ready for clinical deployment., Results: Fifty-five studies were identified, all of which were published within the past 5 years, while 82% were published within the past 3 years. Of the DL models identified, 84% were developed for classification tasks, 9% for automated measurements, and 7% for segmentation. A total of 62% of studies utilized magnetic resonance imaging as the imaging modality, 25% radiographs, and 7% ultrasound, while 1 study each used computed tomography, arthroscopic images, or arthroscopic video. Sixty-five percent of studies focused on the detection of tears (anterior cruciate ligament [ACL], rotator cuff [RC], and meniscus). The diagnostic performance of ACL tears, as determined by the area under the receiver operator curve (AUROC), ranged from 0.81 to 0.99 for ACL tears (excellent to near perfect), 0.83 to 0.94 for RC tears (excellent), and from 0.75 to 0.96 for meniscus tears (acceptable to excellent). In addition, 3 studies focused on detection of cartilage lesions had AUROC ranging from 0.90 to 0.92 (excellent performance). However, only 4 (7%) studies externally validated their models, suggesting that they may not be generalizable or may not perform well when applied to populations other than that used to develop the model. Finally, the mean clinical impact score was 2 (range, 1-3) on scale of 1 to 5, corresponding to limited clinical applicability., Conclusions: DL models in orthopaedic sports medicine show generally excellent performance (high internal validity) but require external validation to facilitate clinical deployment. In addition, current models have low clinical applicability and fail to advance the field due to a focus on routine tasks and a narrow conceptual framework., Level of Evidence: Level IV, scoping review of Level I to IV studies., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine return to soccer rates and soccer performance in a large cohort of competitive soccer players after hip arthroscopic surgery for the treatment of femoroacetabular impingement (FAI) and to identify possible risk factors associated with not returning to soccer., Methods: An institutional hip preservation registry was retrospectively reviewed for patients identified as competitive soccer players who underwent primary hip arthroscopy for FAI performed between 2010 and 2017. Patient demographics and injury characteristics as well as clinical and radiographic findings were recorded. All patients were contacted for return to soccer information using a soccer-specific return to play questionnaire. Multivariable logistic regression analysis was used to identify potential risk factors for not returning to soccer., Results: Eighty-seven competitive soccer players (119 hips) were included. 32 players (37%) underwent simultaneous or staged bilateral hip arthroscopy. The mean age at surgery was 21.6 ± 7.0 years. Overall, 65 players (74.7%) returned to soccer, of which 43 players (49% of all included players) returned to pre-injury level of play or better. Most common reasons for not returning to soccer were pain or discomfort (50%) followed by fear of re-injury (31.8%). The mean time to return to soccer was 33.1 ± 26.3 weeks. Among 22 players who did not return to soccer, 14 (63.6%) reported satisfaction from surgery. Multivariable logistic regression analysis revealed female players (odds ratio [OR] = 0.27; confidence interval [CI] = 0.083 to 0.872; p = 0.029) and older aged players (OR = 0.895; 95% CI = 0.832 to 0.963; p = 0.003) were less likely to return to soccer. Bilateral surgery was not found to be a risk factor., Conclusion: Hip arthroscopic treatment for FAI in symptomatic competitive soccer players allowed three-quarters of them to return to soccer. Despite not returning to soccer, two-thirds of players who did not return to soccer were satisfied with their outcome. Female and older aged players were less likely to return to soccer. These data can better guide clinicians and soccer players with realistic expectations related to the arthroscopic management of symptomatic FAI., Level of Evidence: III., (© 2023. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

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.)

Background: Outcomes after isolated hip arthroscopic surgery for patients with dysplasia have been unfavorable. Results have included iatrogenic instability and conversion to total hip arthroplasty at a young age. However, patients with borderline dysplasia (BD) have shown more favorable results at short- and medium-term follow-up., Purpose: To assess long-term outcomes after hip arthroscopic surgery for femoroacetabular impingement in patients with BD (lateral center-edge angle [LCEA] = 18°-25°) compared with a control group of patients without dysplasia (LCEA = 26°-40°)., Study Design: Cohort study; Level of evidence, 3., Methods: We identified a group of 33 patients (38 hips) with BD who were treated for FAI between March 2009 and July 2012. An age- and sex-matched control group of 83 patients (96 hips) was also identified. Patient-reported outcome scores were collected preoperatively and subsequently at a mean of 9.6 years postoperatively., Results: The mean LCEA and Tönnis angle were 22.42°± 2.02° and 6.27°± 3.23° in the BD group, respectively, and 31.71°± 3.52° and 2.42°± 3.02° in the control group, respectively ( P < .001). At a mean follow-up of 9.6 years (range, 8.2-11.6 years), there was a significant improvement in all patient-reported outcome scores in both groups ( P < .001). There were no significant differences between preoperative and postoperative scores or rates of achieving the minimal clinically important difference between the BD and control groups. Bilateral surgery was noted to be a risk factor for any revision during the follow-up period ( P < .001). There were 2 hips (5.3%) that underwent revision surgery in the BD group and 10 hips (10.4%) in the control group; of these, 1 patient in the BD group underwent total hip arthroplasty, and 1 patient who had undergone bilateral surgery in the control group underwent bilateral hip resurfacing., Conclusion: Durable outcomes (>9 years) with low revision rates can be expected after hip arthroscopic surgery with an approach that involves labral preservation where possible and careful attention to capsular closure in patients with BD. The observed outcomes were similar to those of a femoroacetabular impingement group with normal coverage. These results highlight the importance of classifying patients into impingement or instability categories and tailoring treatment appropriately with arthroscopic surgery or periacetabular osteotomy, respectively.

Deep learning has the potential to be one of the most transformative technologies to impact orthopedic surgery. Substantial innovation in this area has occurred over the past 5 years, but clinically meaningful advancements remain limited by a disconnect between clinical and technical experts. That is, it is likely that few orthopedic surgeons possess both the clinical knowledge necessary to identify orthopedic problems, and the technical knowledge needed to implement deep learning-based solutions. To maximize the utilization of rapidly advancing technologies derived from deep learning models, orthopedic surgeons should understand the steps needed to design, organize, implement, and evaluate a deep learning project and its workflow. Equipping surgeons with this knowledge is the objective of this three-part editorial review. Part I described the processes involved in defining the problem, team building, data acquisition, curation, labeling, and establishing the ground truth. Building on that, this review (Part II) provides guidance on pre-processing and augmenting the data, making use of open-source libraries/toolkits, and selecting the required hardware to implement the pipeline. Special considerations regarding model training and evaluation unique to deep learning models relative to "shallow" machine learning models are also reviewed. Finally, guidance pertaining to the clinical deployment of deep learning models in the real world is provided. As in Part I, the focus is on applications of deep learning for computer vision and imaging., (© 2023. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Background: It is currently unknown whether the addition of arthroscopic labral repair in the setting of periacetabular osteotomy (PAO) provides any clinical benefit., Purpose/hypothesis: The purpose of this study was to compare outcomes of patients who underwent arthroscopic labral repair concomitantly with PAO versus patients who underwent PAO alone. We hypothesized that there would be no difference in patient-reported outcome measures (PROMs) between the cohorts., Study Design: Cohort study; Level of evidence, 3., Methods: Patients undergoing PAO from a single-center prospective hip preservation registry were eligible for this study if they completed pre- and postoperative PROMs (minimum, 1 year). PROMs were collected at 1 year, 2 years, and latest follow-up at 6.05 years for PAO group and 4.2 years for scope/PAO group. The study group consisted of 53 patients who underwent arthroscopic labral repair at the time of their PAO, and the comparison group consisted of 170 patients who underwent PAO alone. A subset of the PAO group who had radiologic evidence of a detached labral tear (n = 33) was also compared with the rest of the PAO-alone group. PROMs were compared at every time point for both groups as well as the subset of patients who underwent PAO alone despite a labral tear., Results: The mean follow-up of all patients was 2 years (range, 1-6 years). Overall, 85.2% of the PAO group and 85.7% of the scope/PAO group met the minimal clinically important difference for either the modified Harris Hip Score (mHHS) or the International Hip Outcome Tool (iHOT-33) at the most recent follow-up. There was no difference in improvement between groups (mHHS, P = .670; iHOT-33, P = .944). Patients who had a radiologically diagnosed detached labral tear and underwent PAO alone had no difference in outcomes when compared with the rest of the PAO cohort (mHHS, P = .981; iHOT-33, P = .909)., Conclusion: There was no significant benefit measured by PROMs at follow-up for concomitant arthroscopic labral repair in the setting of PAO.

Natural language processing (NLP) describes the broad field of artificial intelligence by which computers are trained to understand and generate human language. Within healthcare research, NLP is commonly used for variable extraction and classification/cohort identification tasks. While these tools are becoming increasingly popular and available as both open-source and commercial products, there is a paucity of the literature within the orthopedic space describing the key tasks within these powerful pipelines. Curation and navigation of the electronic medical record are becoming increasingly onerous, and it is important for physicians and other healthcare professionals to understand potential methods of harnessing this large data resource. The purpose of this study is to provide an overview of the tasks required to develop an NLP pipeline for orthopedic research and present recent examples of successful implementations., (© 2022. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

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.)

Background: Individualized risk prediction has become possible with machine learning (ML), which may have important implications in enhancing clinical decision making. We previously developed an ML algorithm to predict propensity for clinically meaningful outcome improvement after hip arthroscopy for femoroacetabular impingement syndrome. External validity of prognostic models is critical to determine generalizability, although it is rarely performed., Purpose: To assess the external validity of an ML algorithm for predicting clinically meaningful improvement after hip arthroscopy., Study Design: Cohort study; Level of evidence, 3., Methods: An independent hip preservation registry at a tertiary academic medical center was queried for consecutive patients/athletes who underwent hip arthroscopy for femoroacetabular impingement syndrome between 2015 and 2017. By assuming a minimal clinically important difference (MCID) outcome/event proportion of 75% based on the original study, a minimum sample of 132 patients was required. In total, 154 patients were included. Age, body mass index, alpha angle on anteroposterior pelvic radiographs, Tönnis grade and angle, and preoperative Hip Outcome Score-Sports Subscale were used as model inputs to predict the MCID for the Hip Outcome Score-Sports Subscale 2 years postoperatively. Performance was assessed using identical metrics to the internal validation study and included discrimination, calibration, Brier score, and decision curve analysis., Results: The concordance statistic in the validation cohort was 0.80 (95% CI, 0.71 to 0.87), suggesting good to excellent discrimination. The calibration slope was 1.16 (95% CI, 0.74 to 1.61) and the calibration intercept 0.13 (95% CI, -0.26 to 0.53). The Brier score was 0.15 (95% CI, 0.12 to 0.18). The null model Brier score was 0.20. Decision curve analysis revealed favorable net treatment benefit for patients with use of the algorithm as compared with interventional changes made for all and no patients., Conclusion: The performance of this algorithm in an independent patient population in the northeast region of the United States demonstrated superior discrimination and comparable calibration to that of the derivation cohort. The external validation of this algorithm suggests that it is a reliable method to predict propensity for clinically meaningful improvement after hip arthroscopy and is an essential step forward toward introducing initial use in clinical practice. Potential uses include integration into electronic medical records for automated prediction, enhanced shared decision making, and more informed allocation of resources to optimize patient outcomes.

Background: The results of open hip abductor tendon repair remains poorly defined. We sought to present the results and complications of this procedure using modern suture anchor fixation., Materials and Methods: Our prospective institutional hip preservation registry was queried for all patients who underwent open hip abductor tendon repair with minimum 2-year follow-up were identified. Demographic, clinical, intraoperative, and functional outcome details were recorded. Patient-reported outcome scores (PROs) including the modified Harris Hip Score (mHHS), HOS-ADL, HOS-S, and iHOT-33 were collected for the preoperative and final postoperative state. Risk factors for lower final mHHS and change in mHHS were analysed using a multiple regression model., Results: A total of 21 patients with mean 48 months clinical follow-up (range 24-84 months). Median mHHS improved from 49.50 preoperatively to 82.50 postoperatively ( p  < 0.001), median HOS-ADL improved from 60.29 to 82.35 ( p  = 0.001), median HOS-S improved from 37.50 to 60.00 ( p  = 0.04), and median iHOT-33 improved from 29.81 to 70.15 ( p  = 0.001). All patients had +4 or +5 hip abductor strength at final in-person examination at mean 17 months postoperatively. All patients with a preoperative Trendelenburg gait had complete resolution at final examination. There 2 complications, and no patient had re-tear or revision surgery. LCEA < 25° and a history of prior ipsilateral hip surgery were independently predictive of smaller improvement in mHHS at final follow-up., Conclusions: Open abductor tendon repair is a safe and effective procedure that provides sustained symptomatic and functional improvements at mid-term follow-up.

Clathrin-mediated endocytosis (CME) is the main mechanism by which mammalian cells control their cell surface proteome. Proper operation of the pivotal CME cargo adaptor AP2 requires membrane-localized Fer/Cip4 homology domain-only proteins (FCHO). Here, live-cell enhanced total internal reflection fluorescence-structured illumination microscopy shows that FCHO marks sites of clathrin-coated pit (CCP) initiation, which mature into uniform-sized CCPs comprising a central patch of AP2 and clathrin corralled by an FCHO/Epidermal growth factor potential receptor substrate number 15 (Eps15) ring. We dissect the network of interactions between the FCHO interdomain linker and AP2, which concentrates, orients, tethers, and partially destabilizes closed AP2 at the plasma membrane. AP2's subsequent membrane deposition drives its opening, which triggers FCHO displacement through steric competition with phosphatidylinositol 4,5-bisphosphate, clathrin, cargo, and CME accessory factors. FCHO can now relocate toward a CCP's outer edge to engage and activate further AP2s to drive CCP growth/maturation.

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with high morbidity and limited treatment options. Type 2 diabetes mellitus (T2DM) is a common comorbid illness among patients with IPF and is often treated with metformin, the first-line agent in the management of T2DM. There is growing evidence demonstrating metformin's anti-fibrotic properties; however, there is little real-world clinical data regarding its potential effectiveness in IPF. This study aims to evaluate the clinical benefit of metformin in patients with IPF and T2DM., Methods: This nationwide cohort study used de-identified administrative claims data from OptumLabs® Data Warehouse to identify 3599 adults with IPF and concomitant T2DM between January 1, 2014 and June 30, 2019. Two cohorts were created: a cohort treated with metformin (n = 1377) and a cohort not treated with metformin (n = 2222). A final 1:1 propensity score-matched cohort compared 1100 patients with IPF and T2DM receiving metformin to those with both diagnoses but not receiving metformin; matching accounted for age, sex, race/ethnicity, residence region, year, medications, oxygen use, smoking status, healthcare use, and comorbidities. Outcomes were all-cause mortality (primary) and hospitalizations (secondary)., Results: Among 2200 patients with IPF and T2DM included in this matched analysis, metformin therapy was associated with a reduction in all-cause mortality (hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.36-0.58; p < 0.001) and hospitalizations (HR, 0.82; 95% CI, 0.72-0.93; p = 0.003) compared to patients not receiving metformin., Conclusions: Among patients with IPF and T2DM, metformin therapy may be associated with improved clinical outcomes. However, further investigation with randomized clinical trials is necessary prior to metformin's broad implementation in the clinical management of IPF., (© 2022. The Author(s).)

Purpose: The purpose of our study was to compare lower extremity rotational kinematics and kinetics (angles, torques, and powers) and hip muscle electromyography (EMG) activity between cam-type femoroacetabular impingement syndrome (FAIS) and age- and sex-matched controls during walking, fast walking, stair ascent, stair descent, and sit-to-stand., Methods: This study included 10 males with unilateral FAIS and 10 control males with no FAIS. We measured kinematics, kinetics, and electromyographic signals during stair ascent/descent, sit-to-stand, self-selected walk, and fast walk. Peak signal differences between groups were compared with independent t-tests with statistical significance when P < .05., Results: FAIS hips showed significant differences compared to controls, including increased hip flexion during walking (+4.9°, P = .048) and stair ascent (+7.8°, P =.003); diminished trunk rotation during stair ascent (-3.4°; P = .015), increased knee flexion during self-selected walking (+5.1°, P = .009), stair ascent (+7.4°, P = .001), and descent (+5.3°, P = .038); and increased knee valgus during fast walking (+4.7°, P = .038). gMed and MedHam showed significantly decreased activation in FAIS during walking (gMed: -12.9%, P = .002; MedHam: -7.4%, P = .028) and stair ascent (gMed: -16.7%, P = .036; MedHam: -13.0%, P = .041); decreased gMed activation during sit-to-stand (-8.8%, P = .004) and decreased MedHam activation during stair descent (-8.0%, P = .039)., Conclusions: Three-dimensional motion analysis and EMG evaluation of functional kinematics and kinetics in subjects with symptomatic unilateral cam-type FAIS across a spectrum of provocative tasks demonstrated significant differences compared to controls in hip flexion, trunk rotation, knee flexion, and valgus. FAIS hips had significantly decreased gMed and MedHam activity. These findings may explain altered torso-pelvic, hip, and knee mechanics in FAIS patients and suggest that evaluation of FAIS should include the patient's hip, knee, and torso-pelvic relationships and muscle function., Clinical Relevance: The clinical and functional manifestation of FAIS hip pathomechanics is not entirely understood, and previous literature to date has not clearly described the alterations in gait and functional movements seen in patients with cam-type FAIS. The current study used 3D motion analysis and EMG evaluation of functional kinematics and kinetics to identify a number of differences between FAIS and control hips, which help us better understand the lower extremity kinematics and kinetics and muscle activation in FAIS., (Copyright © 2021 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Background: The effect of interportal (IP) capsulotomy, short T-capsulotomy, and long T-capsulotomy, and their repairs, on resistance to anterior and posterior "at risk for dislocation" positions has not been quantified., Hypotheses: Our primary hypothesis was that an IP capsulotomy would have a minimal effect on hip resistive torque compared with both short and long T-capsulotomies in the at-risk dislocation positions. Our secondary hypothesis was that capsule repair would significantly increase hip resistive torque for all capsulotomies., Study Design: Controlled laboratory study., Methods: We mounted 10 cadaveric hips on a biaxial test frame in an anterior dislocation high-risk position (20° of hip extension and external rotation) and posterior dislocation high-risk position (90° of hip flexion and internal rotation). An axial force of 100 N was applied to the intact hip while the femur was internally or externally rotated at 15° per second to a torque of 5 N·m. The rotatory position at 5 N·m was recorded and set as a target for each subsequent condition. Hips were then sequentially tested with IP, short T-, and long T-capsulotomies and with corresponding repairs randomized within each condition. Peak resistive torques were compared using generalized estimating equation modeling and post hoc Bonferroni-adjusted tests., Results: For the anterior position, the IP and long T-capsulotomies demonstrated significantly lower resistive torques compared with intact. For the posterior position, both the short and long T-capsulotomies resulted in significantly lower resistive torques compared with intact. Repairs for all 3 capsulotomy types were not significantly different from the intact condition at anterior and posterior positions., Conclusion: An IP incision resulted in a decrease in capsular resistive torque in the anterior but not the posterior at-risk dislocation position, in which direction only T-capsulotomies led to a significant decrease. All capsulotomy repair conditions resulted in hip resistive torques that were similar to the intact hip in both dislocation positions., Clinical Relevance: Our results suggest that it is biomechanically advantageous to repair IP, short T-, and long T-capsulotomies, particularly for at-risk anterior dislocation positions., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: S.A.M. is the founder of, and has an ownership interest in, Agelity. B.T.K. has received consulting fees from Arthrex, Organicell, and Smith & Nephew; royalties from Arthrex; and hospitality payments from Stryker; and has stock/stock options in Organicell. A.R. has received education payments from Arthrex; consulting fees from Anika, Arthrex, Bodycad, ConforMIS, Enhatch, Flexion Therapeutics, Heron Therapeutics, Smith & Nephew, and Stryker; nonconsulting fees from Arthrex and Smith & Nephew; and royalties from ConforMIS; and has an ownership interest in ConforMIS. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2021.)

Background: Hip arthroscopy is associated with moderate to severe postoperative pain. This prospective, randomized, double-blinded study investigates the clinically analgesic effect of anterior quadratus lumborum block with multimodal analgesia compared to multimodal analgesia alone. The authors hypothesized that an anterior quadratus lumborum block with multimodal analgesia would be superior for pain control., Methods: Ninety-six adult patients undergoing ambulatory hip arthroscopy were enrolled. Patients were randomized to either a single-shot anterior quadratus lumborum block (30 ml bupivacaine 0.5% with 2 mg preservative-free dexamethasone) or no block. All patients received neuraxial anesthesia, IV sedation, and multimodal analgesia (IV acetaminophen and ketorolac). The primary outcome was numerical rating scale pain scores at rest and movement at 30 min and 1, 2, 3, and 24 h., Results: Ninety-six patients were enrolled and included in the analysis. Anterior quadratus lumborum block with multimodal analgesia (overall treatment effect, marginal mean [standard error]: 4.4 [0.3]) was not superior to multimodal analgesia alone (overall treatment effect, marginal mean [standard error]: 3.7 [0.3]) in pain scores over the study period (treatment differences between no block and anterior quadratus lumborum block, 0.7 [95% CI, -0.1 to 1.5]; P = 0.059). Postanesthesia care unit antiemetic use, patient satisfaction, and opioid consumption for 0 to 24 h were not significantly different. There was no difference in quadriceps strength on the operative side between groups (differences in means, 1.9 [95% CI, -1.5 to 5.3]; P = 0.268)., Conclusions: Anterior quadratus lumborum block may not add to the benefits provided by multimodal analgesia alone after hip arthroscopy. Anterior quadratus lumborum block did not cause a motor deficit. The lack of treatment effect in this study demonstrates a surgical procedure without benefit from this novel block., (Copyright © 2021, the American Society of Anesthesiologists. All Rights Reserved.)

There is a paucity of literature on patient-reported outcome measures (PROMs) following proximal hamstring repair beyond return to play, patient satisfaction and pain improvement. The minimal clinically important difference (MCID) defines the minimum degree of quantifiable improvement that a patient can perceive, but the MCID and predictors of this measure have not been defined for this patient population. This study aimed to define the MCID and determine the efficacy of open proximal hamstring repair through achievement of MCID and identify characteristics predictive of achieving MCID. A retrospective cohort review of an institutional hip registry was conducted, analyzing the modified Harris Hip Score (mHHS) and International Hip Outcome Tool (iHOT-33). MCID was calculated using a distribution-based method. Demographic and clinical variables predictive of achieving MCID were analyzed using univariable and multivariate logistic regression analyses. Thirty-nine patients who underwent open proximal hamstring repair were included. The mean patient age was 48.5 ± 12.4 years, with a mean follow-up of 37.1 ± 28 months. The MCID was determined for each PROM (mHHS-11.8; iHOT-33-12.6). A high percentage of patients achieved MCID for both PROMs (mHHS-85.7%; iHOT-33-91.4%). Univariate logistical regression demonstrated increased age ( P   = 0.163), increased body mass index (BMI; P   = 0.072), requirement for inpatient admission ( P   = 0.088) and pre-operative iHOT-33 ( P   = 0.104) trended towards clinically significant predictors of not achieving MCID. A high percentage of patients achieved MCID while age, BMI, inpatient admission and pre-operative iHOT-33 appear to influence the achievement of clinically significant outcome in patients undergoing open proximal hamstring repair., (© The Author(s) 2021. Published by Oxford University Press.)

Background: The number of patients requiring reoperation has increased as the volume of hip arthroscopy for femoroacetabular impingement syndrome (FAIS) has increased. The factors most important in determining patients who are likely to require reoperation remain elusive., Purpose: To leverage machine learning to better characterize the complex relationship across various preoperative factors (patient characteristics, radiographic parameters, patient-reported outcome measures [PROMs]) for patients undergoing primary hip arthroscopy for FAIS to determine which features predict the need for future ipsilateral hip reoperation, namely, revision hip arthroscopy, total hip arthroplasty (THA), hip resurfacing arthroplasty (HRA), or periacetabular osteotomy (PAO)., Study Design: Cohort study; Level of evidence, 3., Methods: A cohort of 3147 patients undergoing 3748 primary hip arthroscopy procedures were included from an institutional hip preservation registry. Preoperative computed tomography of the hip was obtained for each patient, from which the following parameters were calculated: the alpha angle; the coronal center-edge angle; the neck-shaft angle; the acetabular version angle at 1, 2, and 3 o'clock; and the femoral version angle. Preoperative PROMs included the modified Harris Hip Score (mHHS), the Hip Outcome Score (HOS)-Activities of Daily Living subscale (HOS-ADL) and the Sport Specific subscale, and the international Hip Outcome Tool (iHOT-33). Random forest models were created for revision hip arthroscopy, the THA, the HRA, and the PAO. Area under the curve (AUC) for the receiver operating characteristic curve and accuracy were calculated to evaluate each model., Results: A total of 171 patients (4.6%) underwent subsequent hip surgery after primary hip arthroscopy for FAIS. The AUC and accuracy, respectively, were 0.77 (fair) and 76% for revision hip arthroscopy (mean, 26.4-month follow-up); 0.80 (good) and 81% for THA (mean, 32.5-month follow-up); 0.62 (poor) and 69% for HRA (mean, 45.4-month follow-up); and 0.76 (fair) and 74% for PAO (mean, 30.4-month follow-up). The most important factors in predicting reoperation after primary hip arthroscopy were higher body mass index (BMI) and lower preoperative HOS-ADL for revision hip arthroscopy, greater age and lower preoperative iHOT-33 for THA, increased BMI for HRA, and larger neck-shaft angle and lower preoperative mHHS for PAO., Conclusion: Despite the low failure rate of hip arthroscopy for FAIS, our study demonstrated that machine learning has the capability to identify key preoperative risk factors that may predict subsequent ipsilateral hip surgery before the index hip arthroscopy. Knowledge of these demographic, radiographic, and patient-reported outcome data may aid in preoperative counseling and expectation management to better optimize hip preservation.

Background: Idiopathic Pulmonary Fibrosis is a chronic, progressive interstitial lung disease for which there is no cure. However, lung function decline, hospitalizations, and mortality may be reduced with the use of the antifibrotic medications, nintedanib and pirfenidone. Historical outcomes for hospitalized patients with Idiopathic Pulmonary Fibrosis are grim; however there is a paucity of data since the approval of nintedanib and pirfenidone for treatment. In this study, we aimed to determine the effect of nintedanib and pirfenidone on mortality following respiratory-related hospitalizations, intensive care unit (ICU) admission, and mechanical ventilation., Methods: Using a large U.S. insurance database, we created a one-to-one propensity score matched cohort of patients with idiopathic pulmonary fibrosis treated and untreated with an antifibrotic who underwent respiratory-related hospitalization between January 1, 2015 and December 31, 2018. Mortality was evaluated at 30 days and end of follow-up (up to 2 years). Subgroup analyses were performed for all patients receiving treatment in an ICU and those receiving invasive and non-invasive mechanical ventilation during the index hospitalization., Results: Antifibrotics were not observed to effect utilization of mechanical ventilation or ICU treatment during the index admission or effect mortality at 30-days. If patients survived hospitalization, mortality was reduced in the treated cohort compared to the untreated cohort when followed up to two years (20.1% vs 47.8%)., Conclusions: Treatment with antifibrotic medications does not appear to directly improve 30-day mortality during or after respiratory-related hospitalizations. Post-hospital discharge, however, ongoing antifibrotic treatment was associated with improved long-term survival., (© 2021. The Author(s).)