A Number of Modifiable and Nonmodifiable Factors Increase the Risk for Elbow Medial Ulnar Collateral Ligament Injury in Baseball Players: A Systematic Review.

PURPOSE: To analyze the current literature regarding risk factors associated with medial ulnar collateral ligament (MUCL) injury in baseball players and to serve as a robust source for identifying modifiable risk factors that once optimized, have the potential to reduce injury risk. METHODS: Comprehensive search of the available literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Studies were included if they evaluated risk factors for MUCL injuries in the elbow of baseball players. Risk of bias assessment was performed via Methodological Index for Non-randomized Studies (MINORS) scoring system. The Oxford Centre for Evidence-Based Medicine was used to determine level of evidence. Variables of interest; player age, position, shoulder motion, humeral retrotorsion, joint laxity, strength, balance, geography, velocity, pitch count, pitch types, throwing volumes, and throwing mechanics were recorded. RESULTS: Twenty-one studies were included in this systematic review. MINORS scores ranged from 75 to 87%, and variables demonstrated significant heterogeneity. Performance-based risk factors for MUCL injury included: increased pitch count (both annual and per game), higher percentage of fastballs thrown, smaller pitch repertoire, and/or a loss of pitching velocity. Biomechanical studies demonstrated the relationship between decreased shoulder range of motion (total ROM, ER, IR, and abduction), increased humeral retrotorsion, increased elbow valgus opening in the throwing arm, lower Y-Balance score, and increased lateral release position to increased MUCL injury. CONCLUSIONS: Risk factors for MUCL injury can generally be categorized into 4 primary groups: 1) various player demographics and characteristics, 2) throwing too hard (high velocity), 3) throwing too much (pitch count/volume), and 4) throwing with poor mechanics. In this systematic review, the most significant nonmodifiable risk factors for MUCL injuries included: increased glenohumeral retrotorsion and elbow valgus opening. The most consistent modifiable risk factors included: total shoulder range of motion, pitch count, pitch selection, Y balance score, and lateral release position. Pitch velocity was inconsistent in literature, but most studies found this as a risk for injury. These risk factors may serve as appropriate targets for future evidence-based injury mitigation strategies. LEVEL OF EVIDENCE: Level IV, systematic review of Level II-IV studies.

Nonoperative Management of Posterior Shoulder Instability: What Are the Long-Term Clinical Outcomes?

OBJECTIVE: To report the injury characteristics, radiographic findings, and long-term outcomes of nonoperative management for posterior shoulder instability (PSI). DESIGN: A retrospective review of 143 patients with PSI using a large geographic database. SETTING: Single county between January 1994 and July 2012. PATIENTS: A clinical history and diagnosis of PSI, one confirmatory imaging study to support the diagnosis, and a minimum of 5 years follow-up were required for inclusion. Patients with seizure disorders, anterior-only instability, multidirectional instability, and superior labrum from anterior to posterior diagnosis were excluded. INTERVENTIONS: Patients with PSI were managed nonoperatively or operatively. MAIN OUTCOME MEASURES: Pain, recurrent instability, and progression into glenohumeral osteoarthritis at long-term follow-up. RESULTS: One hundred fifteen patients were identified. Thirty-seven (32%) underwent nonoperative management. Twenty (54%) patients were diagnosed with posterior subluxation, 3 (8%) with a single dislocation, and 7 (19%) with multiple dislocations. Symptomatic progression of glenohumeral arthritis was observed in 8% (3) of patients. Pain improved in 46% (17) of patients and worsened in 19% (7). Recurrent instability and progression to osteoarthritis occurred in 15% (3/20) of patients with a traumatic instability event compared with 0% of atraumatic patients after nonoperative management (P = 0.234). Pain at follow-up was more common in nonoperative than operative patients (P = 0.017). CONCLUSIONS: Nonoperative management is a viable option for many patients with posterior shoulder instability; however, many may continue to have posterior shoulder pain.

Nonoperative management of anterior shoulder instability can result in high rates of recurrent instability and pain at long-term follow-up.

BACKGROUND: Data on the long-term outcomes of nonoperative treatment of anterior shoulder instability are lacking, particularly for the US population. The purpose was to (1) describe the characteristics of patients with anterior shoulder instability treated nonoperatively, (2) assess the long-term outcomes of nonoperative management in a US population, and (3) identify risk factors for poor outcomes following nonoperative management. METHODS: A geographic cohort of >500,000 subjects was used to identify patients treated nonoperatively for anterior shoulder instability. Only patients aged <40 years at the time of initial instability with minimum 10-year follow-up were included. Medical records were reviewed to obtain demographic characteristics, physical examination findings, clinical history data, imaging results, treatment details, and clinical and/or radiographic progression. Recurrent pain, recurrent instability, and the development of symptomatic osteoarthritis (OA) were the primary outcomes evaluated. RESULTS: The study included 254 patients (73% male) with a median age of 19 years (range, 16-26 years) at the time of initial instability. At median 17-year follow-up, 37.5% experienced recurrent instability, 58.4% had recurrent pain, and 12.2% had symptomatic OA development. Factors associated with recurrent pain at final follow-up were multiple instability events prior to presentation (hazard ratio [HR], 2.43; P < .01) and increased pain at the initial visit (HRs of 0.79 for mild, 1.74 for moderate, and 1.39 for severe; P < .01); patients with multiple instability events prior to presentation also had an increased risk of recurrence (P < .01). Factors increasing the risk of the development of symptomatic OA included increased pain at the initial visit (P = .05), seizure disorder (HR, 27.01; P < .01), and smoking (HR, 5.15; P < .01). CONCLUSIONS: At long-term follow-up of 17 years, a high rate of poor outcomes was observed following nonoperative management of anterior shoulder instability. Overall, 37.5% of patients experienced recurrent shoulder instability, 58.4% had recurrent shoulder pain, and 12.2% had symptomatic OA development. Risk factors associated with adverse clinical outcomes included increased pain at the initial visit, recurrent instability prior to presentation, seizure disorder, and smoking.

Hamstring Autograft Anterior Cruciate Ligament Reconstruction Using an All-Inside Technique With and Without Independent Suture Tape Reinforcement.

PURPOSE: To compare the (1) rates of complications and reoperations, (2) rate of anterior cruciate ligament (ACL) graft failure, and (3) patient-reported outcomes (PROs) among patients after hamstring autograft ACL reconstruction (ACLR) with and without independent suture tape reinforcement at a minimum 2-year clinical follow-up. METHODS: We performed a 1:2 matched-cohort comparison of patients who underwent hamstring autograft ACLR with and without independent suture tape reinforcement between July 2011 and July 2017. Patients were matched according to age, sex, body mass index, preinjury Tegner activity score, and concomitant meniscal injury. Medical records were reviewed for demographic characteristics, additional injuries, and concomitant procedures. PRO scores (including Tegner activity, Lysholm, and International Knee Documentation Committee scores) and physical examination findings were collected both preoperatively and at a minimum of 2 years postoperatively. RESULTS: Overall, 108 patients who underwent ACLR were included: 36 patients (mean age, 25.3 years; range, 13-44 years) with independent suture tape reinforcement and 72 patients (mean age, 24.9 years; range, 13-54 years) without suture tape reinforcement. Overall, 5 of 36 suture tape patients (14%) and 10 of 72 control patients (14%) underwent reoperations. At an average follow-up of 26.1 months in the suture tape cohort and 31.3 months in the control cohort, 1 patient in the suture tape cohort and 4 patients in the control cohort experienced graft failure. There were no statistically significant differences between the suture tape and control groups regarding return-to-sport rate (89% and 88%, respectively), postoperative International Knee Documentation Committee score (94.4 and 93.8, respectively), and postoperative Lysholm score (95.6 and 94, respectively). There was a statistically significant difference between the suture tape and control groups in postoperative Tegner activity score, at 7.1 (95% confidence interval, 6.5-7.6) and 6.4 (95% confidence interval, 6.2-6.6), respectively (P = .026). CONCLUSIONS: ACLR with hamstring autograft and independent suture tape reinforcement was performed safely with low rates of complications, graft failure, and reoperations with similar PROs, function, and return-to-sport rates when compared with hamstring autograft ACLR without suture tape reinforcement at a minimum 2-year follow-up. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Players' perspectives on successfully returning to professional baseball after medial ulnar collateral ligament reconstruction.

BACKGROUND: As the incidence of ulnar collateral ligament reconstruction (UCLR) surgery continues to rise, an improved understanding of baseball pitchers' perspectives on the postoperative recovery process and return to pitching is needed. The purpose of this study was to analyze pitchers' perspectives on recovery after UCLR. METHODS: dDuring the 2018 baseball season, an online questionnaire was distributed to the certified athletic trainers of all 30 Major League Baseball (MLB) organizations. These athletic trainers then administered the survey to all players within their organization including MLB and 6 levels of Minor League Baseball. MLB or Minor League Baseball pitchers who had previously undergone UCLR and participated in a rehabilitation program (or were currently participating in one at time of the survey) were included in the study. RESULTS: There were 530 professional pitchers who met inclusion criteria. The majority (81%) of pitchers began rehabilitation within 2 weeks of surgery, with 51% beginning within 1 week. The majority of pitchers began a long-toss throwing program at 5 and 6 months after surgery (27% and 21%), with 52% making their first throw off a mound between 7 and 9 months. The number of pitchers who participated in a weighted ball throwing program decreased significantly after surgery (20%-11%, P < .001). After UCLR, 56% of pitchers reported no changes regarding pitching mechanics or types of pitches thrown, 42% reported changed mechanics, and only 3% either decreased or stopped throwing a certain pitch type. Overall, 54% believed that their current throwing velocity was faster than their velocity before ulnar collateral ligament injury. Twenty percent of pitchers reported experiencing a setback that resulted in temporary stoppage of their rehabilitation program, the most common reason being flexor tightness or tendonitis (53%). Seventy-six percent reported that they were not concerned about sustaining another elbow injury; however, significantly less (61%; P < .001) stated that they would have UCLR again if necessary. CONCLUSIONS: Although UCLR is generally reported to have excellent clinical outcomes, 20% of pitchers experienced a significant setback during their rehabilitation and only 61% of pitchers, having gone through UCLR and the subsequent recovery, would be willing to undergo revision surgery and repeat the rehabilitation process if it were to become necessary. In addition, 42% of pitchers felt that they had to alter their throwing mechanics to return to pitching. Surgeons and athletic trainers should aim to understand the UCLR recovery process from the pitchers' perspective to better counsel future patients recovering from UCLR.

Capitellar Osteochondritis Dissecans Lesions of the Elbow: A Systematic Review of Osteochondral Graft Reconstruction Options.

PURPOSE: To systematically evaluate the outcomes and complications of osteochondral autograft transfer (OAT) and osteochondral allograft transplantation (OCA) for the surgical treatment of capitellar osteochondritis dissecans (OCD). METHODS: A literature search was conducted across 3 databases (PubMed, Cochrane, and CINAHL [Cumulative Index to Nursing and Allied Health Literature]) from database inception through December 2019 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Individual study quality was assessed using the Methodological Index for Non-randomized Studies scale. Studies were published between 2005 and 2019. RESULTS: Eighteen studies consisting of 446 elbow OCD lesions treated with OAT surgery were included. There was a single OCA study eligible for inclusion. Patient ages ranged from 10 to 45 years. Of the OAT studies, 4 used autologous costal grafts whereas the remainder used autografts from the knee. Outcome measures were heterogeneously reported. A significant improvement in Timmerman-Andrews scores from preoperatively to postoperatively was reported in 9 of 10 studies. Return-to-play rates to the preinjury level of competitive play ranged from 62% to 100% across 16 studies. Significant improvement in motion, most often extension, was noted in most studies. Reported complication, reoperation, and failure rates ranged from 0% to 11%, 0% to 26%, and 0% to 20%, respectively. When used, knee autografts resulted in low donor-site morbidity (Lysholm scores, 70-100). CONCLUSIONS: OAT surgery for large, unstable OCD lesions of the capitellum reliably produced good outcomes, few complications, and a high rate of return to competitive play. Complications are relatively uncommon, and donor-site morbidity is low. Less is known about the performance of OCA given the paucity of available literature. LEVEL OF EVIDENCE: Level IV, systematic review of Level II to IV studies.

Meniscus repairs in the adolescent population-safe and reliable outcomes: a systematic review.

PURPOSE: The purpose of this study was to determine the outcomes of meniscus repair in the adolescent population, including: (1) failure and reoperation rates, (2) clinical and functional results, and (3) activity-related outcomes including return to sport. METHODS: Two authors independently searched MEDLINE, Cochrane Central Register of Controlled Trials & Cochrane Library, and CINHAL databases for literature related to meniscus repair in an adolescent population according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. No meta-analysis was performed in this qualitative systematic review. RESULTS: Thirteen studies, including no Level I, one Level II, one Level III, and eleven Level IV studies yielded 466 patients with 503 meniscus repairs. All defined meniscal re-tear as a primary endpoint, with a reported failure rate ranging from 0 to 42% at a follow-up ranging from 22 to 211 months. There were a total of 93 failed repairs. IKDC scores were reported in four studies with a mean improvement ranging from 24 to 42 (P < 0.001). Mean post-operative Lysholm scores were reported in seven studies, ranging from 85 to 96. Additionally, four of those studies provided mean pre-operative Lysholm scores, ranging from 56 to 79, with statistically significant mean score improvements ranging from 17 to 31. Mean post-operative Tegner Activity scores were reported in nine studies, with mean values ranging from 6.2 to 8. CONCLUSION: This systematic review demonstrates that both subjective and clinical outcomes, including failure rate, Lysholm, IKDC, and Tegner activity scale scores, are good to excellent following meniscal repair in the adolescent population. Further investigations should aim to isolate tear type, location, surgical technique, concomitant procedures, and rehabilitation protocols to overall rate of failure and clinical and functional outcomes. LEVEL OF EVIDENCE: IV.

Isolated meniscus extrusion associated with meniscotibial ligament abnormality.

PURPOSE: The purpose of this study was to describe meniscus extrusion, present imaging characteristics, and provide clinical correlations for patients with isolated meniscus extrusion. METHODS: Of the 3244 MRI reports identified as having meniscus extrusion, 20 patients were identified to have isolated meniscus extrusion (0.62%). Patients with moderate to severe chondromalacia, meniscus tears, intra-articular fractures, tumours, and ligament tears were excluded. Radiographs were reviewed and graded using Kellgren-Lawrence (K-L) scores. MRI's were reviewed for the extent of extrusion and whether or not the meniscotibial ligament was intact. Clinical presentation and management were recorded. RESULTS: The study population consisted of 12 females and 8 males with a mean age of 40.5, diagnosed with meniscus extrusion and minimal concomitant knee pathology. 68% of patients were considered symptomatic as their knee pain correlated with the side of their meniscus extrusion and no other reason for pain was identified. The mean amount of meniscus extrusion was 2.5 mm (SD ± 1.1 mm) with 45% (9 of 20) having 3 + mm of extrusion. Meniscotibial ligament abnormality was identified in 65% of cases (13 of 20). Patients with 3 + mm of meniscus extrusion were much more likely to have associated meniscotibial ligament abnormality (100%, 9 of 9) compared to those with < 3 mm of extrusion (36%, 4 of 11) (RR 2.75, p = 0.048). The mean K-L grade obtained at the initial visit was 0.9 (95% CI 0.7-1.4) and the mean K-L grade obtained on final follow-up was 1.3 (95% CI 0.8-2.8) (n.s.) at a mean of 44.7 months. No correlation was found between K-L grade, gender, age, acute injury, and BMI in relation to meniscotibial ligament abnormality or amount of meniscal extrusion. CONCLUSIONS: Meniscus extrusion often occurs in the presence of significant knee pathology, predominantly with meniscus tears or osteoarthritis. Isolated meniscus extrusion is a rare occurrence that may present clinically with knee pain, commonly to the side in which the extrusion occurs. In patients with three or more millimetres of meniscus extrusion, an intact meniscus and minimal knee pathology, meniscotibial ligament abnormality is likely. This may provide an opportunity to treat the meniscotibial ligament abnormality with meniscus centralisation technique and decrease the amount of meniscus extrusion.

No difference between single and staged posterolateral corner surgical procedures in the multiligament injured/dislocated knee.

PURPOSE: Posterolateral corner (PLC) injuries commonly occur in the setting of a dislocated knee and often require multiple procedures due to concomitant vascular, nerve, and soft tissue involvement. Debate persists regarding single vs staged surgery. The purpose of this study was to compare knee function after single and staged surgery for PLC injury. METHODS: Patients who underwent surgery for a PLC injury (KD I, IIIL, IV) with minimum follow-up of 2 years were included. Patients treated with staged and single surgery were matched according to age, sex, and KD grade. Lysholm and International Knee Documentation Committee (IKDC) subjective scores were obtained. Risk factors for poor knee function were assessed, including age, nerve, vascular, meniscal and articular cartilage injuries. RESULTS: Twenty single-surgery patients with a median age of 24 years (median follow-up 5.3 years, range 2-18.3) and 20 staged surgery patients with a median age of 26 years (median follow-up 4.3 years, range 2-19.8) were studied. The mean Lysholm score was 78.7 (± 20.3) in the single surgery and 84.2 (± 17.8) in the staged surgery cohort (n.s.). The mean IKDC score was 80.8 (± 21.1) in the single and 74.9 (± 18.9) in the staged surgery cohort (n.s.). Age at injury, peroneal, vascular, meniscal or cartilage injury were not associated with poor knee outcome. CONCLUSION: This study demonstrates similar knee function among patients with PLC injuries treated with single or staged surgical procedures. The need for staged surgery for the dislocated knee with PLC involvement should be individualized based on specific knee and patient-related factors. LEVEL OF EVIDENCE: III.

Does Internal Fixation for Unstable Osteochondritis Dissecans of the Skeletally Mature Knee Work? A Systematic Review.

PURPOSE: To report the rate of radiographic union, patient-reported outcomes, complications, and reoperations after internal fixation of unstable osteochondritis dissecans (OCD) in the skeletally mature knee. METHODS: A literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Patients were included if they were skeletally mature and underwent internal fixation of an unstable OCD lesion of the knee. Risk of bias assessment was performed using the Methodological Index for Non-randomized Studies scoring system. Surgical technique, rate of union, patient-reported outcomes, complications, and reoperations were collected. RESULTS: Thirteen studies resulted in 148 patients (150 knees) for inclusion. Patient age ranged from 14 to 45 years. Numerous fixation procedures were used, including biodegradable devices (rods, pins, nails, and screws), metal screws, Kirschner wire, and autologous bone sticks. Overall, reported outcome measures were heterogeneous in nature. The rate of radiographic healing ranged from 67% to 100% across 6 studies. Improved subjective results and Hughston criteria on final follow-up ranged from 83% to 100% across 4 studies each. Mean postoperative Lysholm scores ranged from 42 to 98 in studies that reported them. Both complication and reoperation rates ranged from 0% to 44%. The most commonly performed reoperations were loose body excision and cartilage resurfacing procedures. CONCLUSIONS: A variety of surgical techniques are available for treatment of unstable OCD lesions in the skeletally mature knee. In this systematic review, internal fixation of the native fragment showed acceptable rates of radiographic union and improved patient-reported outcomes relative to other techniques. LEVEL OF EVIDENCE: Level IV, systematic review of level III-IV studies.

Sutures, Screws, Buttons, and Anchors: A Review of Current Bone Graft Fixation Devices for Glenoid Bone Loss in the Unstable Shoulder.

PURPOSE OF REVIEW: Anterior shoulder instability is associated with concomitant injury to several stabilizing structures of the shoulder, including glenoid bone loss. While instability is most common in young athletes and patients with predisposing conditions of hyperlaxity, recurrent shoulder instability can occur throughout various age ranges and may lead to longer term effects including pain and shoulder arthritis. Glenoid bone loss exceeding certain thresholds is generally treated by glenoid reconstruction via bone block augmentation to adequately stabilize the glenohumeral joint. These procedures increase the width of the articular surface on which the humeral head can translate before dislocation and, based on the procedure performed, provide a sling effect via the conjoined tendon, and increase tension to support the anterior capsule. The purpose of this review is to summarize the available literature regarding bone block fixation techniques. RECENT DEVELOPMENTS: Various fixation techniques have been utilized to secure bone block transfers. Though screw fixation has traditionally been used for bone block fixation, suture buttons, suture anchors, and all-suture techniques have been utilized in attempts to avoid complications associated with the use of screws. Biomechanical studies report variable force-resistance, displacement, and mode of failure when comparing screw to suture button-based fixation of glenoid bone blocks. Clinical and radiographic studies have shown these novel suture-based techniques to be comparable, and in some cases advantageous, to traditional screw fixation techniques. While screw fixation has long been the standard of care in glenoid bone block procedures, it is associated with high complication rates, leading surgeons to endeavor toward new fixation techniques. In available biomechanical studies, screw fixation has consistently demonstrated high maximal load-to-failure and displacement with cyclic loading. Studies have reported similar clinical and radiographic outcomes in both screw and suture-based fixation methods, with evidence of reduced bone resorption with suture fixation. While suture button fixation is associated with a higher rate of recurrent instability, overall complication rates are low. Future research should address biomechanical shortcomings of suture-based fixation techniques and continue to assess long-term follow-up of patients treated with each fixation method.

Factors that Increase Elbow Stress in the Throwing Athlete: a Systematic Review of Biomechanical and Motion Analysis Studies of Baseball Pitching and Throwing.

PURPOSE OF REVIEW: Elbow pain poses a unique challenge in the throwing athlete. Due to the high levels of elbow stress during the throwing motion, elbow injuries are common in throwers of all ages. There are several postulated factors believed to contribute increased stress to the throwing elbow. A detailed review of the published biomechanical studies evaluating the stresses experienced by the throwing elbow is needed. Here, we review these biomechanical studies to extrapolate the contributing factors that increase stress, the modifications that may reduce such stress, and the post-injury rehabilitation that optimizes outcomes and reduces recurrence. RECENT FINDINGS: The biomechanical forces on the elbow have been further investigated delineated in recent work. Rotational malalignment of the shoulder, including both GIRD and decreased adduction, increases torque experienced by the elbow during pitching motions. Exact interactions between lower extremity, lumbopelvic or trunk rotation, and elbow forces during throwing remain uncertain with mixed results in recent literature. Pitch types may influence elbow stresses although delivery mechanism and distance thrown do not. Several biomechanical factors influence the stresses imparted on the throwing elbow. Throwing volume, proper throwing mechanics, and appropriate rehabilitation are likely to be to be the most influential on mitigating unnecessary stresses imparted to the elbow in the throwing athlete. A proper understanding of these factors may reduce the occurrence of these injuries in this population. Moreover, an understanding of proper rehabilitation following injury may ensure optimized results and reduce recurrence.

Progression of Osteoarthritis at Long-term Follow-up in Patients Treated for Symptomatic Femoroacetabular Impingement With Hip Arthroscopy Compared With Nonsurgically Treated Patients.

BACKGROUND: Femoroacetabular impingement (FAI) is a common cause of hip pain, especially in young patients. When left untreated, it has been demonstrated to be a risk factor for the onset or progression of osteoarthritis (OA) and has been identified as one of the main contributors leading to the need for total hip arthroplasty (THA) at a young age. While the short-term therapeutic potential of hip arthroscopy is widely recognized, little is known regarding its potential mid- to long-term preventive effect on the progression of hip OA. PURPOSE: To (1) report clinical outcomes of arthroscopically treated FAI syndrome with a minimum 5-year follow-up and compare the results to a cohort with FAI treated nonsurgically and (2) determine the influence of hip arthroscopy on the onset and progression of hip OA in patients diagnosed with FAI. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients who had hip pain and were diagnosed with FAI were included. Exclusion criteria were (1) previous or concomitant hip surgery, (2) <5 years of follow-up, and (3) insufficient radiographs. Patients treated with hip arthroscopy were compared with a cohort of patients with FAI who were treated nonsurgically. Kaplan-Meier estimates of failure (defined as conversion to THA) were performed. Bivariate analysis and Cox regression were used to identify factors associated with inferior clinical and radiographic outcomes. RESULTS: A total of 957 patients (650 female, 307 male; 1114 hips) (mean age, 28.03 ± 8.9 years [range, 6.5-41.0 years]) with FAI were included. A total of 132 hips underwent hip arthroscopy and 982 hips were nonoperatively treated. The mean follow-up was 12.5 ± 4.7 years (range, 5.0-23.4 years). At the final follow-up, the rate of OA progression was 26.5% in the operative group and 35.2% in the nonoperative cohort (P < .01). Conversion to THA was performed in 6.8% of the surgical patients and 10.5% of the initially nonsurgical patients (P = .19). Additionally, there was no significant difference in the risk of failure between the operatively and nonoperatively treated patients. Male sex, increased age at initial diagnosis, presence of cam morphology, and increased initial Tönnis grade were risk factors for failure (male sex: hazard ratio [HR], 2.3; P < .01; per year of increased age: HR, 1.1; P < .01; presence of cam: HR, 3.5; P < .01; per Tönnis grade: HR, 4.0; P < .01). CONCLUSION: At a mean follow-up of nearly 13 years, 7% of patients of the surgical group experienced progression to THA, compared with 11% of the nonoperative control group. While most of the operative group showed little to no OA at final follow-up, moderate OA (Tönnis grade 2) was present in 12% of the cohort compared with 22% of nonsurgical patients. Increased age at diagnosis, male sex, presence of a cam morphology, and presence of initial arthritic joint changes were found to be risk factors for failure. The results of this study demonstrated evidence for a preventive effect of hip arthroscopy on the development and progression of OA in young patients with FAI at mid- to long-term follow-up.

Neurological Complications Following Arthroscopic and Related Sports Surgery: Prevention, Work-up, and Treatment.

Arthroscopy of the shoulder, elbow, hip, and knee has become increasingly utilized due to continued advancements in technique, training, and instrumentation. In addition, arthroscopy is generally safe and effective in the utilization of joint preservation surgical techniques. The arthroscopist must utilize a thorough understanding of the surgical anatomy, detailed care with patient positioning, and safe instrumentation portals to prevent associated neurological injury. In the event of postoperative neurological complications, the physician must carefully document the patient history and physical examination while considering the utilization of additional imaging, testing, or surgical nerve exploration with a specialized team depending upon the severity of neurological injury. In this review, we discuss the prevention, evaluation, and treatment of neurological complications related for arthroscopic procedures of the shoulder, elbow, hip, and knee.

Articular Cartilage Defects of the Glenohumeral Joint: A Systematic Review of Treatment Options and Outcomes.

OBJECTIVE: To report radiographic and magnetic resonance imaging findings, patient-reported outcomes, and complications and/or reoperations following nonarthroplasty surgical intervention for focal glenohumeral cartilage defects. DESIGN: A literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Patients were included if they possessed a chondral defect of the humeral head, glenoid, or both, which had been treated with a joint preserving nonarthroplasty procedure. Risk of bias assessment was performed using the Methodological Index for Non-Randomized Studies scoring system. Study demographics, surgical technique, imaging findings, patient-reported outcomes, complications, failures, and reoperations were collected. RESULTS: Fourteen studies with 98 patients (100 shoulders) met the inclusion criteria. Patient ages ranged from 7 to 74 years. The nonarthroplasty surgical techniques utilized included microfracture (67 shoulders), osteochondral transplantation (28 shoulders), chondrocyte transplantation (4 shoulders), and internal fixation (1 shoulder). The rates of radiographic union and progression of osteoarthritis ranged between 90% to 100% and 57% to 100%, respectively. Visual analog scores ranged from 0 to 1.9 at final follow-up. Mean postoperative ASES (American Shoulder and Elbow Surgeons) shoulder scores ranged from 75.8-100. Mean postoperative CSS (Constant Shoulder Score) scores ranged from 83.3-94. Mean postoperative SSV (Subjective Shoulder Value) ranged from 70% to 99%. Failure and reoperation rates ranged between 0% to 35% and 0% to 30%, respectively, with the most common reoperation being conversion to prosthetic arthroplasty. CONCLUSIONS: In this systematic review, nonarthroplasty surgical techniques demonstrated acceptable rates of radiographic healing, improved patient reported outcomes, minimal complications, and low rates of failure or reoperation. Joint preserving techniques are likely viable options to prolong function of the native shoulder and provide short- to midterm pain relief in young and highly active patients. LEVEL OF EVIDENCE: Level IV.

Understanding Anterior Shoulder Instability Through Machine Learning: New Models That Predict Recurrence, Progression to Surgery, and Development of Arthritis.

BACKGROUND: Management of anterior shoulder instability (ASI) aims to reduce risk of future recurrence and prevent complications via nonoperative and surgical management. Machine learning may be able to reliably provide predictions to improve decision making for this condition. PURPOSE: To develop and internally validate a machine-learning model to predict the following outcomes after ASI: (1) recurrent instability, (2) progression to surgery, and (3) the development of symptomatic osteoarthritis (OA) over long-term follow-up. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 2. METHODS: An established geographic database of >500,000 patients was used to identify 654 patients aged <40 years with an initial diagnosis of ASI between 1994 and 2016; the mean follow-up was 11.1 years. Medical records were reviewed to obtain patient information, and models were generated to predict the outcomes of interest. Five candidate algorithms were trained in the development of each of the models, as well as an additional ensemble of the algorithms. Performance of the algorithms was assessed using discrimination, calibration, and decision curve analysis. RESULTS: Of the 654 included patients, 443 (67.7%) experienced multiple instability events, 228 (34.9%) underwent surgery, and 39 (5.9%) developed symptomatic OA. The ensemble gradient-boosted machines achieved the best performances based on discrimination (via area under the receiver operating characteristic curve [AUC]: AUCrecurrence = 0.86), AUCsurgery = 0.76, AUCOA = 0.78), calibration, decision curve analysis, and Brier score (Brierrecurrence = 0.138, Briersurgery = 0.185, BrierOA = 0.05). For demonstration purposes, models were integrated into a single web-based open-access application able to provide predictions and explanations for practitioners and researchers. CONCLUSION: After identification of key features, including time from initial instability, age at initial instability, sports involvement, and radiographic findings, machine-learning models were developed that effectively and reliably predicted recurrent instability, progression to surgery, and the development of OA in patients with ASI. After careful external validation, these models can be incorporated into open-access digital applications to inform patients, clinicians, and researchers regarding quantifiable risks of relevant outcomes in the clinic.

Both Debridement and Microfracture Produce Excellent Results for Osteochondritis Dissecans Lesions of the Capitellum: A Systematic Review.

PURPOSE: To analyze the available literature pertaining to the indications, outcomes, and complications of both microfracture (MFX) and simple debridement for capitellar osteochondritis dissecans (OCD). METHODS: A comprehensive literature review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria. Studies were included if they evaluated OCD of the capitellum that underwent either arthroscopic debridement (AD) or MFX. The risk of bias was assessed using the Methodological Index for Non-randomized Studies (MINORS) scale. Patient demographic characteristics, imaging findings, return-to-sport rates, patient-reported outcomes, range of motion (ROM), complications, failures, and reoperations were recorded. RESULTS: Eleven studies with 327 patients (332 elbows) met the inclusion criteria. Methodological Index for Non-randomized Studies (MINORS) scores ranged from 63% to 75% and showed considerable heterogeneity. Both AD and MFX showed improvement in patient outcome scores, ROM, and return to play, although the data precluded relative conclusions. Improvement in motion after MFX ranged from 4.9° to 5° of flexion, 5° to 22.6° of extension, 1° to 2° of pronation, and 0.5° to 2° of supination, whereas after AD, it ranged from -4° to 6° of flexion and -0.4° to 14° of extension, with prono-supination noted in only 1 study. The rate of return to play at a similar level of preinjury athletic competition ranged from 55% to 75% after MFX and from 40% to 100% after AD. Lesion location was discussed in only 1 study. Postoperative imaging trended toward early degenerative changes, most commonly of the radial head. Complications were only reported in 1 MFX study; in all cases, the complication was transient ulnar nerve neurapraxia. Reoperation rates ranged from 0% to 10%, and reoperation was most commonly performed to address radial head enlargement. Five studies reported no reoperations. CONCLUSIONS: Both AD and MFX for capitellar OCD appear to yield excellent improvements in pain, ROM, patient outcome scores, and return to sport. Given that comparable mid-term outcomes can be achieved with debridement alone, without the use of MFX, similarly to recent prospective studies in the knee, AD alone may be a reasonable approach to relatively small OCD defects. LEVEL OF EVIDENCE: Level IV, systematic review of studies, all Level IV evidence.

Although Surgical Techniques Differ, Similar Outcomes Can Be Obtained When Operating After Single Versus Multiple Anterior Shoulder Dislocations.

PURPOSE: To compare the differences in preoperative pathology, surgical technique, and overall outcomes between patients treated surgically after a single anterior glenohumeral joint dislocation and those undergoing surgery after multiple dislocations. METHODS: An epidemiologic database was used to identify all patients younger than 40 years undergoing surgery for anterior shoulder instability between January 1, 1994, and July 31, 2016, in a defined geographic area. Patient medical records were reviewed to obtain demographic information, patient history, physical examination findings, imaging findings, clinical progression, surgical details, and outcomes. Comparative analysis was performed between patients who underwent surgery after a single dislocation and those who underwent surgery after multiple preoperative dislocations. RESULTS: The study population consisted of 187 patients who had a single anterior shoulder dislocation (n = 55) or multiple anterior shoulder dislocations (n = 132) prior to surgery. The mean follow-up period was 103.3 months (range, 0.3-328.4 months). Demographic characteristics were not significantly different between groups. Although the presence of Hill-Sachs lesions on radiographs was more common in the multiple-dislocation group (42.1%) than in the single-dislocation group (18.8%, P = .005), there were no other significant differences in concomitant pathology between groups. Latarjet procedures were more commonly performed in the multiple-dislocation group (12.5% vs 2.1% in the single-dislocation group, P = .04). There were no other significant differences in surgical techniques and characteristics between groups. Rates of survival free from recurrent instability (P = .790), revision surgery (P = .726), and progression to symptomatic osteoarthritis (P = .588) were not significantly different between groups. CONCLUSIONS: Although patients with multiple dislocations prior to surgery were more likely to show radiographic evidence of Hill-Sachs lesions and undergo the Latarjet procedure than those who received surgery after a single dislocation, no significant differences in outcomes with respect to recurrent instability, revision surgery, or progression to symptomatic osteoarthritis were found between these 2 groups at long-term follow-up. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Incidence of Hip Dysplasia Diagnosis in Young Patients With Hip Pain: A Geographic Population Cohort Analysis.

BACKGROUND: Hip dysplasia is a common source of hip pain and a known cause of early osteoarthritis of the hip. PURPOSE: To (1) define the population-based incidence of hip dysplasia diagnosis in young patients presenting with hip pain in a large geographically defined cohort, (2) analyze trends regarding presentation and diagnosis of hip dysplasia, and (3) report the rate and type of surgical interventions used to treat this population. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A geographic epidemiological database was queried to identify patients aged 14 to 50 years with hip pain between the years 2000 and 2016. Patient medical records were analyzed, and demographic, imaging, clinical, and treatment history were recorded. Incidence trends were examined by use of linear regression with confidence intervals for age and calendar year. RESULTS: Overall, 1893 patients were included. Of these, 156 patients (196 hips) had a diagnosis of hip dysplasia. The incidence of hip dysplasia diagnosis in patients who reported hip pain was 12.7 per 100,000 person-years. Patients with dysplasia had a mean age of 26.7 ± 9.8 years, while the highest age-adjusted incidence occurred at age 14 to 18 years in both male and female patients. Female patients had double the age-adjusted incidence of male patients (cases per 100,000 person-years: 16.8 [95% CI, 13.9-19.7] vs 8.7 [95% CI, 6.6-10.8]; P < .01). Of the patients who underwent magnetic resonance imaging, 77% had imaging consistent with labral pathology. Patients were treated with physical therapy (67%), intra-articular steroid injection (29%), hip arthroscopy (10%), and periacetabular osteotomy (9%). The use of hip arthroscopy significantly increased over time (P < .01), whereas the use of steroid injection and periacetabular osteotomy did not (P < .28 and P < .08, respectively). CONCLUSION: The incidence of hip dysplasia diagnosis in patients presenting with hip pain was 12.7 per 100,000 person-years. Female patients had twice the age-adjusted incidence of male patients, and the highest age-adjusted incidence occurred in the age range of 14 to 18 years in both sexes. The use of hip arthroscopy to treat patients with hip dysplasia significantly increased over time.

Risk of Conversion to Arthroplasty After Hip Arthroscopy: Validation of a Published Risk Score Using an Independent, Prospectively Collected Database.

BACKGROUND: Hip arthroscopy is rapidly advancing and increasingly commonly performed. The most common surgery after arthroscopy is total hip arthroplasty (THA), which unfortunately occurs within 2 years of arthroscopy in up to 10% of patients. Predictive models for conversion to THA, such as that proposed by Redmond et al, have potentially substantial value in perioperative counseling and decreasing early arthroscopy failures; however, these models need to be externally validated to demonstrate broad applicability. PURPOSE: To utilize an independent, prospectively collected database to externally validate a previously published risk calculator by determining its accuracy in predicting conversion of hip arthroscopy to THA at a minimum 2-year follow-up. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 1. METHODS: Hip arthroscopies performed at a single center between November 2015 and March 2017 were reviewed. Patients were assessed pre- and intraoperatively for components of the THA risk score studied-namely, age, modified Harris Hip Score, lateral center-edge angle, revision procedure, femoral version, and femoral and acetabular Outerbridge scores-and followed for a minimum of 2 years. Conversion to THA was determined along with the risk score's receiver operating characteristic (ROC) curve and Brier score calibration characteristics. RESULTS: A total of 187 patients (43 men, 144 women, mean age, 36.0 ± 12.4 years) underwent hip arthroscopy and were followed for a mean of 2.9 ± 0.85 years (range, 2.0-5.5 years), with 13 patients (7%) converting to THA at a mean of 1.6 ± 0.9 years. Patients who converted to THA had a mean predicted arthroplasty risk of 22.6% ± 12.0%, compared with patients who remained arthroplasty-free with a predicted risk of 4.6% ± 5.3% (P < .01). The Brier score for the calculator was 0.04 (P = .53), which was not statistically different from ideal calibration, and the calculator demonstrated a satisfactory area under the curve of 0.894 (P < .001). CONCLUSION: This external validation study supported our hypothesis in that the THA risk score described by Redmond et al was found to accurately predict which patients undergoing hip arthroscopy were at risk for converting to subsequent arthroplasty, with satisfactory discriminatory, ROC curve, and Brier score calibration characteristics. These findings are important in that they provide surgeons with validated tools to identify the patients at greatest risk for failure after hip arthroscopy and assist in perioperative counseling and decision making.