Anterior Shoulder Instability in Throwers and Overhead Athletes: Long-term Outcomes in a Geographic Cohort

Current Concepts on the Management of Shoulder Instability in Throwing Athletes

PURPOSE OF REVIEW

The management of shoulder instability in throwing athletes remains a challenge given the delicate balance between physiologic shoulder laxity facilitating performance and the inherent need for shoulder stability. This review will discuss the evaluation and management of a throwing athlete with suspected instability with a focus on recent findings and developments.

RECENT FINDINGS

The vast majority of throwing athletes with shoulder instability experience subtle microinstability as a result of repetitive microtrauma rather than episodes of gross instability. These athletes may present with arm pain, dead arms or reduced throwing velocity. Recent literature reinforces the fact that there is no "silver bullet" for the management of these athletes and an individualized, tailored approach to treatment is required. While initial nonoperative management remains the hallmark for treatment, the results of rehabilitation protocols are mixed, and some patients will ultimately undergo surgical stabilization. In these cases, it is imperative that the surgeon be judicious with the extent of surgical stabilization as overtightening of the glenohumeral joint is possible, which can adversely affect athlete performance. Managing shoulder instability in throwing athletes requires a thorough understanding of its physiologic and biomechanical underpinnings. Inconsistent results seen with surgical stabilization has led to a focus on nonoperative management for these athletes with surgery reserved for cases that fail to improve non-surgically. Overall, more high quality studies into the management of this challenging condition are warranted.

Overhead athletes have comparable intraoperative injury patterns and clinical outcomes to non-overhead athletes following surgical stabilization for first-time anterior shoulder instability at average 6-year follow-up

BACKGROUND AND HYPOTHESIS

Anterior shoulder instability is a common problem affecting young, athletic populations that results in potential career-altering functional limitations. However, little is known regarding the differences in clinical outcomes after operative management of overhead vs. non-overhead athletes presenting with first-time anterior shoulder instability. We hypothesized that overhead athletes would have milder clinical presentations, similar surgical characteristics, and diminished postoperative outcomes when compared with non-overhead athletes after surgical stabilization following first-time anterior shoulder instability episodes.

METHODS

Patients with first-time anterior shoulder instability events (subluxations and dislocations) undergoing operative management between 2013 and 2020 were included. The exclusion criteria included multiple dislocations and multidirectional shoulder instability. Baseline demographic characteristics, imaging data, examination findings, and intraoperative findings were retrospectively collected. Patients were contacted to collect postoperative patient-reported outcomes including American Shoulder and Elbow Surgeons score, Western Ontario Shoulder Instability Index score, Brophy activity index score, and Subjective Shoulder Value, in addition to return-to-work and -sport, recurrent dislocation, and revision rates.

RESULTS

A total of 256 patients met the inclusion criteria, of whom 178 (70%) were non-overhead athletes. The mean age of the entire population was 23.1 years. There was no significant difference in concomitant shoulder pathology, preoperative range of motion, or preoperative strength between cohorts. A greater proportion of overhead athletes presented with instability events not requiring manual reduction (defined as subluxations; 64.1% vs. 50.6%; P < .001) and underwent arthroscopic surgery (97% vs. 76%, P < .001) compared with non-overhead athletes. A smaller proportion of overhead athletes underwent open soft-tissue stabilization compared with non-overhead athletes (1% vs. 19%, P < .001). Outcome data were available for 60 patients with an average follow-up period of 6.7 years. No significant differences were found between groups with respect to recurrent postoperative instability event rate (13.0% for overhead athletes vs. 16.8% for non-overhead athletes), revision rate (13.0% for overhead athletes vs. 11.1% for non-overhead athletes), American Shoulder and Elbow Surgeons score, Western Ontario Shoulder Instability Index score, Brophy score, Subjective Shoulder Value, or rates of return to work or sport.

CONCLUSION

Overhead athletes who underwent surgery after an initial instability event were more likely to present with subluxations compared with non-overhead athletes. With limited follow-up subject to biases, this study found no differences in recurrence or revision rates, postoperative patient-reported outcomes, or return-to-work or -sport rates between overhead and non-overhead athletes undergoing shoulder stabilization surgery following first-time instability events. Although larger prospective studies are necessary to draw firmer conclusions, the findings of this study suggest that overhead athletes can be considered in the same treatment pathway for first-time dislocation as non-overhead athletes.

Outcomes of Shoulder Instability Surgery in Competitive Wrestlers: Outcomes, Reoperations, and Return to Play at 5 Years' Mean Follow-up

BACKGROUND

Wrestling is a physically demanding sport with young athletes prone to traumatic shoulder instability and a paucity of data evaluating the results of shoulder instability surgery (SIS).

PURPOSE

To assess reoperation rates, patient-reported outcomes, and return to wrestling (RTW) after SIS in a cohort of competitive wrestlers.

STUDY DESIGN

Case series; Level of evidence, 3.

METHODS

All competitive wrestlers with a history of shoulder instability and subsequent surgery at a single institution between 1996 and 2020 were identified. All directions of shoulder instability (anterior shoulder instability [ASI], posterior shoulder instability [PSI], and traumatic multidirectional shoulder instability [TMDI]) were analyzed. Exclusions included revision SIS and <2 years of follow-up. Athletes were contacted for determination of complications, RTW, and Western Ontario Shoulder Instability Index scores.

RESULTS

Ultimately, 104 wrestlers were included with a mean age at initial instability of 16.9 years (range, 12.0-22.7 years), mean age at surgery of 18.9 years (range, 14.0-29.0 years), and a mean follow-up of 5.2 years (range, 2.0-22.0 years). A total of 58 (55.8%) wrestlers were evaluated after a single shoulder instability event, while 46 (44.2%) sustained multiple events before evaluation. ASI was the most common direction (n = 79; 76.0%), followed by PSI (n = 14; 13.5%) and TMDI (n = 11; 10.6%). Surgical treatment was most commonly an arthroscopic soft tissue stabilization (n = 88; 84.6%), with open soft tissue repair (n = 13; 12.5%) and open bony augmentation (n = 3; 2.9%) performed less frequently. RTW occurred in 57.3% of wrestlers at a mean of 9.8 months. Recurrent instability was the most common complication, occurring in 18 (17.3%) wrestlers. Revision SIS was performed in 15 (14.4%) wrestlers. Across the entire cohort, survivorship rates free from recurrent instability and revision surgery were 90.4% and 92.5% at 2 years, 71.9% and 70.7% at 5 years, and 71.9% and 66.5% at 10 years, respectively. Preoperative recurrent instability was an independent risk factor for postoperative recurrent instability (hazard ratio, 3.8; 95% CI, 1.33-11.03; P = .012).

CONCLUSION

Competitive wrestlers with multiple dislocations before initial clinical evaluation were 3.8 times more likely to experience postoperative recurrent instability. Patients should be counseled that despite SIS, only 57.3% returned to wrestling after surgery.

Psychological Factors That Affect Return to Sport After Surgical Intervention for Shoulder Instability: A Systematic Review

Background

Recent advances have begun to identify the nonphysical factors facilitating successful return to sport (RTS) after shoulder instability surgery, yet little is currently known regarding psychological factors and RTS.

Purpose/Hypothesis

The purposes of this study were to (1) identify psychological factors associated with RTS, (2) evaluate the prognostic utility of various psychological factors, and (3) evaluate the available metrics used to assess psychological RTS readiness. It was hypothesized that psychological factors would be identified as critical elements influencing a patient's RTS.

Study Design

Systematic review; Level of evidence, 4.

Methods

Clinical studies reporting on the psychological determinants of RTS for patients who had surgery for shoulder instability between 1996 and 2022 were identified from MEDLINE, Embase, and Cochrane databases. Demographic, clinical, and psychometric properties were extracted for pooled weighted analysis.

Results

Of the 969 studies screened, 24 (2.5%) met inclusion criteria. Overall, 2135 patients were included (mean age, 26.0 years; range, 17.4-35.5 years; 84.7% male). The mean time to RTS was 6.8 months (range, 3.7-11.9 months). There was a 76.3% rate of any RTS; of the 1212 patients who reported level of play at return, 305 (25.2%) were unable to perform at their prior level. Psychological reasons were cited by 85% (n = 360) of patients who did not RTS. Fear of reinjury was the most common reason (n = 154; 42.8%); other psychological factors included lack of confidence (n = 46; 12.8%), anxiety (n = 45; 12.5%), depression (n = 44; 12.2%), psychosocial factors (n = 48; 13.3%), and lack of motivation (n = 23; 6.4%). The Shoulder Instability Return to Sport after Injury, Western Ontario Shoulder Instability Index, Quick Inventory of Depressive Symptoms Self Report, Degree of Shoulder Involvement in Sports, Tampa Scale of Kinesiophobia-11, and Veterans Rand 12-Item Health Survey were reported measures for assessing psychology and RTS.

Conclusion

Fear of reinjury was found to be the most commonly reported impediment to RTS. The psychological characteristics identified through this review may be incorporated into future RTS protocols seeking to address resilience and nonphysical factors associated with RTS.

Mid- to Long-Term Outcomes of Arthroscopic Shoulder Stabilization in Athletes: A Systematic Review

There exists a considerable amount of evidence regarding short-term outcomes of shoulder arthroscopy in athletes; however, mid- to long-term data are limited. Therefore, the purpose of this review is to evaluate studies assessing mid- to long-term outcomes and rates of return to sport in athletes undergoing primary shoulder arthroscopy. A search for the systematic review was performed in PubMed, Scopus, and Embase on 14 March 2023. Study parameters, as well as their respective outcomes, were described in detail and compiled into diagrams. Five studies were included, which contained data on a total of 307 shoulders in patients with mean ages ranging from 20.3 to 26.9 years and mean follow-up times ranging from 6.3 to 14 years. The arthroscopic Bankart repair was the primary surgical intervention performed in all five studies. The overall rate of return to sport was 84% (range, 70-100%) across the studies. The rate of return to sport at pre-injury level was 65.2% (range, 40-82.6%) across four studies. The overall rate of recurrent instability was 17.3%, with redislocation specifically occurring in 13.7% of patients across all studies. The overall rate of revision surgery was 11.1%. Athletes who underwent primary shoulder arthroscopy demonstrated favorable outcomes and a high rate of RTS at a minimum follow-up of 5 years. However, rates of recurrent instability, redislocation, and revision surgery occurred at less than favorable numbers, which emphasizes the importance of proper patient selection when considering candidates for arthroscopic versus open repairs.

Artificial Intelligence Can Define and Predict the "Optimal Observed Outcome" After Anterior Shoulder Instability Surgery: An Analysis of 200 Patients With 11-Year Mean Follow-Up

Purpose

The purpose of this study was to use unsupervised machine learning clustering to define the "optimal observed outcome" after surgery for anterior shoulder instability (ASI) and to identify predictors for achieving it.

Methods

Medical records, images, and operative reports were reviewed for patients <40 years old undergoing surgery for ASI. Four unsupervised machine learning clustering algorithms partitioned subjects into "optimal observed outcome" or "suboptimal outcome" based on combinations of actually observed outcomes. Demographic, clinical, and treatment variables were compared between groups using descriptive statistics and Kaplan-Meier survival curves. Variables were assessed for prognostic value through multivariate stepwise logistic regression.

Results

Two hundred patients with a mean follow-up of 11 years were included. Of these, 146 (64%) obtained the "optimal observed outcome," characterized by decreased: postoperative pain (23% vs 52%; P < 0.001), recurrent instability (12% vs 41%; P < 0.001), revision surgery (10% vs 24%; P = 0.015), osteoarthritis (OA) (5% vs 19%; P = 0.005), and restricted motion (161° vs 168°; P = 0.001). Forty-one percent of patients had a "perfect outcome," defined as ideal performance across all outcomes. Time from initial instability to presentation (odds ratio [OR] = 0.96; 95% confidence interval [CI], 0.92-0.98; P = 0.006) and habitual/voluntary instability (OR = 0.17; 95% CI, 0.04-0.77; P = 0.020) were negative predictors of achieving the "optimal observed outcome." A predilection toward subluxations rather than dislocations before surgery (OR = 1.30; 95% CI, 1.02-1.65; P = 0.030) was a positive predictor. Type of surgery performed was not a significant predictor.

Conclusion

After surgery for ASI, 64% of patients achieved the "optimal observed outcome" defined as minimal postoperative pain, no recurrent instability or OA, low revision surgery rates, and increased range of motion, of whom only 41% achieved a "perfect outcome." Positive predictors were shorter time to presentation and predilection toward preoperative subluxations over dislocations.

Level of Evidence

Retrospective cohort, level IV.

Diagnosis, prevention and treatment of common shoulder injuries in sport: grading the evidence - a statement paper commissioned by the Danish Society of Sports Physical Therapy (DSSF)

This statement paper summarises and appraises the evidence on diagnosis, prevention, and treatment of common shoulder injuries in sports. We systematically searched Medline and Embase. The Grading of Recommendations Assessment, Development and Evaluation tool was applied to evaluate the overall quality of evidence.For diagnosis, we included 19 clinical tests from mixed populations. Tests for anterior instability, biceps-labrum complex injuries and full subscapularis rupture had high diagnostic accuracy (low to moderate quality of evidence).For prevention, the Oslo Sports Trauma Research Center, the Shoulder Control, the FIFA 11+ shoulder injury prevention programmes, and a baseball-specific programme (range of motion, stretching, dynamic stability and strengthening exercises) showed moderate to large effect size in reducing the risk of shoulder injury compared with no intervention (very low to moderate quality of evidence).For treatment, a rehabilitation programme including stretching, ice packs, electrotherapy and compression, and strengthening exercises showed a large effect size in reducing pain and disability compared with no intervention in athletes with subacromial impingement syndrome (very low to moderate quality of evidence). For the treatment of supraspinatus tendinopathy, hyperthermia treatment (heating the skin to 38°C-40°C) resulted in large effect size in reducing pain and disability compared with ultrasound or pendular swinging and stretching exercises (moderate quality of evidence). Strengthening exercise alone or in combination with stretching exercises promoted a large effect in reducing shoulder pain (cohort studies, no comparators) (very low quality of evidence). The quality of evidence for most estimates was low to moderate, indicating that future high-quality research may alter our recommendations for clinical practice.

Clinical and Radiological Outcomes in Patients With Anterior Shoulder Instability and Glenoid Bone Loss after Arthroscopic Free Bone Block Combined With Dynamic Anterior Stabilization

BACKGROUND

As an alternative to the Latarjet procedure, the arthroscopic free bone block (FBB) procedure combined with dynamic anterior stabilization (DAS) has been recently proposed to provide both glenoid augmentation and a tendon sling effect for treating anterior shoulder instability (ASI) with glenoid bone loss.

PURPOSE

To evaluate the clinical and radiological outcomes of FBB-DAS for ASI with glenoid bone loss.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients who underwent arthroscopic FBB-DAS for ASI with >15% glenoid bone loss between February 2017 and March 2020 were screened and enrolled in this study. Clinical outcome measures were assessed preoperatively and at a minimum 2-year follow-up, including recurrence, complications, shoulder functional scores, range of motion, and return to sports. Postoperative computed tomography and magnetic resonance imaging were also performed.

RESULTS

Of a total of 65 patients with a mean follow-up of 46.1 ± 13.1 months, no patients experienced a recurrent dislocation or subluxation postoperatively, while 2 had a positive anterior apprehension test (3.1%). Additionally, 2 patients (3.1%) experienced complications of hematoma and shoulder stiffness, respectively. The mean visual analog scale score, American Shoulder and Elbow Surgeons score, Rowe score, and Oxford Shoulder Instability Score all improved significantly from 3.2 ± 2.4, 75.0 ± 18.9, 43.6 ± 27.3, and 33.8 ± 9.0 preoperatively to 1.3 ± 0.8, 95.1 ± 8.0, 95.5 ± 7.8, and 14.8 ± 3.5 at final follow-up, respectively (all P < .001). No difference was detected in range of motion except for 8.1° and 7.5° external rotation limitations in adduction and abduction, respectively. There were 62 patients (95.4%) who returned to sports, and 54 patients (83.1%) returned to the preinjury level. The transferred biceps tendon was intact in all 59 patients who completed radiological examination at the latest follow-up. Good bone healing was achieved in 98.3% of patients, and the glenoid bone defect decreased from 18.1% to 4.9%. Osseous and labral glenoids were significantly enlarged in width and depth on the latest magnetic resonance imaging (all P < .001).

CONCLUSION

Arthroscopic FBB-DAS provided satisfactory clinical and radiological outcomes for ASI with glenoid bone loss. Despite slight external rotation restrictions, it achieved low recurrence and complication rates, excellent shoulder functional scores, a high return-to-sports rate, and favorable graft healing and remodeling.

Managing Shoulder Instability in the Overhead Athlete

PURPOSE OF REVIEW

Shoulder instability in the overhead athlete is a difficult problem because of the balance between necessary laxity for athletic movements and stability of the joint. The purpose of this review is to provide an overview of the clinical evaluation of shoulder instability in the overhead athlete and present evidence-based management strategies for each subtype of shoulder instability, including novel techniques and outcomes.

RECENT FINDINGS

Recent investigation has shown that throwers and other overhead athletes are more likely to present with subtle subluxation events rather than discrete dislocations as their primary symptom. While overhead athletes with discrete anterior dislocation events are likely to begin with non-operative management, many progress on to surgical intervention. Surgical management of glenohumeral joint instability continues to pose challenges due to the potential for over-tensioning for the sake of stability at the expense of the adaptive laxity that often confers performance benefits in the overhead athlete. Novel, individualized, and sport/position specific approaches are needed to address this complex issue. The optimal management of shoulder instability in the overhead athlete continues to be a controversial topic due to the complex work-up, an increasing number of surgical options with varying indications, and low volume of high-quality studies comparing any of the treatment options. The Anterior Shoulder Instability International Consensus Group guidelines from February 2022 offer the most updated guidelines on work-up and management. Overall, high-quality randomized controlled trials are required to determine the optimal treatment for specific pathologies and aid in creating patient-centered management plans.