Evaluation and management of posterior shoulder instability

Assessment and diagnosis of non-traumatic shoulder instability: A scoping review

Background

Given its complexity, there is no consensus regarding the assessment of non-traumatic shoulder instability (NTSI) to this day. We, therefore, conducted a scoping review to map the existing white and grey literature regarding diagnostic and assessment tools for the NTSI population.

Method

We followed the Arksey and O'Malley five-stage guideline for the conduct of scoping reviews and searched through 12 electronic databases for English-language articles and reviews from 2000 to 2024 related to NTSI's diagnosis and assessment tools.

Results

Among the 3426 identified studies, 58 were included (describing 59 different interventions). Case-control studies (43.1%, 25/58) and narrative reviews (34.5%, 20/58) were the most prevalent. Diagnostic imaging was the most studied intervention (35.6%, 21/59). Twenty-seven studies specified a direction of instability, of which 59% (16/27) were multidirectional instability. Non-traumatic shoulder instability often affects young individuals, with complex symptoms, including neuromotor deficits, muscular imbalances and kinematic alterations, involving psycho-behavioural and somatosensory components.

Discussion

Non-traumatic shoulder instability's aetiologies and clinical manifestations are multifactorial. The prevalence and incidence of this dysfunction are probably underestimated. Clinical history is crucial to retrace a complex and chronic dysfunction. The use of orthopaedic shoulder tests and the routine use of imaging currently appear to have limited relevance as a first-line approach.

Posterior Shoulder Instability, Part I-Diagnosis, Nonoperative Management, and Labral Repair for Posterior Shoulder Instability-An International Expert Delphi Consensus Statement

PURPOSE

To establish consensus statements on the diagnosis, nonoperative management, and labral repair for posterior shoulder instability.

METHODS

A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating on the basis of their level of expertise in the field. Experts were assigned to 1 of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement.

RESULTS

Unanimous agreement was reached on the indications for nonoperative management and labral repair, which include whether patients had primary or recurrent instability, with symptoms/functional limitations, and whether there was other underlying pathology, or patient's preference to avoid or delay surgery. In addition, there was unanimous agreement that recurrence rates can be diminished by attention to detail, appropriate indication and assessment of risk factors, recognition of abnormalities in glenohumeral morphology, careful capsulolabral debridement and reattachment, small anchors with inferior placement and multiple fixation points that create a bumper with the labrum, treatment of concomitant pathologies, and a well-defined rehabilitation protocol with strict postoperative immobilization.

CONCLUSIONS

The study group achieved strong or unanimous consensus on 63% of statements related to the diagnosis, nonoperative treatment, and labrum repair for posterior shoulder instability. The statements that achieved unanimous consensus were the relative indications for nonoperative management, and the relative indications for labral repair, as well as the steps to minimize complications for labral repair. There was no consensus on whether an arthrogram is needed when performing advanced imaging, the role of corticosteroids/orthobiologics in nonoperative management, whether a posteroinferior portal is required.

LEVEL OF EVIDENCE

Level V, expert opinion.

The efficacy of conservative management of micro-traumatic posterior shoulder instability

Background

Microtraumatic posterior shoulder instability (PSI) is characterized by symptomatic posterior translation of the glenohumeral joint. A common etiology is a gradual overload of glenohumeral joint structures. The recommend initial treatment for microtraumatic PSI is rehabilitation; however, the evidence to support this recommendation is limited. The aim of this study is to investigate the patient- reported outcome measures and return to sport success of participants with microtraumatic PSI who participate in a posterior instability rehabilitation program.

Methods

In the single-group study design, 24 shoulders in 22 sporting participants (17 male, 5 females; mean age, 21.1 years, standard deviation 10.1 years) diagnosed with microtraumatic PSI undertook the Watson Posterior Instability Program (WIP-p) over 24 weeks. Outcome measures included the Melbourne Instability Shoulder Score and Western Ontario Shoulder Instability Index at baseline, 6, 12, and 24 weeks. Failure of conservative management and time to return to sport was measured. Treatment effects were determined using linear mixed models, with 95% confidence intervals. Significance was set at 0.05.

Results

After 24 weeks of the WIP-p, participants had significant improvements at 12 (effect size or standardized mean difference (SMD): 1.1, P < .001) and 24 weeks (SMD: 1.8, P < .001) on the Western Ontario Shoulder Instability Index and significant improvements at 6 (SMD; 0.74, P = .036), 12 (SMD: 0.41, P = .007) and 24 weeks (SMD: 1.7, P < .001) on the Melbourne Instability Shoulder Score. For return to sport, 20 of the 22 (90.1%) participants returned to full activity at the 24-week time point, while two went on to have reconstructive surgery.

Discussion and Conclusion

The WIP-p resulted in a high level of return to sport and significantly improved functional outcomes in patients with microtraumatic PSI. A small proportion of sporting participations with microtraumatic PSI may fail conservative rehabilitation and require surgical consideration.

Analysis of shoulder motion with inertial sensors in Poland syndrome patients

PURPOSE

Poland syndrome is a congenital malformation characterized by agenesis or hypoplasia of pectoralis muscles. There is a limited literature on how the anatomic anomalies of PS may impact the movement of the shoulder. This study analyzes the effects of absence of the pectoralis muscles on the shoulder kinematic.

METHODS

Clinical evaluation was performed analyzing range of motion (RoM), stability, cuff disease and internal rotation strength. In all patients, we used inertial sensors to analyze scapular motion in three degrees of freedom: medium-lateral rotation, posterior tilting and protraction-retraction. The same analysis was performed by dividing the patients into two groups by age to evaluate the presence of age-related alterations.

RESULTS

No differences in RoM between pathological and healthy side were observed. All patients were positive for posterior instability. No significant differences in strength in internal rotation were observed with average + 6,91% (s = 2,14) on the healthy side's strength. Kinematic analysis showed higher values of scapular medium-lateral rotation and anticipation of retraction of the pathological side during flexion and abduction. Reduced scapular tilt in under 18 years old was found.

CONCLUSIONS

The absence of the pectoralis muscles seems not to affect the RoM. The increased scapular rotation on the medium-lateral axis is probably due to the absence of humeral insertion of the pectoralis major and the absence of the scapular insertion of the pectoralis minor. The increased retraction in abduction it can be explained by a hypercontraction of the scapular stabilizers. The reduced tilt in under 18 years old is influenced by the lack of adaptation by the muscle groups involved.

The clinical and functional outcomes of closed reduction and arthroscopic McLaughlin procedure in patients with neglected locked posterior shoulder dislocation

INTRODUCTION

Posterior shoulder dislocation with a reverse Hill-Sachs lesion is a rare and complex injury, requiring specialized treatment due to the difficulty in diagnosis, reduction, and addressing both sides of the pathology to reduce the potential for recurrent dislocation.

PURPOSE

To evaluate the clinical and functional outcomes of closed reduction and arthroscopic McLaughlin procedure with posterior labral repair in patients with neglected locked posterior shoulder dislocation for less than 12 weeks.

METHODS

A prospective study was conducted at university hospitals, managing 15 patients with neglected locked posterior shoulder dislocation for less than 12 weeks and concomitant engaging reverse Hill-Sachs lesions of less than 40% of the humeral articular surface. They were treated with closed reduction and arthroscopic McLaughlin procedure with posterior labral repair. Patients' assessments included shoulder range of motion, pain levels using the visual analog scale (VAS) score, and functional outcome using the Oxford instability score and the University of California Los Angeles Shoulder Scale (UCLA) with at least 2 years of postoperative follow-up.

RESULTS

All 15 patients reported no recurrent dislocation and restored shoulder motion at the final follow-up. External rotation significantly improved from 0° to a mean of 65° in adduction, at 90° of abduction, the respective measurement was 85° (p < 0.01). Active forward flexion increased from 35° to 145° (p < 0.01). UCLA and Oxford instability scores Showed marked improvement (p < 0.01).

CONCLUSION

Closed reduction and arthroscopic McLaughlin procedure with posterior labral repair is a safe and effective way for managing patients with locked neglected posterior shoulder dislocations that have been neglected for less than 12 weeks with engaging reverse Hill-Sachs lesion defect, less than 40% of the humeral head.

Outcomes of arthroscopic stabilization for posterior shoulder instability: a systematic review

BACKGROUND

Posterior shoulder instability makes up approximately 10% of all shoulder instability cases and its diagnosis and treatment is less well understood. Recently, however, there has been increased recognition of posterior instability and posterior stabilization. The purpose of this study was to systematically review the literature to ascertain the outcomes on arthroscopic stabilization of posterior shoulder instability.

METHODS

Two independent reviewers conducted a systematic literature search based on PRISMA guidelines, utilizing the MEDLINE database. Studies were eligible for inclusion if they reported postoperative outcomes for posterior shoulder instability following arthroscopic stabilization.

RESULTS

A total of 48 studies met inclusion criteria for review including 2307 shoulders. Majority of patients were male (83.3%), with an average age of 26.1 years and a mean follow-up of 46.8 months. The functional outcome score primarily utilized for postoperative assessment was the American Shoulder and Elbow Surgeons with an average of 84.77. Overall, 90.9% of patients reported being satisfied with their arthroscopic stabilization. Recurrent instability occurred in 7.4% of patients. The total revision rate was 5.2%. 16.6% of patients reported residual pain postoperatively. The rate of return to play was 86.4% with 68.0% of patients returning to play at the same or higher level of play.

CONCLUSION

Arthroscopic stabilization of posterior shoulder instability resulted in good outcomes with high patient satisfaction and low rates of recurrent instability, revisions, and residual pain.

Batter's Shoulder: Diagnosis, Management, and Outcomes

Batter's shoulder is characterized by posterior shoulder instability in the lead (front) shoulder of a batting athlete. This most commonly occurs as a discrete event, particularly a swing and miss at an outside pitch, which leads to an episode of shoulder subluxation. A thorough history and physical examination is key to diagnosis, with patients feeling pain and instability of the lead shoulder when attempting the baseball swing or during pushing-type activities, as well as positive posterior labral signs in tests such as the Kim, jerk, and modified dynamic labral shear tests. Magnetic resonance imaging can confirm the diagnosis of posterior labral tear and may show concomitant pathologies such as a reverse Hill-Sachs lesion. Nonsurgical treatment is directed at rotator cuff and scapular strengthening; however, arthroscopic posterior labral repair is often required for definitive stabilization. Overall, this is a relatively rare diagnosis, but outcomes of surgical repair are favorable with high satisfaction and rates of return to competition.

No Difference in Recurrent Instability Between Knotted and Knotless Repair Techniques in Arthroscopic Treatment of Isolated Posterior Labral Tears: A Systematic Review

Purpose

To compare clinical failure, recurrent instability, patient-reported outcome measures (PROMs), and return to sport (RTS) between knotted and knotless fixation methods in arthroscopic posterior labral repair for isolated posterior shoulder instability (PSI).

Methods

Multiple databases were queried according to Preferred Reported Items for Systematic Reviews and Meta-Analyses guidelines for clinical studies with Level I to IV evidence, including knotted and knotless suture anchors for arthroscopic posterior labral repair. Combined anterior and posterior instability, multidirectional instability, SLAP injuries, unspecified repair techniques, majority open procedures, and revision surgery were excluded.

Results

Screening yielded 17 full-text articles reporting on 852 shoulders undergoing posterior labral repair. Recurrent instability ranged from 0% to 21%, and the rate of revision surgery ranged from 0% to 11% in knotted only, 0% in knotless only, and 2.0% to 8.1% in knotted and knotless studies. Six studies with both pre- and postoperative visual analog scale scores and 7 studies with both pre- and postoperative American Shoulder and Elbow Score scores all showed improvement in scores after intervention regardless of repair technique. Thirteen studies reported RTS or duty rates with a minimum of 79%.

Conclusions

Overall recurrent instability after posterior labral repair for isolated PSI was low with improvement in PROMs and favorable RTS rates regardless of fixation method. There was no clear difference in recurrent instability or revision surgery between knotted and knotless fixation methods for isolated posterior labral repair. However, the current literature is predominantly limited by Level III and IV evidence. The quality of literature and lack of standardization on the definition of clinical failure and recurrent instability among surgeons preclude any definitive conclusion regarding one clinically superior fixation method.

Level of Evidence

Level IV, systematic review of Level III and IV studies.

Diagnosing the direction of shoulder instability in rugby players

The muscular characteristics of rugby players may make diagnosing the direction of shoulder instability and labral pathology challenging. This study aimed to assess the accuracy of clinical examination and specifically instability tests, in diagnosing the direction of shoulder instability in rugby players. One-hundred-and-forty rugby players, who had undergone a shoulder stabilization procedure, over a 55-month period, were included in this study. The mean age was 21.5 years with 137 males. Data collected included clinical examination and intraoperative findings. The two were compared to calculate the diagnostic accuracy of special tests for instability. The Anterior Apprehension Test had good sensitivity (82.7%), specificity (100%) and PPV (100%) but poor NPV (55.8%). All posterior instability tests demonstrated a sensitivity of over 85%, but all had a specificity of 25% or less. In 83.6% of cases the direction of instability was correctly identified from history and examination. Anterior instability was correctly diagnosed in 78.9% of cases and posterior in 100.0%. The poor NPV of the anterior apprehension test suggests that clinicians should be suspicious of anterior instability in rugby shoulders even in the light of negative examination findings. Positive posterior instability tests are highly suggestive of posterior instability in rugby players.

Retrospective analysis of decision-making in post-traumatic posterior shoulder instability

PURPOSE

This study aims to assess the clinical outcomes in the management of post-traumatic posterior shoulder instability (PSI) with a focus on the decision-making process for operative and conservative treatments.

INTRODUCTION

PSI can result from traumatic events, impacting a patient's quality of life. This study delves to better indicate decision-making for operative indication of post-traumatic PSI patients.

METHODS

Patients who sustained posterior shoulder dislocations were selected from a single surgeon's database within a five-year period. Cases of degenerative or genetically caused PSI were excluded, resulting in a cohort of 28. Patients were initially managed conservatively but indicated for surgery if they were unable to actively stabilize the shoulder or exhibited bony or cartilage defects confirmed through imaging. If conservative treatment did not yield significant improvements, it was classified as a failure, and operative intervention was recommended. The WOSI Score, ROM, and X-ray were employed to evaluate the success of treatment.

RESULTS

Out of the 28 patients, 11 received conservative, seven immediate surgeries, and ten transitioned from conservative to operative treatment. The overall success rate showed 25 good to excellent results. In the persistent conservative treatment group, the initial WOSI score was significantly lower compared to the operative group.

CONCLUSION

This study suggests that post-traumatic PSI can be successfully managed conservatively with initial low clinical symptoms (low WOSI score) and in the absence of absolute indications for operative treatment. When surgery is necessary, arthroscopic procedures proved effective in achieving good to excellent results in 16 out of 17 cases.

Clinical, Diagnostic, and Therapeutic Characteristics of Posterior Glenohumeral Instability

Posterior shoulder instability (PSI) is a shoulder pathology that is challenging to diagnose, leading to treatment delay and exacerbation of symptoms. Etiology can be both traumatic and atraumatic, and a comprehensive clinical history plays a significant role in achieving diagnosis. Imaging in the setting of PSI can reveal a reverse-Bankart lesion, a reverse Hill-Sachs lesion, posterior labral cysts, and potentially glenoid or lesser tuberosity fractures. Both conservative and surgical options exist for patients with PSI, and management often depends on case severity, extent of bone loss, and patient goals and expectations. Holistic patient education regarding the etiologies, mechanisms and possible treatment options available is pivotal for achieving high levels of patient satisfaction and optimal outcomes.

Favorable short-term outcomes of micronized allogenic cartilage scaffold for glenoid cartilage defects associated with posterior glenohumeral instability

Purpose

To determine clinical outcomes associated with micronized allogenic cartilage scaffold use for treatment of posterior glenoid cartilage defects at 2 years.

Study Design

Case series.

Methods

A retrospective analysis of prospectively collected data was performed on a consecutive series of patients who underwent arthroscopic treatment of a symptomatic posterior glenoid cartilage defect with micronized allogenic cartilage scaffold between January 2019 and December 2020. The primary outcome was subjective shoulder value (SSV) at latest follow-up. Secondary outcomes included visual analog scale (VAS), recurrence of instability, and range of motion (ROM).

Results

Seven patients, including 4 in the setting of primary posterior instability and 3 in the setting of recurrent symptoms after arthroscopic posterior glenohumeral stabilization, were included in the analysis with a mean follow up of 2.6 years (range, 2-3.7 years). Statistically significant improvements were seen in SSV (median = 40, interquartile range [IQR] = 40-50 before surgery; vs median = 85, IQR = 67.5-87.5 after surgery; P = .018) and VAS (median = 4, IQR = 4-6.3 before surgery; vs median = 1, IQR = 0-1.5 after surgery; P = .010). No significant differences were seen in ROM. There were no cases of recurrent instability or reoperation.

Conclusions

The use of micronized allogenic cartilage scaffold for glenoid cartilage defects is associated with clinical improvement at 2-year follow-up. This is the case when performed in conjunction with index posterior labral repair when there is a concomitant glenoid cartilage defect or when performed in the setting of persistent pain and mechanical symptoms after prior posterior labral repair.

Level of Evidence

Level IV, therapeutic case series.

Physical therapy management of an athlete with a Kim lesion using physical agents, manual therapy, and therapeutic exercise: a case report

BACKGROUND

Several operative procedures have been described for treating a Kim lesion. However, no physical therapy intervention has been documented as conservative treatment for these cases.

OBJECTIVE

The purpose of this report was to describe a physical therapy management protocol for an athlete with a Kim lesion.

CASE DESCRIPTION

A 22-year-old female volleyball athlete presented to physical therapy with an 8-month history of right shoulder pain when performing the serve and attack sports gestures. Pain was 5/10 on the visual analogue scale (VAS). Pain was localized along the glenohumeral joint, around the long head of the biceps brachii tendon, and at the subscapularis tendon insertion. Shoulder range of motion (ROM) was limited to flexion (150°), abduction (158°), and internal rotation (80°). Kim lesion was confirmed by clinical tests (Kim test and Jerk test) and via magnetic resonance imaging. Shoulder functional outcomes were verified through the University of California Los Angeles (UCLA) shoulder rating scale. Upper extremity sensorimotor control was verified in bimanual support by stabilometry on a baropodometer. Core function was assessed through a plank test and a side plank test. The 8-week course of treatment included manual therapy, physical agents, shoulder and scapular mobilizations, resistance and sensorimotor exercises, core strengthening, and functional exercises.

OUTCOMES

Physical therapy interventions resulted in a decrease in VAS pain (3/10), an increase in shoulder ROM (10.8°) and in UCLA shoulder score (from 22 to 33 points), a reduction in the center of pressure displacement (27-56%), and an increase in plank test (45%) and side plank test (21-29%) performance. The athlete had a full return to sport after the treatment.

CONCLUSION

We concluded that the protocol used for conservative management of Kim lesion resulted in clinical satisfactory physical and functional outcomes for the athlete.

Determining the True Incidence of Glenohumeral Instability Among Players in the National Football League: An Epidemiological Study of Non-Missed Time Shoulder Instability Injuries

Background

Shoulder instability encompasses a spectrum of glenohumeral pathology ranging from subluxation to dislocation. While dislocation frequently leads to removal from play, athletes are often able to play through subluxation. Previous research on glenohumeral instability among athletes has largely focused on missed-time injuries, which has likely disproportionately excluded subluxation injuries and underestimated the overall incidence of shoulder instability.

Purpose

To describe the epidemiology of shoulder instability injuries resulting in no missed time beyond the date of injury (non-missed time injuries) among athletes in the National Football League (NFL).

Study Design

Descriptive epidemiology study.

Methods

The NFL's electronic medical record was retrospectively reviewed to identify non-missed time shoulder instability injuries during the 2015 through 2019 seasons. For each injury, player age, player position, shoulder laterality, instability type, instability direction, injury timing, injury setting, and injury mechanism were recorded. For injuries that occurred during games, incidence rates were calculated based on time during the season as well as player position. The influence of player position on instability direction was also investigated.

Results

Of the 546 shoulder instability injuries documented during the study period, 162 were non-missed time injuries. The majority of non-missed time injuries were subluxations (97.4%), occurred during games (70.7%), and resulted from a contact mechanism (91.2%). The overall incidence rate of game-related instability was 1.6 injuries per 100,000 player-plays and was highest during the postseason (3.5 per 100,000 player-plays). The greatest proportion of non-missed time injuries occurred in defensive secondary players (28.4%) and offensive linemen (19.8%), while kickers/punters and defensive secondary players had the highest game incidence rates (5.5 and 2.1 per 100,000 player-plays, respectively). In terms of direction, 54.3% of instability events were posterior, 31.9% anterior, 8.5% multidirectional, and 5.3% inferior. Instability events were most often anterior among linebackers and wide receivers (50% and 100%, respectively), while posterior instability was most common in defensive linemen (66.7%), defensive secondary players (58.6%), quarterbacks (100.0%), running backs (55.6%), and tight ends (75.0%).

Conclusion

The majority of non-missed time shoulder instability injuries (97.4%) were subluxations, which were likely excluded from or underreported in previous shoulder instability studies due to the inherent difficulty of detecting and diagnosing shoulder subluxation.

Trends in the surgical treatment of posterior shoulder instability in the United States from 2016 to 2020

Background

The purpose of this study was to describe trends in the incidence of open versus arthroscopic management of posterior shoulder instability (PSI) as well as the patients undergoing these procedures in the United States over time.

Methods

The PearlDiver Patient Records Database was utilized for this study. Cases of PSI and surgery were identified via the appropriate ICD-10-CM and CPT codes. Linear regression and two-sample Student's t-test were used to analyze incidence rates, procedure type, number of instability events, and patient age.

Results

A total of 5655 patients were identified as having PSI, undergoing a total of 686 capsulorraphies. The incidence of PSI treated surgically increased across the years of the study at a rate of 0.0293 per 100,000 person-years with an incidence in 2019-2020 greater than in 2016-2018 (p = 0.0151). Patients undergoing arthroscopic capsulorrhaphy were on average younger than those undergoing open capsulorrhaphy (p = 0.0021). Patients experienced a higher number of posterior instability events before open surgery compared to arthroscopic (p = 0.0274).

Discussion

The incidence of surgical treatment of PSI in the United States is steadily rising, with greater than 90% of cases being treated arthroscopically. Those undergoing arthroscopic posterior stabilization are both younger and face fewer instability events prior to surgery.

Lack of Consensus in Rehabilitation Protocols After Posterior Shoulder Stabilization

Background

Posterior shoulder instability is being identified and treated more frequently by orthopaedic providers. After posterior shoulder stabilization, long-term outcomes in function and mobility are largely dependent on the postoperative rehabilitation period. Thus, it is important to assess the consistency between protocols at different institutions.

Purpose/Hypothesis

The purpose of this study was to investigate the variability among rehabilitation protocols published by academic orthopaedic programs and their affiliates. It was hypothesized that there would be little consistency in the duration of immobilization, timing of functional milestones, and start dates of various exercises.

Study Design

Cross-sectional study.

Methods

Rehabilitation protocols after posterior shoulder stabilization that were published online from Accreditation Council for Graduate Medical Education (ACGME)-accredited orthopaedic surgery programs and their affiliates were evaluated for recommendations on immobilization, exercises, activities, range of motion (ROM), and return-to-sport goals.

Results

Of the 204 ACGME-accredited orthopaedic surgery programs, 22 programs and 17 program affiliates had publicly available rehabilitation protocols that were included for review. There were 37 programs (94.9%) that recommended the use of sling immobilization for a mean of 4.7 ± 1.8 weeks postoperatively. Active ROM of the elbow, wrist, and hand was the most common early ROM exercise to be recommended (36 programs; 92.3%). The goal of 90° passive external rotation demonstrated the widest range of recommended start dates (0-12 weeks postoperatively). Late ROM exercises and start dates varied between protocols, with the largest standard deviation found in achieving full active ROM (13.5 ± 3.6 weeks). Resistance exercises showed a wide range of recommended start dates. Bench presses and push-ups began, on average, at 13.1 ± 3.4 and 15.3 ± 3.2 weeks, respectively. Return to sport was recommended at 21.7 ± 3.6 weeks.

Conclusion

There was a high level of variability in postoperative rehabilitation protocols after posterior shoulder stabilization among orthopaedic programs and their affiliates, suggesting that a standard protocol for rehabilitation has yet to be established.

Open and arthroscopic posterior bone block with iliac crest autograft for posterior shoulder instability - systematic review of clinical and radiological outcomes

INTRODUCTION

Posterior shoulder instability (PSI) is a rare and challenging pathology to manage. The aim of this review was to assess and compare whether open and arthroscopic iliac crest bone graft (ICBG) bone block procedures succeeded in improving functional and clinical outcomes as well as radiological outcomes of union and graft resorption.

HYPOTHESIS

We hypothesised that there will be no difference in recurrence rate and functional outcome between open and arthroscopic procedures but there will be a higher complication rate with open bone block procedures.

METHODS

A systematic review was conducted in accordance with PRISMA guidelines using the online databases MEDLINE and Embase. The review was registered on the PROSPERO database. Studies of open or arthroscopic ICBG bone block procedures reporting patient reported outcome measures, recurrence, complications and progression to osteoarthritis and radiological outcomes of graft union and resorption were selected. Studies were appraised using the Methodical index for non-randomised studies (MINORS) tool.

RESULTS

14 studies satisfied the inclusion criteria; five studies were arthroscopic and nine used open techniques. A total of 183 patients and 201 shoulders were included, mean age was 25 years range (14-75 years). Recurrent instability ranged from 0% to 12.5% for arthroscopic and 0% to 36.4% for open studies. Arthroscopic studies had statistically significant increases in numerous functional outcome scores but there was no evidence for similar improvements in open studies. Osteoarthritis at follow-up ranged from 12.5% to 47% in arthroscopic and 0% to 81.8% for open studies. Arthroscopic complication rate ranged from 6.7% to 75% compared to 0% to 80% for open studies. Majority of complications were metalware related requiring surgical intervention. Partial graft resorption ranged from 7.7-100% after arthroscopic and 4.8-100% after open procedures. High union rates were seen with both open and arthroscopic techniques.

CONCLUSION

This study highlights a lack of high-level evidence for arthroscopic and open posterior bone block procedures using ICBG to manage PSI. Functional and instability outcome scores showed significant improvement with arthroscopic ICBG bone block procedures however limited evidence was available for open studies. Metalwork related complications requiring revision and radiographic progression to osteoarthritis was high in both arthroscopic and open studies.

LEVEL OF EVIDENCE

IV, systematic review.

Single-Portal Arthroscopic Posterior Capsulorrhaphy for Recurrent Shoulder Capsule Laxity and Instability

Arthroscopic stabilization for posterior shoulder instability is well documented in the literature, offering good to excellent clinical outcomes after injury with favorable return-to-sport and patient satisfaction rates. Posterior capsulorrhaphy addresses recurrent laxity by decreasing the size of the posterior capsule through arthroscopic placement of sutures, in addition to addressing posterior labral tears and any intra-articular pathology within the joint. This technical note describes an arthroscopic posterior capsulorrhaphy for recurrent posterior shoulder capsule laxity and instability in an active patient. This technique uses a single posterior working portal and 2 suture anchors to tighten the posterior capsule onto the intact labrum.

Indications and outcomes of glenoid osteotomy for posterior shoulder instability: a systematic review

Background

There is limited evidence examining glenoid osteotomy as a treatment for posterior shoulder instability.

Methods

A search of Medline, Embase, PubMed and Cochrane Central Register of Controlled Trials was conducted from the date of origin to 28th November 2019. Nine out of 3,408 retrieved studies met the inclusion criteria and quality was assessed using the Methodological Index for Non-randomized Studies tool.

Results

In 356 shoulders, the main indication for osteotomy was excessive glenoid retroversion (greater than or equal to approximately −10°). The mean preoperative glenoid version was −15° (range, −35° to −5°). Post-operatively, the mean glenoid version was −6° (range, −28° to 13°) and an average correction of 10° (range, −1° to 30°) was observed. Range of motion increased significantly in most studies and all standardized outcome scores (Rowe, Constant–Murley, Oxford instability, Japan Shoulder Society Shoulder Instability Scoring and mean shoulder value) improved significantly with high rates of patient satisfaction (85%). A high complication rate (34%, n = 120) was reported post-surgery, with frequent cases of persistent instability (20%, n = 68) and fractures (e.g., glenoid neck and acromion) (4%, n = 12). However, the revision rate was low (0.6%, n = 2).

Conclusion

Glenoid osteotomy is an appropriate treatment for posterior shoulder instability secondary to excessive glenoid retroversion. However, the high rate of persistent instability should be considered when making treatment decisions. Level of Evidence: Systematic review; Level 4

Single-Portal Arthroscopic Posterior Shoulder Stabilization

Posterior shoulder instability occurs when the labrum detaches posteriorly from the glenoid owing to significant trauma and is a relatively uncommon type of shoulder dislocation. Although posterior instability has often been treated with open shoulder stabilization, modern arthroscopic procedures are being rapidly pursued by surgeons as an improved option because of decreased invasiveness and reduced operative times. Arthroscopic stabilization of the posterior glenoid labrum typically involves 2 working portals, but the procedure still yields successful results when performed with a single posterior portal and a suture passer. Our technique involves 1 less portal to reduce invasiveness, lower the risk of nerve damage, and decrease the operative time and postoperative pain. The purpose of this article is to describe an arthroscopic posterior stabilization technique with a single working portal.

Outcomes of posterior labral repair with or without concomitant high-grade glenohumeral chondral pathology: a retrospective cohort with minimum 2-year follow-up

BACKGROUND

The purpose of this study was to compare outcomes of patients who underwent posterior labral repair with and without concomitant glenohumeral chondral pathology.

METHODS

A retrospective review was performed on patients aged ≥18 years who underwent primary posterior labral repair over 5 years. Charts were reviewed to determine the presence and location of high-grade (Outerbridge grade III or IV) pathology. Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), Western Ontario Stability Index (WOSI), visual analog scale (VAS), and Simple Shoulder Test (SST) scores were collected at median 71.5-month follow-up and compared between patients with and without concomitant chondral pathology during the index procedure.

RESULTS

Of 100 patients who underwent primary posterior labral repair, 43% had glenoid and/or humeral-sided high-grade chondral pathology. Patients with chondral pathology were older than those without (P < .001). A higher proportion of patients with chondral pathology underwent concomitant biceps tenodesis (19.3% vs. 37.2%, P = .046). The type of anchor (all-suture or solid body, P = .010) used was different between patients with and without chondral pathology at time of posterior labrum repair. There was no difference in reoperation rates at final follow-up between patients with and without chondral damage at time of index procedure (P = .200). All outcome scores were similar between all comer patients with and without chondral pathology. Isolated glenoid pathology was significantly associated with lower QuickDASH (P = .018), higher SST (P = .013), lower VAS (P = .016), and lower WOSI scores (P = .046) compared to patients with bipolar lesions. After stratifying by age, there was an association between chondral pathology and lower VAS and WOSI scores in patients aged <35 years, and there was an association between chondral pathology and lower SST scores in patients aged ≥35 years.

CONCLUSION

Based on median QuickDASH, SST, WOSI, and VAS scores, subjective and functional outcomes after primary arthroscopic posterior labral repair were not negatively influenced by the presence of concomitant chondral damage at the time of surgery for patients aged <35 years at minimum 2-year follow-up. Although our primary outcome score, the QuickDASH, was not significantly associated with the presence of chondral damage in patients aged >35 years, SST scores were negatively influenced by concomitant chondral damage in this older cohort, but this may not be adequately powered. It appeared that patients with chondral damage localized to the glenoid tended to have better outcomes scores that those with bipolar damage.

Posterior glenoid bone block transfer for posterior shoulder instability: a systematic review

BACKGROUND

The purpose of this study is to systematically review the literature and evaluate patient-reported outcomes and complication/revision rates of bone block augmentation in the treatment of posterior shoulder instability (PSI).

METHODS

PubMed was searched according to PRIMSA guidelines to find clinical studies evaluating patient-reported outcomes, revision, and complication rates in posterior bone block for PSI. A literature search of MEDLINE, EMBASE, and the Cochrane Library was performed based on the PRISMA guidelines. Clinical studies reporting on the complications following posterior bone block were included.

RESULTS

Overall, 11 studies (level of evidence [LOE] III: 2, LOE IV: 9) met inclusion criteria, with 225 shoulders. Recurrent instability after the posterior bone block was found to be 9.8%. The overall complication rate was 13.8%, with 0.89% having graft complications, 11.1% having hardware complications, 0.4% having wound complications, 0.4% having nerve complications, and 0.89% having other complications. Residual pain was found in 11.6% of shoulders operated on. Patient-reported outcomes were evaluated most commonly by Rowe (81.4%), Constant (84.6%), and Walch-Duplay scores (81.6%).

CONCLUSION

There is a moderate rate of recurrence following posterior bone block for PSI. However, the patient-reported outcomes are high despite there being commonly reported persistent shoulder pain postoperatively.

Anatomic Total Shoulder Arthroplasty versus Hemiarthroplasty for Glenohumeral Osteoarthritis: A Systematic Review and Meta-Analysis

Purpose: Both anatomic total shoulder arthroplasty (TSA) and shoulder hemiarthroplasty (SHA) are used for the management of end-stage glenohumeral osteoarthritis (GHOA). The present study compared TSA and SHA in terms of clinical outcome and complication rate. Methods: This meta-analysis followed the PRISMA guidelines. In October 2021, the following databases were accessed: Web of Science, Google Scholar, Pubmed, Scopus. All clinical trials comparing anatomical TSA versus SHA for GHOA were considered. Results: Data from 11,027 procedures were retrieved. The mean length of the follow-up was 81.8 (16 to 223.20) months. The mean age of the patients was 61.4 ± 8.6 years, and 56.0% (5731 of 10,228 patients) were women. At last follow-up, the age-adjusted constant score was greater following TSA (p < 0.0001), as were active elevation (p < 0.0001), flexion (p < 0.0001), abduction (p < 0.0001), and American Shoulder and Elbow Surgeons Shoulder Score (p < 0.0001). Postoperative pain (p < 0.0001) and revision rate (p = 0.02) were lower in the TSA group. Conclusions: Anatomic TSA performed better than SHA in patients with GHOA.

Glenohumeral Joint Instability: A Review of Anatomy, Clinical Presentation, and Imaging

The glenohumeral joint is intrinsically predisposed to instability because of the bony anatomy but maintained in alignment by many important structures, including the glenoid labrum, glenohumeral ligaments (GHLs), and muscles and tendons. Trauma and overuse can damage these stabilizers, which may then lead to subluxation or dislocation and eventually recurrent instability. This is most common in the anterior direction, which has several recognizable patterns of injury on advanced imaging, including humeral Hill Sachs deformities, bony Bankart lesion of the anteroinferior glenoid, soft tissue Bankart lesions, Bankart variant lesions (Perthes and ALPSA lesions), and HAGL/GAGL lesions. Similar reverse lesions are seen, as well as unique posterior lesions, such as Bennett and Kim's lesions. When symptoms of apprehension and instability in more than one direction are seen, one should consider multidirectional instability, which often presents with a patulous joint capsule. Finally, owing to significant impacts of daily activities and quality of life, surgical correction of labral tears, bony Bankart defects, Hill Sachs defects, and capsular laxity, may be considered.

Epidemiology of Shoulder Instability in the National Football League

Background

Shoulder instability is a common and potentially debilitating injury among collision sport athletes that can lead to long-term damage of the glenohumeral joint. Limited data exist regarding instability among elite athletes in the National Football League (NFL).

Purpose

To describe the epidemiology of shoulder instability in the NFL from 2012 through 2017.

Study Design

Descriptive epidemiology study.

Methods

The NFL's injury database was reviewed for shoulder instability injuries resulting in missed time during the study inclusion dates. Injuries were classified by type and direction, as well as timing, setting, and mechanism. Median missed time was determined for the different types and directions of instability. Incidence rates for game-related injuries were calculated based on timing during the season and player position. Finally, the relationship between player position and instability direction was assessed.

Results

During the 6-year study period, 355 players sustained 403 missed-time shoulder instability injuries. Most injuries occurred during games (65%) via a contact mechanism (85%). The overall incidence rate of game-related instability was 3.6 injuries per 100,000 player-plays and was highest during the preseason (4.9 per 100,000 player-plays). The defensive secondary position accounted for the most injuries, but quarterbacks had the highest incidence rate in games (5.5 per 100,000 player-plays). Excluding unspecified events (n = 128; 32%), 70% (n = 192) of injuries were subluxations and 30% (n = 83) were dislocations; 75% of dislocations were anterior, while subluxations were more evenly distributed between the anterior and posterior directions (45% vs 52%, respectively). Players missed substantially more time after dislocation compared with subluxation (median, 47 days vs 13 days, respectively). When instability direction was known, the majority of instability events among quarterbacks and offensive linemen were posterior (73% and 53%, respectively), while anterior instability was most common for all other positions.

Conclusion

Shoulder instability is a common injury in the NFL and can result in considerable missed time. Dislocations occur less frequently than subluxations but lead to greater time lost. While most dislocations are anterior, more than half of subluxations are posterior, which is likely the result of repetitive microtrauma to the posterior capsulolabral complex sustained during sport-specific motions such as blocking. The risk of instability varies by player position, and position may also influence instability direction.

Return to Play After Arthroscopic Stabilization for Posterior Shoulder Instability-A Systematic Review

Purpose

To ascertain the rate and timing of return to play (RTP) and the availability of specific criteria for safe RTP after arthroscopic posterior shoulder stabilization.

Methods

Medline, EMBASE, and the Cochrane Library were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to find studies on arthroscopic posterior shoulder stabilization. Studies were included if they reported RTP data or rehabilitation protocols and excluded if concomitant procedures influenced the rehabilitation protocol. Rate and timing of RTP, along with rehabilitation protocols, were assessed.

Results

This review found 25 studies, including 895 cases, meeting the study’s inclusion criteria. The majority of patients were male (82.7%), with an age range of 14 to 66 years and a follow-up range of 4 to 148.8 months. The overall RTP rate ranged from 62.7% to 100.0%, and 50.0% to 100.0% returned to the same level of play. Among collision athletes, the overall rate of RTP was 80.0% to 100.0%, with 69.2%-100.0% returning to the same level of play. In overhead athletes, the overall rate of RTP was 85.2% to 100.0%, with 55.6% to 100.0% returning to the same level of play. Four studies (128 patients) specifically addressed the timing of RTP, and the range to RTP was 4.3 to 8.6 months. Specific RTP criteria were reported in a majority of studies (60%), with the most reported item being restoration of strength (44%).

Conclusion

There is a high rate of return to sport after arthroscopic posterior shoulder stabilization, ranging from 4.3 to 8.6 months after surgery. Return to preinjury level is higher for collision athletes compared with overhead athletes. However, there is inadequate reporting of RTP criteria in the current literature, with no clear timeline for when it is safe to return to sport.

Level of Evidence

IV, systematic review of level II to IV studies

Posterior Shoulder Instability Classification, Assessment, and Management: An International Delphi Study

OBJECTIVE

To reach consensus among international shoulder experts on the most appropriate assessment and management strategies for posterior shoulder instability (PSI).

DESIGN

Delphi.

METHODS

In phase 1 of the study, we reviewed the literature, generated the Delphi items, created the survey, and identified clinical experts. In phase 2 of the study, clinical shoulder experts (physical therapists, orthopaedic surgeons, sports medicine physicians, and researchers) participated in a 3-round e-Delphi survey. For consensus, we required a minimum of 70% agreement per round. Descriptive statistics were used to present the characteristics of the respondents, the response rate of the experts in each round, and the consensus for PSI classification, assessment, and management.

RESULTS

Round 3 was completed by 47 individuals from 5 different countries. The response rate ranged from 57/70 (81%) to 47/50 (94%) per round. Respondents agreed on 3 subgroups to define PSI: traumatic (100% agreement), microtraumatic (98% agreement), and atraumatic (98% agreement).

CONCLUSION

International shoulder experts agreed that the clinical presentation, management strategy, and outcome expectations differ for traumatic, microtraumatic, and atraumatic PSI. Their recommendations provide a framework for managing these subgroups, with additional consideration of sport and work participation and subsequent risks. J Orthop Sports Phys Ther 2020;50(7):373-380. Epub 29 Apr 2020. doi:10.2519/jospt.2020.9225.

Glenoid Cartilage Lesions Compromise Outcomes of Surgical Treatment for Posterior Shoulder Instability

Background:

Posterior shoulder instability is associated with nonspecific symptoms, including pain, subluxation, and functional impairment, which complicate its diagnosis and management. Owing to the rarity of the condition, there are no present decision tools for its diagnosis and treatment.

Purpose:

To investigate demographic, lesional, and surgical factors that influence functional outcomes in patients treated for posterior shoulder instability.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

We analyzed the clinical and radiographic records of 150 patients treated surgically for isolated posterior shoulder instability at 10 centers between 2000 and 2015, of which 144 were eligible for inclusion: 114 men (79%) and 30 women (21%) (mean ± SD age, 28.7 ± 9.6 years). The mean time between onset of symptoms and surgery was 66 ± 75 months. Shoulder instability was of traumatic origin in 115 patients (80%). The primary treatment was bone-block procedures for 65 patients (45%), posterior Bankart repair for 67 (47%), and capsular plication for 12 (8%). Patients were assessed with the Constant and Walch-Duplay scores at a mean follow-up of 51 ± 32 months (range, 12-159 months). Uni- and multivariable regression analyses were performed to determine associations between clinical scores and sex, age, traumatic origin, type of lesion, type of procedure, and follow-up.

Results:

At final follow-up, subluxations or dislocations recurred in 24 patients (17%). The overall Constant score was 86.2 ± 14.5, with a pain component of 12.6 ± 3.5. The Walch-Duplay score was 79.8 ± 24.2. Multivariable regressions revealed that the presence of a glenoid cartilage lesion was the only factor associated with worse Constant score (beta = –10; P = .013) and Walch-Duplay score (beta = –16.7; P = .024) across all subcomponents.

Conclusion:

The only factor that jeopardized functional outcomes of posterior instability surgery was the presence of glenoid cartilage lesions. Knowing that shoulders with glenoid cartilage lesions are at greater risk of residual pain or instability could help manage patient expectation and justify faster intervention before lesions deteriorate.

Posterior Glenohumeral Capsular Reconstruction With Modified McLaughlin for Chronic Locked Posterior Dislocation

Posterior instability is relatively rare when compared with anterior instability but can comprise up to 40% of operatively treated instability cases. Posterior dislocations are much rarer and are classically due to trauma, seizure, or electric shock. Due to a lack of an obvious deformity and an internally rotated and adducted arm position, posterior shoulder dislocations often are missed on initial presentation. In the management of posterior dislocations, considerations need to be made in regard to bony and soft-tissue pathology. In the setting of soft-tissue deficiency, previous options included nonoperative management primarily consisting of bracing and activity modification as well as arthroplasty options that do not rely on the capsulolabral complex for stability. In this paper, we present a technique for treating a chronic posterior shoulder dislocation with an associated large reverse Hill-Sachs deformity. In this setting, a revision labral repair and capsulodesis is generally not possible due to insufficient capsulolabral tissues. Here, we present the technique for an arthroscopic posterior capsule reconstruction using an acellular dermal allograft as well as a McLaughlin procedure for the treatment of a reverse Hill-Sachs lesion.

History of surgical stabilization for posterior shoulder instability

Background

Posterior shoulder instability is common in young athletes. Although the posterior shoulder instability literature is less robust than its anterior counterpart, many surgical procedures have been developed and refined over the past several centuries to address this condition.

Materials and methods

This article represents a retrospective historical analysis of the most common procedures used to treat posterior shoulder instability after sports injuries. A systematic approach to obtain published information on posterior shoulder instability was performed using the PubMed/MEDLINE database, manual searches of high–impact factor journals, and conference proceedings and books.

Results

A wide array of both soft tissue–based and bone-based procedures have been developed for the treatment of posterior shoulder instability, ranging from procedures addressing the soft tissue alone (capsular shift, labral repair, reverse Putti-Platt) or bone-based procedures (glenoid and/or humeral osteotomy, glenoid bone block) to a combination of both bone and soft-tissue procedures (modified McLaughlin procedure).

Discussion

Over the past several centuries, a number of procedures have been developed to address posterior shoulder instability, particularly as this pathology has become better understood. Future work is required not only to continue to advance these procedures but also to assess their outcomes. An understanding of the historical perspective of posterior shoulder instability procedures is essential as surgeons continue to modify these procedures in an effort to best help their patients.

Radiographic/MR Imaging Correlation of the Shoulder

This article discusses the typical findings seen on conventional radiography in 3 common shoulder pathologies, namely glenohumeral instability, rotator cuff pathology, and acromioclavicular joint dislocation. Correlative MR images are used to explain and illustrate the significance of radiographic findings that suggest the presence of underlying shoulder pathology.

Outcomes of Arthroscopic Posterior Shoulder Stabilization in the Beach-Chair Versus Lateral Decubitus Position: A Systematic Review

Background:

Arthroscopic posterior shoulder stabilization can be performed with patients in the beach-chair (BC) and the lateral decubitus (LD) positions; however, the impact of patient positioning on clinical outcomes has not been evaluated.

Purpose:

To compare clinical outcomes and recurrence rates after arthroscopic posterior shoulder stabilization performed in the BC and LD positions.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review using PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines was performed by searching PubMed, Embase, and the Cochrane Library for studies reporting the clinical outcomes of patients undergoing arthroscopic posterior shoulder stabilization in either the BC or LD position. All English-language studies from 1990 to 2017 reporting clinical outcomes after arthroscopic posterior shoulder stabilization with a minimum 2-year follow-up were reviewed by 2 independent reviewers. Data on the recurrent instability rate, return to activity or sport, range of motion, and patient-reported outcome scores were collected. Study methodological quality was evaluated using the Modified Coleman Methodology Score (MCMS) and Quality Appraisal Tool (QAT).

Results:

A total of 15 studies (11 LD, 4 BC) with 731 shoulders met the inclusion criteria, including 626 shoulders in the LD position (mean patient age, 23.9 ± 4.1 years; mean follow-up, 37.5 ± 10.0 months) and 105 shoulders in the BC position (mean patient age, 27.8 ± 2.2 years; mean follow-up, 37.9 ± 16.6 months). There was no significant difference in the overall mean recurrent instability rate between the LD and BC groups (4.9% ± 3.6% vs 4.4% ± 5.1%, respectively; P = .83), with similar results in a subanalysis of studies utilizing only suture anchor fixation (4.9% ± 3.6% vs 3.2% ± 5.6%, respectively; P = .54). There was no significant difference in the return-to-sport rate between the BC and LD groups (96.2% ± 5.4% vs 88.6% ± 9.1%, respectively; P = .30). Range of motion and other patient-reported outcome scores were not provided consistently across studies to allow for statistical comparisons.

Conclusion:

Low rates of recurrent shoulder instability and high rates of return to sport can be achieved after arthroscopic posterior shoulder stabilization in either the LD or the BC position. Additional long-term randomized trials comparing these positions are needed to better understand the potential advantages and disadvantages of surgical positioning for posterior shoulder stabilization.

Biomechanics of posterior shoulder instability - current knowledge and literature review

Posterior instability of the shoulder is a rare condition and represents about 10% of shoulder instability. It has become more frequently recognized in the last year, even though it is more difficult to diagnose than anterior shoulder instability. As this form of shoulder pathology is somewhat rare, biomechanical knowledge is limited. The purpose of our study was to perform an extensive literature search, including PubMed and Medline, and to give an overview of the current knowledge on the biomechanics of posterior shoulder instability. The PubMed/Medline databases were utilized, and all articles related to posterior shoulder instability and biomechanics were included to form a comprehensive compilation of current knowledge. A total of 93 articles were deemed relevant according to our inclusion and exclusion criteria. As expected with any newly acknowledged pathology, biomechanical studies on posterior shoulder instability remain limited in the literature. Current biomechanical models are performed in a static manner, which limits their translation for explaining a dynamic pathology. Newer models should incorporate dynamic stabilization of both the rotator cuff and scapulothoracic joint. There is a current lack of knowledge with regards to the pathomechanism of posterior shoulder instability, with no consensus on appropriate treatment regimens. Further investigation is therefore required at both basic science and clinical levels.

Effect of Posterior Glenoid Labral Tears at the NFL Combine on Future NFL Performance

Background:

Posterior labral injuries have been recognized as a particularly significant clinical problem in collision and contact athletes.

Purpose:

To evaluate the effect that posterior labral tears have on early National Football League (NFL) performance based on position, associated injuries, and operative versus nonoperative management.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective review of all participants in the NFL Combine from 2009 to 2015 was performed using medical and imaging reports documented at the combine. Magnetic resonance imaging scans were analyzed for tear location, associated injuries, and evidence of previous surgical interventions. Each player’s NFL draft position, as well as number of games played, number of games started, and snap percentage in his first 2 NFL seasons were collected for performance analysis and were compared with a control group of uninjured counterparts.

Results:

Players with posterior labral tears were selected significantly later in the draft than those in the control group (draft position, 171.6 vs 156.1, respectively; P = .017). Although no single individual position was significantly affected by posterior labral tears, linemen (both offensive and defensive) with posterior labral tears were drafted significantly later than those without tears (draft position, 164.0 vs 137.7, respectively; P = .018) and had a significantly lower percentage of snaps in their first NFL season (23.8% vs 27.7%, respectively; P = .014). Players who underwent surgical management before the combine had a significantly higher percentage of snaps in their second NFL season than those who were managed conservatively (31.4% vs 22.3%, respectively; P = .022). None of the concomitant injuries recorded (superior labral anterior-posterior tears, glenoid bone loss, reverse Hill-Sachs lesions, rotator cuff tears, reverse humeral avulsions of the glenohumeral ligament, and posterior labral tears combined with anterior tears) significantly affected the draft position, number of games played, number of games started, or snap percentage for the cohort as a whole or any specific position.

Conclusion:

Posterior labral tears did negatively and significantly affect early NFL outcomes for collegiate football players across several different metrics, especially among linemen. While operative management did not produce significantly superior performance in most outcome measures, it may allow for better longevity of the shoulder and warrants further investigation. Concomitant shoulder injuries did not significantly affect early NFL outcomes in this cohort.

A comprehensive rehabilitation program for posterior instability of the shoulder

Posterior shoulder instability is recognised as being less prevalent than anterior instability, however the diagnosis of this pathology is easily overlooked or missed and this may contribute to an underestimation of prevalence. Recently, there has been increasing recognition of this condition and consequently a greater requirement for knowledge of diagnostic procedures and treatment directions. Currently there is limited research into the conservative management of posterior instability, although it is recommended as first-line treatment prior to surgical review, particularly in those with an atraumatic instability mechanism. The aim of this paper is to outline a comprehensive rehabilitation program for the conservative management of posterior instability with a focus on scapular and humeral head control. The information provided includes extensive written information, flowcharts, figures and a table of management parameters that will provide therapists with adequate detail to replicate the program in the clinical setting.

Evidence-Based Review of Clinical Diagnostic Tests and Predictive Clinical Tests That Evaluate Response to Conservative Rehabilitation for Posterior Glenohumeral Instability: A Systematic Review

Context:

Posterior glenohumeral instability is poorly understood and can be challenging to recognize and evaluate. Using evidence-based clinical and predictive tests can assist clinicians in appropriate assessment and management.

Objective:

To review evidence-based clinical diagnostic tests for posterior glenohumeral instability and predictive tests that identify responders to conservative management.

Data Sources:

A comprehensive electronic bibliographic search was conducted using Embase, Ovid MEDLINE, PEDro, and CINAHL databases from their date of inception to February 2017.

Study Selection:

Studies were included for further review if they (1) reported on clinical diagnostic tests for posterior or posteroinferior instability of the glenohumeral joint, (2) assessed predictive clinical tests for posterior instability of the glenohumeral joint, and (3) were in English.

Study Design:

Systematic review.

Level of Evidence:

Level 4.

Data Extraction:

Data were extracted from the studies by 2 independent reviewers and included patient demographics and characteristics, index/reference test details (name and description of test), findings, and data available to calculate psychometric properties.

Results:

Five diagnostic and 2 predictive studies were selected for review. There was weak evidence for the use of the jerk test, Kim test, posterior impingement sign, and O’Brien test as stand-alone clinical tests for identifying posterior instability. Additionally, there was weak evidence to support the use of the painless jerk test and the hand squeeze sign as predictive tests for responders to conservative management. These findings are attributed to study design limitations, including small and/or nonrepresentative samples.

Conclusion:

Clustering of thorough history and physical examination findings, including the aforementioned tests, may identify those with posterior glenohumeral instability and assist in developing management strategies.

Recurrent Labral Tearing on Magnetic Resonance Imaging Is Not Predictive of Diminished Participation Among National Football League Athletes

PURPOSE

To investigate the prevalence of shoulder labral repair and utility of magnetic resonance imaging (MRI) in determining the risks of recurrent labral tearing and impact on future participation in the National Football League (NFL).

METHODS

Athletes invited to the NFL Combine between 2012 and 2015 were retrospectively reviewed. Athletes with a history of labral repair and MRI of the operative shoulder at the Combine were included in the study for further analysis, excluding athletes without a history of labral repair, labral repair without MRI at the Combine, additional procedure to the operative shoulder, or athletes still undergoing rehabilitation at the time of the Combine after labral repair. All MRIs were reviewed to determine initial labral repair location, the presence of recurrent tearing, and any concomitant shoulder pathology. Prospective information on future NFL participation in regard to draft status, games played, and games started in the athlete's first NFL season after the Combine was compared between athletes with a history of labral repair with and without recurrent tearing versus all other athletes participating in the Combine.

RESULTS

A total of 132 (10.1%) athletes underwent 146 shoulder labral repair procedures before the NFL Combine, of whom 32% (n = 39 athletes, n = 46 shoulders) had recurrent labral tears on MRI. Athletes with recurrent tears were more likely to have undergone bilateral labral repairs (P = .048) and possess concomitant shoulder pathology (P < .001). Recurrent labral tearing was significantly more common in the posterior labrum in athletes with a history of posterior labral repairs (P = .032). Prospective participation in the NFL in terms of games played (P = .38) or started (P = .98) was not significantly reduced in athletes with a history of labral repair compared with those without repair. Participation was not diminished in athletes with recurrent labral tears compared with those with intact repairs or those with evidence of degenerative joint disease.

CONCLUSIONS

Athletes invited to the NFL Scouting Combine with a history of bilateral repair, posterior labral repair, and concomitant shoulder pathology are at high risk of recurrent labral tearing on MRI. No significant reduction in NFL participation the year after the Combine was seen in athletes with a history of labral repair, recurrent labral tearing, or degenerative joint disease who were successfully drafted into the NFL. In athletes with a history of labral repair, assessment of labral integrity on MRI alone is not predictive of future short-term participation.

LEVEL OF EVIDENCE

Level IV, prognostic study-case series.

Epidemiology of Posterior Glenohumeral Instability in a Young Athletic Population

BACKGROUND

While several studies have observed the incidence of posterior glenohumeral instability in selected populations, there are no data from large-scale population-based studies with corresponding athletic exposure data to calculate incidence rates (IRs) and associated risk factors.

PURPOSE

To determine risk factors for posterior glenohumeral instability within the physically active population at the United States Military Academy.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

A longitudinal cohort study was performed over a 6-year period from 2006 to 2012 at the United States Military Academy utilizing the Cadet Illness and Injury Tracking System. Exposure data were collected from daily attendance data documented for every practice and game at the intramural, club, or varsity sport level. The primary outcomes calculated were the IRs of posterior glenohumeral joint instability per 1000 person-years at risk and per 1000 athlete-exposures. IR ratios and confidence intervals were calculated between male and female cadets and between intercollegiate and intramural athletes.

RESULTS

Between 2006 and 2012, there were 1348 shoulder injuries in total, with 633 instability events. During the study period, 113 posterior shoulder instability injuries (17.9% of instability events) and 26,408 person-years at risk were documented, for an overall IR of 4.28 per 1000 person-years. The overall IR of posterior instability was 0.08 per 1000 athlete exposures. In male athletes, 105 sustained a posterior shoulder instability event, for an IR of 4.67 per 1000 person-years. Female athletes were less likely to sustain a posterior instability event, accounting for only 8 events, for an IR of 2.04 per 1000 person-years. A total of 6670 athletes were at risk for posterior shoulder instability injury during the study period. A total of 55 injuries were documented, for an IR of 8.25 per 1000 person-years. Intercollegiate wrestlers had the highest IR: 34.15 per 1000 person-years. The sport with the highest injury rate among intramural sports was football, at 2.79 per 1000 person-years. Three athletes had a history of a posterior shoulder dislocation, while no significant difference was found for subluxation versus pain as the presenting symptom. Of the 113 posterior shoulder instability injuries, 77.0% required surgical stabilization. All injuries associated with weight lifting required surgical stabilization.

CONCLUSION

Among athletes, intercollegiate athletes are at an increased risk of posterior glenohumeral instability when compared with intramural athletes. Intercollegiate athletes and weight lifters demonstrate a high likelihood of requiring surgical treatment as compared with intramural athletes.

Painful posterior shoulder instability: Anticipating and preventing failure. A study in 25 patients

BACKGROUND

Painful posterior shoulder instability (PPSI) is the least common of the three clinical patterns of posterior shoulder instability. PPSI is defined as pain combined with anatomical evidence of posterior instability but no instability events.

MATERIAL AND METHOD

We studied a multicentre cohort of 25 patients with PPSI; 23 were identified retrospectively and had a follow-up of at least 2 years and 2 patients were included prospectively. Most patients engaged in sports.

RESULTS

All 25 patients underwent surgery, which usually consisted in arthroscopic capsulo-labral reconstruction. The outcome was excellent in 43% of patients; another 43% had improvements but reported persistent pain. The pain remained unchanged or worsened in the remaining 14% of patients. Causes of failure consisted of a missed diagnosis of shoulder osteoarthritis with posterior subluxation, technical errors, and postoperative complications. The main cause of incomplete improvement with persistent pain was presence of cartilage damage.

CONCLUSION

Outcomes were excellent in patients who were free of cartilage damage, bony abnormalities associated with posterior instability (reverse Hill-Sachs lesion, erosion or fracture of the posterior glenoid), technical errors, and postoperative complications.

Posterior shoulder instability: Prospective non-randomised comparison of operative and non-operative treatment in 51 patients

BACKGROUND

The management of posterior shoulder instability remains controversial. Consequently, for a symposium on this topic, the French Arthroscopy Society (SFA) conducted a prospective multicentre study comparing outcomes of operative and non-operative treatment.

OBJECTIVE

To compare outcomes after operative versus non-operative treatment of posterior shoulder instability.

HYPOTHESIS

The surgical treatment of posterior shoulder instability may achieve better clinical outcomes than non-operative treatment in selected patients.

MATERIAL AND METHODS

Fifty-one patients were included prospectively then followed-up for 12months. Three groups were defined based on the clinical presentation: recurrent dislocation or subluxation, involuntary instability or voluntary instability that had become involuntary, and shoulder pain with instability. Of the 51 patients, 19 received non-operative therapy involving a three-step rehabilitation programme and 32 underwent surgery with a posterior bone block, labral repair and/orcapsule tightening, or bone defect filling. At inclusion and at last follow-up, the Subjective Shoulder Value (SSV), Rowe score, Walch-Duplay score, and Constant score were determined.

RESULTS

The preliminary results after the first 12 months are reported here. In the non-operative and operative groups, the Constant score was 78 versus 87, the Rowe score 64 versus 88, and the Walch-Duplay score 69 versus 82, respectively. These differences were statistically significant (P<0.05).

DISCUSSION

To our knowledge, this study is the first comparison of non-operative versus operative treatment in a cohort of patients with documented posterior shoulder instability. Outcomes were better with operative treatment. However, this finding remains preliminary given the short follow-up of only 1 year.

LEVEL OF EVIDENCE

III, case-control study.

The Posterior Unstable Shoulder: Natural History, Clinical Evaluation and Imaging

Background:

There is a low incidence of posterior instability which is present in only 2% to 10% of all unstable shoulders. The posterior instable shoulder includes different manifestations like fixed dislocation, recurrent subluxation or dislocation.

Methods:

Research and online content related to posterior instability is reviewed. Natural history, clinical evaluation and imaging are described.

Results:

An awareness of the disorder, together with a thoughtful evaluation, beginning with the clinical history, usually leads to proper diagnosis. An appropriate physical exam, taking in account hyperlaxity and specific tests for posterior instability should be done.

Conclusion:

Posterior shoulder instability is an uncommon condition and is challenging to diagnose. There is not a single injury that is responsible for all cases of recurrent shoulder dislocation or subluxation, and the presence of soft tissue lesions or bone alterations should be evaluated, with the use of adequate simple radiology and multiplanar imaging.

Pitch-side management of acute shoulder dislocations: a conceptual review

The shoulder, specifically the glenohumeral joint, by virtue of its anatomical characteristics and biomechanics confers a large range of movement, which ultimately results in a joint that is inherently prone to becoming unstable. The incidence of acute traumatic shoulder dislocation varies within the sporting environment, commonly occurring following direct trauma. Anterior dislocations account for nearly 90% of all dislocations. While most are referred and managed in the emergency department, pitch-side relocation by experienced clinicians does occur prior to referral. The aim of this study was to delineate a guideline specifically for the pitch-side management of this common injury. A literature search of PubMed and Medline using the keywords ‘prehospital’, ‘pitch-side’, ‘shoulder dislocation’ and ‘reduction’ or ‘relocation technique’ was performed, and the available literature was reviewed and collated. Articles focusing on reduction techniques were then reviewed, with particular consideration on their applicability to a pitch-side setting. While studies exist that compare and contrast examination and reduction techniques, most are based in a hospital setting. To date, there is no standardised management protocol published for the initial management of an anterior dislocated shoulder in a pitch-side setting. This article addresses this discrepancy and proposes a structured, algorithmic approach to the pitch-side management of a shoulder dislocation. The article addresses factors to consider in a pitch-side setting, suitable techniques and postreduction care. While a systematic approach has been delineated in this article, we recommend those pitch-side medical practitioners who provide this form of support should have attended appropriate training and ensure adequate malpractice cover.

Treatment of The Posterior Unstable Shoulder

BACKGROUND

It is estimated that approximately 5% of glenohumeral instabilities are posterior. There are a number of controversies regarding therapeutic approaches for these patients.

METHODS

We analyse the main surgery alternatives for the treatment of the posterior shoulder instability. We did a research of the publications related with posterior glenohumeral instability.

RESULTS

There are conservative and surgical treatment options. Conservative treatment has positive results in most patients, with around 65 to 80% of cases showing recurrent posterior dislocation. There are multiple surgical techniques, both open and arthroscopic, for the treatment of posterior glenohumeral instability. There are procedures that aim to repair bone defects and others that aim to repair soft tissues and capsulolabral injuries. The treatment should be planned according to each case on an individual basis according to the patient characteristics and the injury type. Surgical treatment is indicated in patients with functional limitations arising from instability and/or pain that have not improved with rehabilitation treatment. The indications for arthroscopic treatment are recurrent posterior subluxation caused by injury of the labrum or the capsulolabral complex; recurrent posterior subluxation caused by capsuloligamentous laxity or capsular redundancy; and multidirectional instability with posterior instability as a primary component. Arthroscopic assessment will help identify potential injuries associated with posterior instability such as bone lesions or defects and lesions or defects of soft tissues. The main indications for open surgery would be in cases of Hill Sachs lesions or broad reverse Bankart lesions not accessible by arthroscopy. We indicated non-anatomical techniques (McLaughlin or its modifications) for reverse Hill-Sachs lesions with impairment of the articular surface between 20% and 50%. Disimpaction of the fracture and placement of bone graft (allograft or autograft) is a suitable treatment for acute lesions that do not exceed 50% of the articular surface and with articular cartilage in good condition. Reconstruction with allograft may be useful in lesions affecting up to 50% of the humeral surface and should be considered when there is a situation of non-viable cartilage at the fracture site. For defects greater than 50% of the articular surface or in the case of dislocations over 6 months in duration where there is poor bone quality, some authors advocate substitution techniques as a treatment of choice. The main techniques for treating glenoid bone defects are posterior bone block and posterior opening osteotomy of the glenoid.

CONCLUSIONS

The treatment of the posterior glenohumeral instability has to be individualized based on the patient´s injuries, medical history, clinical exam and goals. The most important complications in the treatment of posterior glenohumeral instability are recurrent instability, avascular necrosis and osteoarthritis.

Evaluation of Shoulder-Stabilizing Braces: Can We Prevent Shoulder Labrum Injury in Collegiate Offensive Linemen?

Background:

Shoulder injuries remain one of the most common injuries among collegiate football athletes. Offensive linemen in particular are prone to posterior labral pathology.

Purpose:

To evaluate the efficacy of shoulder bracing in collegiate offensive linemen with respect to injury prevention, severity, and lost playing time.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Offensive linemen at a single collegiate institution wore bilateral shoulder-stabilizing braces for every contact practice and game beginning in the spring of 2013. Between spring of 2007 and fall of 2012, offensive linemen did not wear any shoulder braces. Player injury data were collected for all contact practices and games throughout these time periods to highlight differences with brace use.

Results:

Forty-five offensive linemen (90 shoulders) participated in spring and fall college football seasons between 2007 and 2015. There were 145 complete offensive linemen seasons over the course of the study. Offensive linemen not wearing shoulder braces completed 87 seasons; offensive linemen wearing shoulder braces completed 58 seasons. Posterior labral tear injury rates were calculated for players who wore the shoulder braces (0.71 per 1000 athlete-exposures) compared with shoulders of players who did not wear the braces (1.90 per 1000 athlete-exposures). The risk ratio was 0.46 (95% CI, 0.16-1.30; P = .14). Mean time (contact practices and games) missed due to injury was significant, favoring less time missed by players who used braces (8.7 vs 36.60 contact practices and games missed due to injury; P = .0019). No significant difference in shoulder labral tears requiring surgery was found for brace use compared with no brace use.

Conclusion:

Shoulder-stabilizing braces were shown not to prevent posterior labral tears among collegiate offensive lineman, although they were associated with less time lost to injury. The results of this study have clinical significance, indicating that wearing a shoulder brace provides a protective factor for offensive linemen.

Evidence-based conservative rehabilitation for posterior glenohumeral instability: A systematic review

STUDY DESIGN

Systematic review.

OBJECTIVES

To identify the best evidenced-based approach for the conservative rehabilitation of patients with posterior glenohumeral instability.

BACKGROUND

Posterior glenohumeral instability is more common than previously thought. Proper management is imperative to control symptoms and maximize function.

METHODS

We conducted an electronic search, up to November 2014, for English-language studies involving rehabilitation of posterior shoulder instability. A manual search of reference lists of included articles and previously published reviews was also performed.

RESULTS

Five studies met the review inclusion criteria. Most studies demonstrated that rotator cuff and posterior deltoid strengthening could reduce instability recurrence and pain, and increase function, mainly in those with atraumatic posterior instability without previous surgery. These studies were mainly case series or retrospective designs.

CONCLUSIONS

Rotator cuff and posterior deltoid strengthening may help with symptom-management and functioning in those with posterior glenohumeral instability. Further research is needed to detect statistically significant outcomes from conservative treatment.

LEVEL OF EVIDENCE

Therapy, Level 3.