• RNA sequencing
• biomarker
• glenohumeral
• labral tear
• shoulder instability
• transcriptomics

• Geneva Foundation

• military
• posterior labral repair
• revision posterior labral repair
• revision posterior shoulder stabilization

• Posterior instability
• arthroscopic stabilization
• arthroscopy
• shoulder arthroscopy
• shoulder instability
• unidirectional instability

• Humans
• Arthroscopy/methods
• Joint Instability/surgery
• Shoulder Joint/surgery
• Treatment Outcome

• Kouvalchouk
• Posterior shoulder instability
• dislocation
• distal tibial allograft
• humeral head translation
• instability
• shoulder

• Humans
• Cadaver
• Shoulder Joint/surgery
• Shoulder Joint/physiopathology
• Joint Instability/surgery
• Allografts
• Tibia/surgery
• Male
• Deltoid Muscle/surgery
• Female
• Bone Transplantation/methods
• Aged
• Middle Aged
• Acromion/surgery

• Failure
• Posterior shoulder instability
• Revision

• Humans
• Shoulder Joint/surgery
• Shoulder Joint/physiopathology
• Joint Instability/surgery
• Reoperation
• Osteotomy/methods
• Treatment Failure
• Arthroscopy/methods
• Recurrence

• acromial morphology
• magnetic resonance imaging
• posterior shoulder instability
• shoulder instability

• Humans
• Acromion/diagnostic imaging
• Acromion/surgery
• Joint Instability/diagnostic imaging
• Joint Instability/surgery
• Shoulder Joint/diagnostic imaging
• Shoulder Joint/surgery
• Shoulder
• Cross-Sectional Studies
• Magnetic Resonance Imaging/methods
• Arthroscopy/methods

• Arthroscopy
• Capsulolabral
• Posterior acromial height
• Posterior labral repair
• Posterior labrum tear
• Pushups
• Shoulder surgery

• general sports trauma
• glenoid labrum
• instability
• shoulder

• labral repair
• military
• posterior shoulder instability
• shoulder instability

• Arthrography
• Diagnosis, Differential
• Humans
• Humerus/diagnostic imaging
• Humerus/injuries
• Joint Instability/etiology
• Ligaments, Articular/diagnostic imaging
• Ligaments, Articular/injuries
• Magnetic Resonance Imaging
• Pain/etiology
• Shoulder Joint/diagnostic imaging

There is no widespread consensus on the surgical treatment of posterior shoulder instability with critical posterior glenoid bone loss.

That opening posterior glenoid wedge osteotomy with soft tissue repair would improve the resistance forces of instability when compared with soft tissue repair alone in the setting of 20% critical bone lose.

Controlled laboratory study.

Native glenoid retroversion was measured on 9 shoulders using computed tomography (CT) scans. The humerus was potted in 90° of forward flexion and 30° of internal rotation relative to the scapula, and a posterior dislocation was performed to create a posterior capsulolabral injury model. The specimens were each taken through a fixed sequence of testing: (1) posteroinferior capsulolabral tear, (2) no glenoid bone loss with posteroinferior capsulolabral repair, (3) 20% posterior glenoid bone loss with posteroinferior capsulolabral repair, and (4) 20% glenoid bone loss with posterior glenoid opening wedge osteotomy and posteroinferior capsulolabral repair. Bone loss was created using a sagittal saw. The resultant peak forces with 1 cm of posterior translation were measured. A 1-way repeated-measures analysis of variance was used to compare mean force values.

After the initial dislocation event, all shoulders had a resultant posterior capsulolabral injury. The resulting labral injury was extended from 6- to 9-o’clock in all specimens to homogenize the extent of injury. Repairing the capsulolabral complex in the 20% posterior glenoid bone loss group did not result in a statistically significant increase in resistance force compared with the labral deficient group (34.1 vs 22.2 N; P = .068). When 20% posterior bone loss was created, the posterior glenoid osteotomy with capsulolabral repair was significantly stronger (43.8 N) than the posterior repair alone both with (34.1 N) and without (31.8 N) bone loss (P = .008 and .045, respectively).

In the setting of critical posterior glenoid bone loss, an opening wedge posterior glenoid osteotomy with capsulolabral repair improved resistance to posterior humeral translation significantly compared with capsulolabral repair alone.

The results of this biomechanical cadaveric study may aid in surgical planning for this complex patient population.

The purpose of this study was to validate glenoid cartilage lesions as a negative prognostic factor and to define a new image-based preoperative evaluation method to identify surgical candidates for arthroscopic labral refixation with suture anchors in posterior shoulder instability.

Twenty-six patients who underwent arthroscopic posterior labral repair for shoulder instability were evaluated. Only patients with structural dynamic posterior instability were included. We evaluated on preoperative magnetic resonance arthrogram: glenoid version, humeral head subluxation, type of capsular insertion, and the cartilage lesions using the new Cartilage Wear Index (CWI). Two subgroups were analyzed with regard to the preoperative CWI and shoulder outcome scores: Single Assessment Numerical Evaluation (SANE) and Western Ontario Shoulder Instability Index (WOSI).

The median age at operation was 28 (interquartile range = 21-33) years. Median overall postoperative outcome assessment demonstrated a SANE of 90 and a WOSI of 385. The median CWI was 1.02. Subgroup analysis revealed worse median WOSI and SANE scores in patients with a CWI >1.02 and a strong correlation between a high preoperative CWI and a higher postoperative WOSI score (R = 0.58; P = .038).

The CWI can be useful to identify patients who might obtain better outcomes when treated with arthroscopic labral repair in posterior shoulder instability.

• Instability
• anterior
• disability
• nonoperative
• operative
• posterior

• arthroscopic posterior shoulder instability repair
• critical posterior shoulder bone loss
• posterior shoulder instability
• revision posterior shoulder instability
• risk factors for posterior shoulder instability failure

The glenohumeral joint is one of the most frequently dislocated joints in the body, particularly in young, active adults.

To conduct a systematic review and meta-analysis to evaluate and compare outcomes between anterior versus posterior shoulder instability.

Systematic review; Level of evidence, 4.

A systematic review was performed using the PubMed, Cochrane Library, and MEDLINE databases (from inception to September 2019) according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were included if they were published in the English language, contained outcomes after anterior or posterior shoulder instability, had at least 1 year of follow-up, and included arthroscopic soft tissue labral repair of either anterior or posterior instability. Outcomes including return-to-sport (RTS) rate, postoperative instability rate, and pre- and postoperative American Shoulder and Elbow Surgeons (ASES) scores were recorded and analyzed.

Overall, 39 studies were included (2077 patients; 1716 male patients and 361 female patients). Patients with anterior instability had a mean age of 23.45 ± 5.40 years (range, 11-72 years), while patients with posterior instability had a mean age of 23.08 ± 8.41 years (range, 13-61 years). The percentage of male patients with anterior instability was significantly higher than that of female patients (odds ratio [OR], 1.36; 95% CI, 1.04-1.77; P = .021). Compared with patients with posterior instability, those with anterior instability were significantly more likely to RTS (OR, 2.31; 95% CI, 1.76-3.04; P < .001), and they were significantly more likely to have postoperative instability (OR, 1.53; 95% CI, 1.07-2.23; P = .018). Patients with anterior instability also had significantly higher ASES scores than those with posterior instability (difference in means, 6.74; 95% CI, 4.71-8.77; P < .001). There were no significant differences found in postoperative complications between the anterior group (11 complications; 1.8%) and the posterior group (3 complications; 1.6%) (OR, 1.12; 95% CI, 0.29-6.30; P = .999).

Patients with anterior shoulder instability had higher RTS rates but were more likely to have postoperative instability compared with posterior instability patients. Overall, male patients were significantly more likely to have anterior shoulder instability, while female patients were significantly more likely to have posterior shoulder instability.

• Bankart repair
• anterior labral tear
• anterior shoulder dislocation
• anterior shoulder instability
• posterior labral tear
• posterior shoulder dislocation
• posterior shoulder instability

• Arthroscopy
• Bankart
• Dislocation
• Glenohumeral
• Hill-Sachs
• Instability
• Latarjet
• Remplissage
• Shoulder
• Subluxation

• Arthroscopy
• Posterior instability
• Shoulder

• glenoid bone loss
• glenoid retroversion
• labral tear
• posterior shoulder instability

• arthroscopy
• instability
• posterior
• shoulder
• soft-tissue and bony abnormalities

• Arthroscopy/adverse effects
• Arthroscopy/methods
• Humans
• Joint Instability/complications
• Joint Instability/surgery
• Shoulder Dislocation/etiology
• Shoulder Dislocation/prevention & control
• Shoulder Joint/physiopathology
• Shoulder Joint/surgery

• FEDS classification
• PROs
• Shoulder
• dislocation
• instability
• subluxation

The Latarjet procedure is an established and popular procedure for recurrent anterior shoulder instability; however, to our knowledge, few studies have reported on the outcomes of revision for failed Latarjet surgery. We reviewed the causes and management of recurrent instability after previous Latarjet stabilization surgery. The outcomes of revision surgery were also evaluated.

A retrospective analysis of prospective data in patients undergoing revision surgery after failed Latarjet stabilization was conducted. Data were collected over a 5-year period and included patient demographics, clinical presentation, cause of recurrent instability, indications for revision surgery, intraoperative analysis, outcomes of revision surgery, and return to sport.

We identified 16 patients (12 male and 4 female patients) who underwent revision surgery for recurrent instability after Latarjet stabilization. Of these patients, 11 were athletes: 9 professional and 2 amateur athletes. The mean age at revision was 29.9 ± 8.9 years (range, 17-50 years). The indications for revision were anterior instability in 11 patients, posterior instability in 4, and both anterior and posterior instability in 1. Of the anterior instability cases, 54.5% were due to coracoid nonunion and 36.4% were due to capsular failure (retear). All posterior instability cases had posterior capsulolabral injuries, and the mean Beighton score in this group was 6 or higher. One patient had a failed Latarjet procedure with coracoid nonunion and a posterior labral tear.

Coracoid nonunion was the most common cause of recurrence after Latarjet stabilization, requiring an Eden-Hybinette procedure. The patients who returned with posterior instability had a high incidence of hypermobility and could be treated successfully by arthroscopic techniques.

• Latarjet
• anterior
• instability
• posterior
• revision
• stabilization

Circumferential tears of the glenohumeral labrum are an uncommon injury, comprising 2.4% of all labral lesions. Currently, the clinical outcomes of arthroscopic circumferential labral repair for patients with instability and combined anterior, posterior, and superior labral tears are not well-known.

Patients treated with arthroscopic circumferential shoulder labral repairs will have inferior clinical outcomes and higher failure rates compared with patients who have isolated arthroscopic anterior labral repairs.

Cohort study; Level of evidence, 3.

A retrospective cohort study was performed to identify patients aged 18 years and older who underwent circumferential arthroscopic stabilization for recurrent instability as compared with an age-matched control group of arthroscopic primary anterior labral repairs. Age at surgery, American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment Form score, Simple Shoulder Test (SST) score, 12-Item Short Form Health Survey (SF-12) score (mental and physical), and overall patient satisfaction with surgery were assessed for each group.

A total of 35 consecutive patients (36 shoulders) who underwent an arthroscopic 360° circumferential labral repair were compared with a matched group of 31 patients who underwent an isolated arthroscopic anterior labral repair. The mean follow-up period was 34.3 and 56.8 months, respectively. No significant difference was found between the 2 groups for overall satisfaction with the surgery or recurrent instability. At the time of the follow-up survey, 22% of the patients experienced pain and 25% of the patients experienced instability in the circumferential repair group, whereas 15% of the patients experienced some level of pain and 30% of patients experienced a subjective sense of subtle instability in the isolated repair group. The ASES scores were 87.3 in the combined labral repair group and 93.3 in the isolated anterior group (P = .35), SST scores were 10.7 and 11.3 (P = .70), SF-12 mental scores were 54.6 and 56.8 (P = .80), SF-12 physical scores were 53.2 and 54.2 (P = .98), and age at time of the surgery was 26.7 and 24.6 years (P = .33), respectively. There was no difference between the 2 groups in pre- and postoperative range of motion (P > .05).

There was no difference in shoulder stability and function in patients after 360° combined labral repairs versus anterior labral repair alone. With proper patient selection, patients can expect similar outcomes despite the more extensive surgical procedure and complex postoperative rehabilitation protocol for circumferential repairs.

• instability
• multidirectional
• outcomes
• repair
• shoulder

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.

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.

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).

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.

• Posterior glenohumeral instability
• arthroscopic
• dislocation
• history of surgery
• shoulder
• shoulder stabilization
• stabilization
• subluxation

• anterior instability
• outcomes
• posterior instability
• shoulder instability

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.

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

Systematic review; Level of evidence, 4.

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).

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.

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.

• arthroscopic
• arthroscopic surgery
• beach chair
• lateral decubitus
• posterior shoulder instability

• Arthroscopy/methods
• Humans
• Joint Instability/surgery
• Patient Positioning
• Patient Satisfaction
• Peripheral Nerve Injuries/etiology
• Postoperative Complications/etiology
• Shoulder Joint/surgery

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

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.

Cohort study; Level of evidence, 3.

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.

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.

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.

• NFL
• football
• performance
• posterior labrum
• shoulder

• athlete
• epidemiology
• injury prevention
• instability
• labrum
• posterior instability
• shoulder instability

• Shoulder instability
• arthroscopy
• glenoid dysplasia
• labral tear
• posterior instability
• retroversion

• Capsulolabral reconstruction
• Posterior
• Shoulder instability

Posterior shoulder instability is a rare clinical condition that encompasses different degrees of severity including various possible pathologies involving the labrum, capsule, bony lesions, and even locked posterior dislocation. When focusing on soft tissue involvement, the diagnosis of posterior instability may be difficult to make because frequently patients report vague symptoms not associated with a clear history of traumatic shoulder dislocation. Pathological soft tissue conditions associated with posterior instability in most cases are related to posterior labral tear and/or posterior capsular detensioning/tear. The diagnosis can be facilitated by physical examination using specific clinical tests (i. e., jerk test, Kim test, and reinterpreted O’Brien test) together with appropriate imaging studies (i. e., magnetic resonance arthrography). Arthroscopy may help in a complete evaluation of the joint and allows for the treatment of soft tissue lesions in posterior instability. Caution is warranted in the case of concomitant posterior glenoid chondral defect as a potential cause of poor outcome after soft tissue repair in posterior instability.

• Arthroscopy
• Glenohumeral joint
• Joint instability
• Shoulder dislocation
• Soft tissue injuries

• Adult
• Arthroscopy/methods
• Female
• Humans
• Male
• Middle Aged
• Ontario
• Reoperation
• Retrospective Studies
• Shoulder/surgery
• Shoulder Joint/surgery
• Treatment Outcome
• Wound Healing/physiology

• instability
• posterior stabilization
• shoulder arthroscopy

• Bone loss
• Dislocation
• Instability
• Posterior
• Reverse Hill–Sachs
• Shoulder

Posterior instability of the shoulder is becoming an increasingly recognized shoulder injury in the athletic population. Diagnostic elements, such as etiology, directionality, and degree of instability are essential factors to assess in the unstable athletic shoulder. Concomitant injuries and associated pathologic lesions continue to be a significant challenge in the surgical management of posterior shoulder instability. Return to sport and previous level of play is ultimately the goal for every committed athlete and surgeon, thus subpopulations of athletes should be recognized as distinct entities requiring unique diagnostic, functional outcome measures, and surgical approaches.

• Posterior shoulder instability
• Overhead throwing athletes
• Contact athletes

• glenohumeral version
• magnetic resonance imaging
• posterior humeral avulsion of the glenohumeral ligament
• posterior shoulder instability