Biomechanics of posterior shoulder instability - current knowledge and literature review

Comprehensive Evaluation and Arthroscopic Management of Circumferential Labral Tears Following Traumatic First Time Shoulder Dislocation: A Case Report and Review

Introduction

Pan-labral tears, commonly associated with recurrent shoulder dislocations, are a well-documented pathology. However, circumferential pan-labral tears following a first-time shoulder dislocation represent a rare and scarcely reported entity in the literature. Accurate diagnosis requires a comprehensive clinical history, physical examination, and further evaluation, often involving MRI. Even with advanced imaging, the acute nature of the injury can lead to the oversight of pan-labral tears, necessitating arthroscopic assessment for definitive diagnosis. Repairing such extensive glenoid labral tears presents a challenging task, requiring skilled surgeons to utilize accessory portals and percutaneous techniques for optimal visualization and anchor placement trajectory. To the best of our knowledge, this case report represents the first documentation of a pan-labral tear associated with a 1st-time shoulder dislocation.

Case Report

A 27-year-old Asian male presented with pain and limited range of motion in the left shoulder following a single episode of anterior shoulder dislocation during cricket. Initial X-rays were unremarkable, but subsequent MRI revealed an anteroinferior labral tear with intact rotator cuffs. Arthroscopic evaluation disclosed a pan-labral tear, prompting meticulous repair under general and locoregional anesthesia. The patient achieved full recovery postoperatively.

Conclusion

While pan-labral tears are typically linked to recurrent dislocations, this case underscores their occurrence in a 1st-time traumatic shoulder dislocation without overt clinical signs or fractures. Arthroscopic repair demands careful intraoperative planning to achieve optimal tensioning and alignment of labral and capsular tissues. This report contributes to the limited literature on pan-labral tears associated with initial shoulder dislocations, emphasizing the importance of arthroscopic evaluation for accurate diagnosis and successful repair.

From Diagnosis to Decision-Making: A Systematic Review of the Management of Reverse Hill-Sachs Lesions after Posterior Shoulder Dislocations

(1) Background: The aim of this study is to describe all of the possible surgical procedures that intend to treat the McLaughlin lesion (or Reverse Hill-Sachs) in posterior shoulder dislocation. (2) Methods: Google Scholar, Pubmed, and Embase were used as databases in our research. Studies reporting the results of posterior shoulder dislocations surgically treated with procedures addressing the humeral lesion were evaluated. The studies reporting results after fracture-dislocation and multidirectional instability were excluded. (3) Results: A total of 16 studies were included in our review for a total of 207 shoulders with a mean age of 41.7 years that were evaluated at a mean of 62.1 months. The Modified McLaughlin procedure and the Graft procedures were the most commonly performed. No statistically significant difference was found between the two at the evaluation of the clinical score. (4) Conclusions: Our review highlights the importance of a correct diagnosis and an accurate surgical treatment choice based on the surgeon's experience and on the patients' characteristics.

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.

Does glenoid bone loss accompany posterior shoulder instability with only labral tear? A magnetic resonance imaging-based study

BACKGROUND

The primary aim of this study was to investigate bone loss in the glenoid with magnetic resonance imaging in posterior shoulder instability with only a labral tear.

METHODS

A total of 76 patients operated on because of posterior and anteroposterior shoulder instability only with a labral tear between 2006 and 2019 (n = 40 and n = 36, respectively) were included in this study. The instability type, a presence of an additional superior labrum anteroposterior (SLAP) lesion, the number of dislocations, and the magnetic resonance imaging-based measurements (the glenoid diameter and the bone defect size in the glenoid, the Hill-Sachs lesion [HSL] and the reverse HSL [rHSL] length, the angle and the arc length of HSL and rHSL, and the humerus head diameter and its area) were analyzed.

RESULTS

The size of the anterior glenoid defect, the rHSL measurements (length, angle, and arc length), and the ratio of the anterior glenoid defect size to the glenoid diameter were significantly higher for anteroposterior instability (P < .01) cases. There was no significant difference (P = .49, .64, and .82, respectively) for the presence of an additional SLAP pathology, the glenoid diameter, the posterior glenoid defect, and the ratio of the posterior glenoid defect size to the glenoid diameter in posterior and anteroposterior instability groups. The increased number of dislocations was associated with increased rHSL length and total arc length (P = .04 and .03, respectively). An additional SLAP lesion in posterior shoulder instabilities was not associated with the bone defect size (P = .29).

CONCLUSION

Although the posterior shoulder instability with only a labral tear is likely to cause a bone defect, we have shown that the instability is not expected to be caused by the bone defect. Therefore, this study points out that only soft tissue repair without considering the bone defect could be promising in this patient group.

Arthroscopic Posterior Capsulolabral Repair With Suture-First Versus Anchor-First Technique in Patients With Posterior Shoulder Instability (Type B2): Clinical Midterm Follow-up

Background

Isolated soft tissue injuries of the posterior capsulolabral complex can be addressed arthroscopically, with various anchor systems available for repair.

Purpose

To evaluate clinical and patient-reported outcomes after arthroscopic capsulolabral repair in patients with posterior shoulder instability (PSI) and to compare differences in outcomes between patients treated with a suture-first technique (PushLock anchor) and an anchor-first technique (FiberTak all-suture anchor).

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 32 patients with dynamic structural PSI (type B2 according to the ABC classification) treated with an arthroscopic posterior capsulolabral repair. After a mean follow-up time of 4.8 ± 3.4 years (range, 2-11) patients were evaluated clinically, and standardized outcome scores were obtained for the Subjective Shoulder Value (SSV), the Western Ontario Shoulder Instability Index (WOSI), Rowe, Kerlan-Jobe Orthopaedic Clinic (KJOC), patient satisfaction (0-5 [best]), and pain on a visual analog scale (VAS; 0-10 [worst]).

Results

The overall satisfaction level with the outcome of the surgery was 4.6 ± 0.5 (range, 4-5). No patient suffered from instability events. The mean VAS level for pain was 0.4 ± 0.9 (range, 0-4) at rest and 1.9 ± 2.0 (range, 0-6) during motion. The mean SSV was 80 ± 17 (range, 30-100), the mean postoperative WOSI score 75% ± 19% (range, 18-98), the mean Rowe score 78 ± 20 (range, 10-100), and the mean KJOC score was 81 ± 18 (range, 40-100) for the entire cohort. There was no significant difference between the techniques with regard to range of motion, strength, or clinical outcome scores.

Conclusion

Arthroscopic posterior capsulolabral repair was a satisfactory method to treat structural PSI type B2 with regard to stability, pain relief, and functional restoration. The majority of patients had good outcomes. No differences in outcomes were observed between the anchor-first and suture-first techniques.

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

Traumatische posteriore Luxation als seltene Ursache einer multidirektionalen Schulterinstabilität im Profisport

Die multidirektionale Instabilität der Schulter als Folge einer traumatischen posterioren Luxation ist selten und in der Literatur nur unzureichend beschrieben. Hier präsentiert wird der Fall eines 28-jährigen Anschiebers aus dem deutschen Bob-Olympia-Kader, der eine weichteilige multidirektionale Instabilität in Folge einer traumatischen posterioren Luxation beim Mountainbiken erlitt. Die Stabilisierung des Schultergelenks erfolgte arthroskopisch mittels kombinierter anteriorer und posteriorer Labrumrefixation.

Common and Less Well-known Upper-limb Injuries in Elite Tennis Players

A recent increase in epidemiology studies on injuries in elite tennis players has helped to shed light on the types of injuries these athletes sustain. This article reviews the common upper-limb injuries in elite players and includes less well known, but important, injuries. A search was conducted to identify current relevant studies involving elite tennis players. Injury frequency rates, injuries by regions, and types of injuries together with a list of commonly reported injuries in the upper limb were established. This list was then reviewed and refined by a sports medicine physician who cares for elite tennis players to include both those injuries of the upper limb that are common and those that are less well known but still important and frequently encountered. Common injuries include internal shoulder impingement, rotator cuff pathology, labral tears, elbow tendinopathies, as well as extensor carpi ulnaris tendinopathies and subluxation. Posterior shoulder instability, distal humeral bone stress, elbow medial collateral ligament, and nondominant wrist ulnar collateral ligament injuries are not commonly reported injuries, but they are of significant clinical importance.

Posterior shoulder instability: a systematic review

INTRODUCTION

This review aims to provide information on outcomes of surgical procedures for soft tissue or bony glenoid and/or humeral abnormalities in case of posterior shoulder instability.

SOURCE OF DATA

A systematic review of the literature according to the PRISMA guidelines was performed. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase, Ovid and Google Scholar databases using various combinations of the keywords 'shoulder', 'posterior instability', 'dislocation', 'reversed bony bankart', 'reversed Hill Sachs', and 'capsulolabral' was performed.

AREAS OF AGREEMENT

A total of 847 shoulders in 810 patients were included. A redislocation event occurred in 33 (8.7%) of 411 shoulders with soft tissue abnormalities and in 12 (9.1%) of 132 shoulders with bony abnormalities of the glenoid, humeral head or both.

AREAS OF CONTROVERSY

The optimal treatment modalities for posterior shoulder dislocation remain to be defined.

GROWING POINTS

Operative stabilization for posterior shoulder instability should be lesion-specific and should correct all components of the posterior instability.

AREAS TIMELY FOR DEVELOPING RESEARCH

Future prospective studies should aim to establish the optimal treatment modalities for posterior shoulder instability.