A 4-portal arthroscopic stabilization in posterior shoulder instability

Posterior Shoulder Instability in Tennis Players: Aetiology, Classification, Assessment and Management

Background

Micro-traumatic posterior shoulder instability (PSI) is an often missed and misdiagnosed pathology presenting in tennis players. The aetiology of micro-traumatic PSI in tennis players is multifactorial, including congenital factors, loss of strength and motor control, and sport-specific repetitive microtrauma. Repetitive forces placed on the dominant shoulder, particularly combinations of flexion, horizontal adduction, and internal rotation contribute to the microtrauma. These positions are characteristic for kick serves, backhand volleys, and the follow-through phase of forehands and serves. The aim of this clinical commentary is to present an overview of the aetiology, classification, clinical presentation, and treatment of micro-traumatic PSI, with a particular focus on tennis players.

Level of Evidence

5.

Return to Sport After Surgical Management of Posterior Shoulder Instability: A Systematic Review and Meta-analysis

BACKGROUND

Posterior shoulder instability accounts for a small proportion of all shoulder instability, although it can affect athletes of all types, from contact to overhead athletes. Surgical treatment is quite successful in these patients; however, the literature reports a wide range of rates of return to sport.

PURPOSE/HYPOTHESIS

The purpose was to determine the return-to-sport rates after surgical stabilization for posterior shoulder instability. It was hypothesized that patients would experience a high rate of return to sport.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

Embase, PubMed, and MEDLINE were searched for relevant literature from database inception until April 2020, and studies were screened by 2 reviewers independently and in duplicate for studies reporting rates of return to sport after surgical management of posterior shoulder instability. Demographic data as well as data on return to sport and functional outcomes were recorded. A meta-analysis of proportions was used to combine the rates of return to sport using a random effects model. A risk of bias was assessed for all included studies.

RESULTS

Overall, 32 studies met inclusion criteria and comprised 1100 patients (1153 shoulders) with a mean age of 22.8 years (range, 11-65) and a mean follow-up of 43.2 months (range, 10-228). The pooled rate of return to any level of sport was 88% (95% CI, 84%-92%; I² = 68.7%). In addition, the pooled rate of return to the preinjury level was 68% (95% CI, 60%-76%; I² = 79%). Moreover, the pooled return-to-sport rate for contact athletes was 94% (95% CI, 90%-97%; I² = 0%), while for throwing athletes it was 88% (95% CI, 83%-92%; I² = 0%).

CONCLUSION

Surgical management of posterior shoulder instability resulted in a high rate of return to sport, as well as significant pain reduction and functional improvement in most patients. However, only two-thirds of athletes can return to their preinjury levels of sport.

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.

Return to sport after surgical treatment for posterior shoulder instability: a systematic review

Purpose

To report the rate of return to sport after surgical treatment for posterior shoulder instability among athletes.

Methods

A systematic review of the literature regarding rate of return to sport after surgical treatment for posterior shoulder instability was undertaken. The primary outcome measure was return to sport. The secondary outcome measures included rate of return to sport to preinjury level, time to return to sport, injury type, reoperations after primary surgery, and objective patient-reported outcome data. Data is summarized with ranges and tables.

Results

A total of 23 studies met inclusion criteria. The rate of return to sport ranged from 57.9%-100%. The rate of return to sport to the preinjury level ranged from 47.4%-100%. Time to return to sport ranged from 4.3-7.7 months. Furthermore, 66% of subjects had an acute traumatic injury and 34% were of insidious onset. The most commonly reported outcome measures were American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores and visual analog scale (VAS) pain scores. At a minimum of 1-year follow-up, ASES and VAS pain scores improved. Revision rates ranged from 0%-36.8%.

Conclusion

The systematic review demonstrated high rates of return to sport and relatively high rates of return to preinjury level of sport among all athletes who underwent surgical treatment for posterior shoulder instability. Objective patient-reported outcome metrics improved postoperatively whereas revision rates remained low.

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.

Arthroscopic treatment of posterior instability of the shoulder with an associated reverse Hill-Sachs lesion using an iliac bone-block autograft

Posterior dislocation of the shoulder is often accompanied by an impression fracture in the anterior surface of the humeral head, called a reverse Hill-Sachs injury. This bone defect can engage on the posterior glenoid rim, which can lead to recurrent instability and progressive joint destruction. We describe a new arthroscopic procedure that fills the reverse Hill-Sachs lesion with an iliac bone-block autograft and repairs the posterior articular capsule arthroscopically, which can stabilize the posterior shoulder. It avoids the need to detach the subscapularis tendon and can reduce the risks associated with open procedures. LEVEL OF EVIDENCE: V, technical note.

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.

Patient Positioning in Arthroscopic Management of Posterior-Inferior Shoulder Instability: A Systematic Review Comparing Beach Chair and Lateral Decubitus Approaches

PURPOSE

To analyze the available literature pertaining to clinical outcomes and complications of posterior-inferior shoulder stabilization performed arthroscopically in either the beach chair (BC) or lateral decubitus (LD) position.

METHODS

According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 3 databases (PubMed, EMBASE, and Medline) were searched up to January 2018 for English-language studies on posterior shoulder instability. Descriptive statistics are presented. The Methodological Index for Non-Randomized Studies (MINORS) scale was used to assess quality.

RESULTS

Twenty-five studies were included, examining 1,085 patients (n = 140 BC; n = 945 LD), of mean age 25.0 years, 27.1% female, and mean 3.1 years of follow-up. MINORS scores for BC and LD were 11.2 and 9.8, respectively. Regardless of positioning, patients did not differ across numerous outcomes and various surgical factors (e.g., number of portals, anchors, anchor types, concomitant pathology, or postoperative rehabilitation protocol). Postoperative patient satisfaction ranged from 85% to 87.5% and 93% to 100% for patients treated in BC and LD positions, respectively. Although not reported for BC, overall and preinjury return-to-play (RTP) rates in LD patients ranged from 72% to 100% and 55% to 100%, respectively, returning from 3 to 7.6 months postoperatively. Failure rates in the BC and LD positions ranged from 0% to 9.4% and 0% to 29%, respectively. There were no differences in reported incidences of neuropraxia, stroke, nonfatal pulmonary embolus, vision loss, cardiac arrest, or other positioning-related complications.

CONCLUSIONS

Arthroscopic management of posterior-inferior shoulder instability has a successful track record and minimal complication profile. Although patient positioning appears to influence results, with those treated in the LD position experiencing marginally higher patient satisfaction and failure rates, the current data prevent any conclusions being made regarding the superiority of one approach over another. As the clinical relevance of patient positioning remains to be determined, larger, higher-level study designs with long-term follow-up are required.

LEVEL OF EVIDENCE

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

Posterior Shoulder Instability

Posterior shoulder instability is a relatively uncommon condition, occurring in ∼10% of those with shoulder instability. Because of the rarity of the condition and the lack of knowledge in treatment, it is often misdiagnosed or patients experience a delay in diagnosis. Posterior instability typically affects athletes participating in contact or overhead sports and is usually the result of repetitive microtrauma or blunt force with the shoulder in the provocative position of flexion, adduction, and internal rotation, leading to recurrent subluxation events. Acute traumatic posterior dislocations are rare injuries with an incidence rate of 1.1 per 100,000 person years. This rate is ∼20 times lower than that of anterior shoulder dislocations. Risk factors for recurrent instability are: (1) age below 40 at time of first instability; (2) dislocation during a seizure; (3) a large reverse Hill-Sachs lesion; and (4) glenoid retroversion. A firm understanding of the pathoanatomy, along with pertinent clinical and diagnostic modalities is required to accurately diagnosis and manage this condition.

Bone loss in patients with posterior gleno-humeral instability: a systematic review

PURPOSE

The aim of this systematic review was to analyse outcomes of surgical procedures for glenoid and/or humeral bony defects, performed singularly or in combination, in patients with posterior gleno-humeral instability. A secondary aim was to establish in clinical settings which percentage of glenoid or humeral bone loss should be treated with a bony procedure to avoid recurrence of dislocation.

METHODS

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 was performed using various combinations of the keywords "shoulder", "posterior instability", "dislocation", "bone loss", "reversed bony Bankart", "osseous glenoid defects", "glenoid bone grafting", "glenoid", "humeral head", "surgery", "gleno-humeral", "reversed Hill-Sachs", over the years 1966-2014. Data were independently extracted by all the investigators: demographics, previous surgery, imaging assessment, bone defect measurement, diagnosis, surgical management, return to sport, complications, and outcome measurements. The outcome parameters were recurrence of dislocation and clinical scores.

RESULTS

Nineteen articles, describing patients with glenoid bony defects, humeral bony defects, or both in the setting of posterior gleno-humeral instability were included. A total of 328 shoulders in 321 patients were included, with a median age at surgery of 33.4 years, ranging from 14 to 79 years. Patients were assessed at a median follow-up period of 3.6 years (ranging from 8 months to 22 years). A redislocation event occurred in 32 (10 %) shoulders. The redislocation event occurred in 2 (10 %) of 20 shoulders with glenoid bony defect and in 12 (11 %) of 114 shoulders with humeral bony defect.

CONCLUSION

Even though the general principle of treating recognized glenoid and humeral bone defects in patients with posterior gleno-humeral instability is widely accepted, to date few studies in the literature accurately establish which bone defects should be treated with bony procedures and the exact correlation between percentage of bone loss and higher risk of redislocation in clinical settings. A limitation to the present systematic review is the small number of included patients, due to the rare entity of posterior bone defects/reversed Hill-Sachs. The clinical relevance is that the results of this systematic review can be helpful to guide clinicians in the management of patients with posterior gleno-humeral instability and glenoid and/or humeral bony defects. This manuscript also highlights the need for accurate description of results in further investigations. The main drawback of the available articles in the topic is that they rarely clarify the percentage of bone loss in patients undergoing a redislocation event.

LEVEL OF EVIDENCE

IV.

Posterior shoulder instability in the athletic population: Variations in assessment, clinical outcomes, and return to sport

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.

Triple labrum tears repaired with the JuggerKnot™ soft anchor: Technique and results

Purpose:

The 2-year outcomes of patients undergoing repair of triple labrum tears using an all-suture anchor device were assessed.

Materials and Methods:

Eighteen patients (17 male, one female; mean age 36.4 years, range: 14.2-62.3 years) with triple labrum tears underwent arthroscopic repair using the 1.4 mm JuggerKnot Soft Anchor (mean number of anchors 11.5, range: 9-19 anchors). Five patients had prior surgeries performed on their operative shoulder. Patients were followed for a mean of 2.0 years (range: 1.6-3.0 years). Constant–Murley shoulder score (CS) and Flexilevel scale of shoulder function (FLEX-SF) scores were measured, with preoperative and final postoperative mean scores compared with a paired Student's t-test (P < 0.05). Magnetic resonance imaging (MRI) was also performed at final postoperative.

Results:

Overall total CS and FLEX-SF scores increased from 52.9 ± 20.4 to 84.3 ± 10.7 (P < 0.0001) and from 29.3 ± 4.7 to 42.0 ± 7.3 (P < 0.0001), respectively. When divided into two groups by whether or not glenohumeral arthrosis was present at the time of surgery (n = 9 each group), significant improvements in CS and FLEX-SF were obtained for both groups (P < 0.0015). There were no intraoperative complications. All patients, including contact athletes, returned to their preinjury level of sports activity and were satisfied. MRI evaluation revealed no instances of subchondral cyst formation or tunnel expansion. Anchor tracts appeared to heal with fibrous tissue, complete bony healing, or combined fibro-osseous healing.

Conclusion:

Our results are encouraging, demonstrating a consistent healing of the anchor tunnels through arthroscopic treatment of complex labrum lesions with a completely suture-based implant. It further demonstrates a meaningful improvement in patient outcomes, a predictable return to activity, and a high rate of patient satisfaction.

Level of Evidence:

Level IV case series.

Posterior Instability of the Shoulder: A Systematic Review and Meta-analysis of Clinical Outcomes

BACKGROUND

To date, there are no reports in the literature of a systematic review and meta-analysis for posterior instability of the shoulder.

PURPOSE

The primary objective was to systematically capture, critically evaluate, and perform a meta-analysis of all available literature on arthroscopic clinical outcomes to provide insight and clinical recommendations for unilateral posterior shoulder instability. The secondary objective was to use the same means to assess clinical outcome literature for open treatment, of which a subset of highly reported outcome measures were used to determine superiority of arthroscopic versus open procedures for unilateral posterior shoulder.

STUDY DESIGN

Systematic review, meta-analysis.

METHODS

A systematic search to obtain every available, published, level of evidence study reporting patient data for unidirectional posterior shoulder instability was performed by use of the Cochrane Database of Systematic Reviews, PubMed/Medline database, manual searches of high impact factor journals and conference proceedings, and secondary references appraised for studies meeting inclusion criteria.

RESULTS

The systematic search captured a total of 1035 publications. After initial exclusion criteria were applied, 607 abstracts were assessed for eligibility. Full-text articles were obtained for 324 articles, and a total of 53 unique publications (27 arthroscopic studies, 26 open studies) reporting clinical outcomes for unidirectional posterior shoulder instability met inclusion criteria and were included in the systematic review and meta-analysis.

CONCLUSION

Well-defined and uniform shoulder outcome measures to assess posterior shoulder instability are lacking throughout the literature. However, arthroscopic procedures are shown to be an effective and reliable treatment for unidirectional posterior glenohumeral instability with respect to outcome scores, patient satisfaction, and return to play. Despite similar results of outcome measures to the overall athletic population, throwing athletes are less likely to return to their preinjury levels of sport compared with contact athletes or the overall athletic population. Evidence also indicates that arthroscopic stabilization procedures using suture anchors result in fewer recurrences and revisions than anchorless repairs in young adults engaging in highly demanding physical activity. Furthermore, the literature suggests that patients treated arthroscopically have superior outcomes compared with patients who undergo open procedures with respect to stability, recurrence of instability, patient satisfaction, return to sport, and return to previous level of play.

Arthroscopic Posterior Stabilization of the Shoulder Using a Percutaneous Knotless Mattress Suture Technique

Posterior shoulder instability is far less common than anterior instability, and its arthroscopic treatment can be technically demanding. We describe a percutaneous arthroscopic technique for posterior shoulder stabilization using mattress sutures and knotless anchors. Spinal needles are used to pass the sutures percutaneously in a mattress fashion. Knotless anchors are used to secure the sutures under the labrum. These anchors can be used without cannulas, giving easier access to the posterior glenoid. This procedure is simple, cost-effective, and safe, avoiding the presence of both knots and suture strands in contact with the humeral head.

Arthroscopic posterior labral repair and capsular shift with a lateralized posterior portal

Arthroscopic techniques for posterior shoulder subluxation with labral injuries in athletes have shown good results. The difficulty with the procedure is gaining appropriate access to the posteroinferior quadrant of the glenoid at a steep enough angle that allows for safe anchor placement. Various portals have been described that can be used as accessory portals for anchor placement. Although the use of additional portals to create appropriate access to the joint is always encouraged, preoperative planning can minimize the need for their use. The video shows a simple technique for posterior labral repair with capsular plications through a lateralized posterior portal in the lateral decubitus position. This technique allows the surgeon to address posterior labral tears and capsular laxity without the need for accessory portals.

Modified arthroscopic McLaughlin procedure for treatment of posterior instability of the shoulder with an associated reverse Hill-Sachs lesion

Traumatic posterior shoulder dislocations are often accompanied by an impression fracture on the anterior surface of the humeral head known as a "reverse Hill-Sachs lesion". This bony defect can engage on the posterior glenoid rim and subsequently lead to recurrent instability and progressive joint destruction. We describe a new modified arthroscopic McLaughlin procedure, which allows for filling of the bony defect with the subscapularis tendon and subsequently prevents recurrence of posterior instability. This technique creates a double-mattress suture providing a large footprint for the subscapularis and a broader surface area to allow for effective tendon to bone healing. Furthermore, it obviates the need for detaching the subscapularis tendon and avoids the morbidity potentially associated with open procedures. Level of evidence V.

Posterior instability of the shoulder: diagnosis and management

Recurrent posterior instability of the shoulder can be difficult to diagnose and technically challenging to treat. Although not as common as anterior instability, recurrent posterior shoulder instability is prevalent among certain demographic and sporting groups, and may be overlooked if one is not aware of the typical examination and radiographic findings. The diagnosis itself can be difficult as patients typically present with vague or confusing symptoms, and treatment has evolved from open to arthroscopic surgical techniques. This article is intended to review the anatomy and biomechanics associated with posterior shoulder instability, to discuss the pathogenesis and presentation of posterior instability, and to describe the variety of treatment options and clinical results.

Arthroscopic stabilization of posterior shoulder instability

Posterior shoulder instability is a rare and challenging condition with a complex patho-anatomy. The role of arthroscopic repair in the treatment remains poorly defined. The purpose of this study is to evaluate the result of arthroscopic stabilization procedures in patients with posterior shoulder instability. In this case series, we treated eighteen patients (19 shoulders) with posterior shoulder instability with either arthroscopic thermal capsular shrinkage (9 patients), capsulorrhaphy (3) or labral refixation (7). There were eight male and ten female patients with a mean age of 26 years. The study group included unidirectional (6 patients; PI), bi-directional (8; PII) and multidirectional posterior instability (5; MDI). The Rowe-score and DASH-score as well as subjective and objective evaluations of the patients function, range of motion, pain and instability were used as clinical outcome measurements. At a mean follow-up of 50 months, the Rowe-score improved significantly from 46 to 74 (P = 0.005). Four patients (21%) had recurrent instability after arthroscopic treatment (2 with generalized ligamentous laxity; 3 after thermal shrinkage). Analysis of postoperative DASH-scores showed a tendency toward inferior outcomes after thermal shrinkage and in patients with an a-traumatic origin of shoulder instability. We conclude that arthroscopic shoulder stabilization by either labral refixation or capsulorrhaphy is a safe and effective treatment for posterior shoulder instability. Thermal capsular shrinkage however showed poor results and should be abandoned for this indication.

Arthroscopic posterior stabilization and anterior capsular plication for recurrent posterior glenohumeral instability

PURPOSE

The purpose of this study was to evaluate the outcomes and identify predictors of success for arthroscopic posterior Bankart reconstruction with modern suture anchor repair and anterior capsulolabral plication in a well-defined patient population-recurrent, traumatic, involuntary, unidirectional posterior shoulder instability.

METHODS

Patients with recurrent, traumatic, involuntary, unidirectional posterior shoulder instability who underwent arthroscopic repair with a minimum of 2 years' follow-up were identified and evaluated retrospectively with outcome measures in the form of objective and subjective scores. Statistical analysis was performed to identify predictors of success with significance set at .05.

RESULTS

Twenty-nine consecutive patients with a mean age of 26.3 years underwent posterior reconstruction and anterior balancing capsulolabral plication as needed with a mean follow-up of 5.5 years. Outcome scores averaged as follows: American Shoulder and Elbow Surgeons, 90.7; University of California, Los Angeles, 32.6; Simple Shoulder Test, 11.7; and Western Ontario Shoulder Instability, 82.9% of normal. Recurrent instability occurred in 3.4% of patients, 84.6% returned to sports, and 96.6% of patients believed surgery was successful and worthwhile. Patients who were younger (<30 years) or patients with more extensive pathology who required additional surgical procedures or received supplemental anterior plication sutures had less reliable or worse outcomes (P < or = .041).

CONCLUSIONS

In a traumatic patient population with involuntary, unidirectional posterior shoulder instability, modern suture anchor repair of posterior labral lesions is effective and provides reliable outcomes. Younger patients and patients with worse pathology who required additional procedures had less reliable outcomes. Patients with supplemental anterior plication had more postoperative pain, and this adjunctive procedure may not be necessary for traumatic posterior labral tear surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Arthroscopic management of posterior instability

In comparison with anterior shoulder instability, posterior instability is uncommon, occurring in 2% to 10% of cases, and covering a wide clinical spectrum ranging from locked posterior dislocation to the often subclinical recurrent posterior subluxation (RPS). With increased clinical awareness, imaging advances such as magnetic resonance arthrography, and the development of specific provocative physical examination tests, the identification of RPS in the athletic population is improving. This article describes the anatomic-based arthroscopic approach to treatment of RPS, which allows for enhanced identification and repair of intra-articular pathology including posterior capsular laxity, complete or incomplete detachment of the posterior capsulolabral complex, and inferior capsular tears. While postoperative results are generally good to excellent after stabilization for RPS, there is room for improvement.

[Open and arthroscopic procedures for posterior shoulder instability]

Posterior instability is less common than anterior shoulder instability and diagnosis and treatment are more difficult and complex. This review article gives an overview on diagnostics, classification and the influence on therapy. Furthermore different arthroscopic and open procedures are presented and the surgical techniques are described in detail.

The addition of rotator interval closure after arthroscopic repair of either anterior or posterior shoulder instability: effect on glenohumeral translation and range of motion

BACKGROUND

Although the use of rotator interval closure is frequently advocated as a useful supplement to shoulder instability repairs, the addition of a rotator interval closure after arthroscopic instability repair has not been fully investigated.

PURPOSE

The objective of this study was to investigate whether a rotator interval closure improves glenohumeral stability in an anterior and posterior instability shoulder model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fourteen fresh-frozen cadaveric shoulder specimens were dissected free of soft tissues, leaving the rotator cuff intact with simulated cuff loading. All specimens were mounted in a custom testing apparatus using infrared sensors to document glenohumeral translation and rotation. The specimens were then tested for stability in the following order: vented/subluxated state, after arthroscopic anterior (Group 1; 7 specimens) or posterior (Group 2; 7 specimens) instability repair with suture anchors, and then after rotator interval closure. For each of the 3 testing conditions, the following were measured: (1) external and internal rotation at neutral, (2) external and internal rotation at 90 degrees of abduction, (3) posterior and anterior translation at neutral rotation (15 N and 25 N), (4) anterior translation at 90 degrees of abduction and external rotation (Group 1; 15 N and 25 N), (5) posterior translation at 90 degrees of flexion and internal rotation (Group 2; 15 N and 25 N), and (6) sulcus testing in neutral (7.5 N).

RESULTS

Posterior stability was only improved after anchor capsulolabral repair (8.0 to 5.0 mm; P = .017, 25 N), but there was no improvement after rotator interval closure (5.0 to 4.6 mm; P = .453). However, anterior stability was improved after capsulolabral repair (8.6 to 4.0 mm; P = .016, 25 N) and also improved further by rotator interval closure (4.0 to 2.4 mm; P = .007). The mean loss of external rotation was significantly increased by the addition of the rotator interval closure in both neutral and abducted glenohumeral positions, with a mean external rotation loss of 28 degrees in neutral (P = .013). The addition of a rotator interval closure did not improve sulcus stability (P = .4).

CONCLUSION

The addition of an arthroscopic rotator interval closure after posterior capsulolabral repair did not improve posterior stability; however, anterior stability was improved further after a rotator interval closure. Inferior stability was not improved. Arthroscopic rotator interval closure significantly decreased external rotation at both neutral and abducted arm positions.

CLINICAL RELEVANCE

Arthroscopic closure may be beneficial in certain cases of anterior shoulder instability; however, posterior instability was not improved. Predictable losses of external rotation after rotator interval closure are of concern.

Arthroscopic fixation of the subscapularis tendon in the reverse Hill-Sachs lesion for traumatic unidirectional posterior dislocation of the shoulder

Posterior unidirectional instability of the shoulder following trauma is frequently associated with a cartilage-bone defect on the anterior joint surface of the humeral head. This defect can catch on the posterior joint surface during internal rotation of the arm, which causes redislocation of the humeral head in a posterior direction, thus increasing joint destruction. We describe a new arthroscopic surgical technique in which the subscapularis tendon is mobilized and attached to the defect using nonabsorbable or bioabsorbable suture anchors. In an manner analogous to open surgery with arthrotomy and transposition of the subscapularis tendon insertion into the defect, this arthroscopic technique fills up the defect, blocks extension during internal rotation of the arm, and safely avoids redislocation of the humeral head in a dorsal direction. The arthroscopic technique we describe is easy and safe to perform. Complicated tightening of the posterior joint capsule is no longer necessary following acute injury.

Thermal capsulorrhaphy for isolated posterior instability of the glenohumeral joint without labral detachment

BACKGROUND

Posterior instability of the glenohumeral joint is uncommon, and a minimally invasive, technically easy method of treatment with consistent results has not been reported.

HYPOTHESIS

Thermal capsulorrhaphy for posterior instability with a period of postoperative immobilization will satisfactorily reestablish shoulder stability.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 15 shoulders (13 patients) with isolated posterior instability without labral detachment were treated with thermal capsulorrhaphy. Eleven shoulders were immobilized for 6 weeks after surgery; 14 shoulders were clinically evaluated at a mean of 36 months (range, 26-53 months) after surgery. Of these patients, 2 (3 shoulders) had declined postoperative immobilization.

RESULTS

Eleven shoulders were rated as excellent or good, and 3 experienced recurrent instability and were considered failures. The 3 failures occurred in 1 of 11 shoulders that were immobilized and 2 of 3 (in the same patient) that were not immobilized postoperatively.

CONCLUSION

Thermal capsulorrhaphy for posterior instability of the glenohumeral joint, followed by 6 weeks of postoperative immobilization, restored glenohumeral stability in this group of patients.

Arthroscopic labral repair and capsular shift of the glenohumeral joint: technical pearls for a multiple pleated plication through a single working portal

The arthroscopic treatment of shoulder instability is becoming increasingly popular with recent clinical studies showing similar success rates comparable to open procedures. These improved success rates are likely due to a better understanding of the pathoanatomy of shoulder instability and addressing all injured structures including labral tears and capsular injury and stretching. I present a new arthroscopic technique for shoulder stabilization that makes use of already known techniques by sequentially repairing the labral tear and performing a capsular shift through multiple, separate pleated plications through a single working portal. This technique allows for an anatomic labral repair with a capsular shift as large as desired by performing as many additional tucks of capsule for plication as needed, comparable to open techniques with less surrounding tissue trauma. This technique is actually easier than more traditional arthroscopic methods, and the multiple pleats may provide a load-sharing effect dispersed through each pleat, which may decrease the risk of load failure.

Recurrent posterior shoulder instability

Recurrent posterior shoulder instability is an uncommon, debilitating condition in young adults that is being diagnosed with increasing frequency. Although a number of predisposing factors have been identified, their relative importance remains poorly understood. Poor results have been reported following operative intervention to treat recurrent posterior instability with nonanatomic techniques. The more recent development of lesion-specific surgery has improved clinical results, particularly when that surgery has been performed arthroscopically. Operative treatment is therefore being increasingly recommended at an earlier stage to patients who do not respond to supervised rehabilitation programs.