Loss of chondrolabral containment of the glenohumeral joint in atraumatic posteroinferior multidirectional instability

Does glenoid version affect the post-operative clinical outcome after repair of posterior labral tear: A retrospective study

Introduction

Posterior shoulder instability and consequent labral tear have been predominantly associated with retroversion of the bony glenoid and chondrolabral version. However, literature concerning the degree of glenoid and chondrolabral version and clinical outcomes following labral repair is scarce.

Methods

A retrospective cohort study was undertaken among patients with posterior shoulder instability who had undergone arthroscopic isolated posterior labral repair. The MRI was used to assess the bony and labral variations of the glenoid using the Friedman method and further categorized as either anteverted or retroverted glenoid. American Shoulder and Elbow Surgeons (ASES), Oxford Shoulder Score (OSS), and Single Assessment Numeric Evaluation (SANE) scores were used to evaluate pre- and postoperative clinical outcomes at a minimum follow-up of one year.

Results

33 shoulder MRIs performed at our institution were available for radiographic analysis. Among the 33 shoulders that underwent posterior shoulder capsulolabral repair, 23 were available for clinical follow-up for at least one year (range, 12-108 months). The mean (±SD) labral version and bony version were -3.98 (±5.68) and -2.83 (±5.20), respectively. The mean (±SD) postoperative ASES, Oxford score, and SANE scores for all participants were 84.04 (±14.14), 43.38 (±3.81), and 78.57 (±17.40), respectively. However, the difference in clinical outcomes in patients with anteverted or retroverted glenoid versions was not statistically significant.

Conclusion

Our study concludes a strong correlation between posterior glenohumeral instability and higher degree of glenoid retroversion. Nevertheless, variations in the glenoid version appear to have no significant impact on clinical outcomes.

Level of study

Level IV, retrospective cohort.

Occult, Incomplete, and Complete Posterior Labral Tears Without Glenohumeral Instability on Imaging Underestimate Labral Detachment

PURPOSE

To introduce a classification of posterior labral tear and describe clinical characteristics, magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA) findings, arthroscopic findings, and outcomes after arthroscopic repair for patients with posterior labral tears without glenohumeral instability.

METHODS

Sixty patients with posterior labral tear who underwent arthroscopic repair were analyzed retrospectively. Patients with shoulder instability were excluded. Tear patterns were classified into 3 types; occult (type 1), incomplete (type 2), and complete (type 3) based on MRI/MRA studies. A visual analog scale score for pain, American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation score for satisfaction, and return to sports were evaluated at a minimum follow-up of 2 years. Computed tomography arthrography was performed at a year follow-up for assess labral healing. The diagnosis was confirmed in arthroscopy, and arthroscopic labral repair without capsular plication was performed.

RESULTS

The mean patient age was 30.4 ± 6.9 years, and all patients were male. Forty-four patients (73.3%) were participating in sports. MRI/MRA studies identified 10 patients with type 1, 18 with type 2, and 32 with type 3 tears. Type 1 tear patients showed a significantly longer symptom duration than those with type 3 (32.5 ± 17.2 vs 18.2 ± 17.1 months; P = .015). In arthroscopic findings, 70% of type 1 tear was confirmed as incomplete or complete tears. The American Shoulder and Elbow Surgeons score improved from 79.6 ± 10.3 to 98.1 ± 3.7, and pain was relieved from 2.4 ± 0.7 to 0.2 ± 0.5 at the last follow-up visit with high labral healing rate (95%). Thirty-nine (88.6%) patients returned to sports at preinjury levels.

CONCLUSIONS

In active young men with shoulder pain during daily activities or sports despite programmed conservative treatment, posterior labral tears should be considered even when MRI/MRA findings are ambiguous. Arthroscopic posterior labral repair without capsular plication provided satisfactory clinical outcomes and a high labral healing rate.

LEVEL OF EVIDENCE

Level Ⅳ, case series.

Pediatric and Adolescent Shoulder Instability

PURPOSE OF REVIEW

Traumatic and atraumatic shoulder instability is common in pediatric and adolescent patients. It is well-established that young patients with anterior shoulder dislocation are at high risk of recurrent instability. This review assesses the current literature pertaining to management of both anterior instability and MDI in the pediatric and adolescent populations.

RECENT FINDINGS

Current research suggests that pediatric and adolescent patients with shoulder instability have excellent outcomes following arthroscopic Bankart repair; however, higher rates of recurrent instability requiring revision surgical management have been identified in patients with more than one dislocation episode pre-operatively, those with Hill-Sachs lesions and those under age 16. The addition of the remplissage procedure to an arthroscopic Bankart repair may be useful in preventing recurrent instability for patients with large Hill-Sachs lesions. Open procedures with bony glenoid augmentation may be indicated in patients with significant glenoid bone loss, or those who have failed primary surgical management, with promising outcomes reported following the Latarjet coracoid process transfer procedure in the adolescent population. Pediatric and adolescent patients with hyperlaxity, and those participating in swimming or gymnastics are more likely to have multidirectional instability (MDI). Non-surgical management with physical therapy is the mainstay of treatment for MDI with positive outcomes reported overall. In young patients with MDI who continue to have symptoms of instability and pain that effects daily activities or sports despite an adequate and appropriate course of rehabilitation, surgical management with capsulorrhaphy may be considered, with promising outcomes reported for both open and arthroscopic techniques. Attentive selection of timing and surgical procedure for pediatric and adolescent patients with anterior shoulder instability may help to prevent recurrent instability following shoulder stabilization. Although most pediatric and adolescent patients with MDI do well following non-surgical management alone, those that fail conservative management have good outcomes following arthroscopic or open capsulorrhaphy.

Multidirectional instability of the shoulder: surgical techniques and clinical outcome

Multidirectional instability of the shoulder has a complex pathoanatomy. It is characterized by a redundant glenohumeral capsule and increased joint volume. Subtle clinical presentation, unclear trauma history and multifactorial etiology poseses a great challenge for orthopedic surgeons in terms of diagnosis. Generally accepted therapeutic approach is conservative and the majority of patients achieve good results with rehabilitation. In patients who are symptomatic despite appropriate rehabilitation, surgical intervention may be considered. Good results have been obtained with open inferior capsular surgery, which has historically been performed in these patients. In recent years, advanced arthroscopic techniques have taken place in this field, and similar results compared to open surgery have been obtained with the less-invasive arthroscopic capsular plication procedure.

Biomechanical Analysis of Posterior Open-Wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-Free, J-Shaped Iliac Crest Bone Graft

BACKGROUND

Posterior open-wedge osteotomy and glenoid reconstruction using a J-shaped iliac crest bone graft showed promising clinical results for the treatment of posterior instability with excessive glenoid retroversion and posteroinferior glenoid deficiency.

PURPOSE

To evaluate the biomechanical performance of the posterior J-shaped graft to restore glenoid retroversion and posteroinferior deficiency in a cadaveric shoulder instability model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A posterior glenoid open-wedge osteotomy was performed in 6 fresh-frozen shoulders, allowing the glenoid retroversion to be set at 0°, 10°, and 20°. At each of these 3 preset angles of glenoid retroversion, the following conditions were simulated: (1) intact joint, (2) posterior Bankart lesion, (3) 20% posteroinferior glenoid deficiency, and (4) posterior J-shaped graft (at 0° of retroversion). With the humerus in the Jerk position (60° of glenohumeral anteflexion, 60° of internal rotation), stability was evaluated by measuring posterior humeral head (HH) translation (in mm) and peak translational force (in N) to translate the HH over 25% of the glenoid width. Glenohumeral contact patterns were measured using pressure-sensitive sensors. Fixation of the posterior J-graft was analyzed by recording graft micromovements during 3000 cycles of 5-mm anteroposterior HH translations.

RESULTS

Reconstructing the glenoid with a posterior J-graft to 0° of retroversion significantly increased stability compared with a posterior Bankart lesion and posteroinferior glenoid deficiency in all 3 preset degrees of retroversion (P < .05). There was no significant difference in joint stability comparing the posterior J-graft with an intact joint at 0° of retroversion. The posterior J-graft restored mean contact area and contact pressure comparable with that of the intact condition with 0° of retroversion (222 vs 223 mm2, P = .980; and 0.450 vs 0.550 MPa, P = .203). The mean total graft displacement after 3000 cycles of loading was 43 ± 84 µm, and the mean maximal mediolateral graft bending was 508 ± 488 µm.

CONCLUSION

Biomechanical analysis of the posterior J-graft demonstrated reliable restoration of initial glenohumeral joint stability, normalization of contact patterns comparable with that of an intact shoulder joint with neutral retroversion, and secure initial graft fixation in the cadaveric model.

CLINICAL RELEVANCE

This study confirms that the posterior J-graft can restore stability and glenohumeral loading conditions comparable with those of an intact shoulder.

The Effect of Glenoid Version on Glenohumeral Instability

In recent years, an appreciation for the dynamic relationship between glenoid and humeral-sided bone loss and its importance to the pathomechanics of glenohumeral instability has substantially affected modern treatment algorithms. However, comparatively less attention has been paid to the influence of glenoid version on glenohumeral instability. Limited biomechanical data suggest that alterations in glenoid version may affect the forces necessary to destabilize the glenohumeral joint. However, this phenomenon has not been consistently corroborated by the results of clinical studies. Although increased glenoid retroversion may represent an independent risk factor for posterior glenohumeral instability, this relationship has not been reliably observed in the setting of anterior glenohumeral instability. Similarly, the effect of glenoid version on the failure rates of surgical stabilization procedures remains poorly understood.

Advances in the Non-Operative Management of Multidirectional Instability of the Glenohumeral Joint

Multidirectional instability (MDI) of the glenohumeral joint refers to symptomatic subluxations or dislocations in more than one direction. The aetiology of MDI is multifactorial, which makes the classification of this condition challenging. A shoulder rehabilitation program is the initial recommended treatment for MDI, however available rehabilitation programs have varying levels of evidence to support their effectiveness. In 2016, we published the details of an evidence-based program for MDI that has been evaluated for efficacy in two single-group studies and a randomised controlled trial. In 2017, we published a clinical commentary on the aetiology, classification, and treatment of this condition. The aim of this paper is to provide an update on the components of these publications with a particular focus on new advances in the non-operative management of this condition.

Clinical Outcomes, Survivorship, and Return to Sport After Arthroscopic Capsular Repair With Suture Anchors for Adolescent Multidirectional Shoulder Instability: Results at 6-Year Follow-up

Background:

Multidirectional shoulder instability (MDI) refractory to rehabilitation can be treated with arthroscopic capsulolabral reconstruction with suture anchors. To the best of our knowledge, no studies have reported on outcomes or examined the risk factors that contribute to poor outcomes in adolescent athletes.

Purpose:

To identify risk factors for surgical failure by comparing anatomic, clinical, and demographic variables in adolescents who underwent intervention for MDI.

Study Design:

Case series; Level of evidence, 4.

Methods:

All patients 20 years or younger who underwent arthroscopic shoulder surgery at a single institution between January 2009 and April 2017 were evaluated. MDI was defined by positive drive-through sign on arthroscopy plus positive sulcus sign and/or multidirectional laxity on anterior and posterior drawer tests while under anesthesia. A 2-year minimum follow-up was required, but those whose treatment failed earlier were also included. Demographic characteristics and intraoperative findings were recorded, as were scores on the Single Assessment Numeric Evaluation (SANE), Pediatric and Adolescent Shoulder Survey (PASS), and short version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH).

Results:

Overall, 42 adolescents (50 shoulders; 31 female, 19 male) were identified as having undergone surgical treatment for MDI with minimum 2-year follow-up or failure. The mean follow-up period was 6.3 years (range, 2.8-10.2 years). Surgical failure, defined as recurrence of subluxation and instability, was noted in 13 (26.0%) shoulders; all underwent reoperation at a mean of 1.9 years (range, 0.8-3.2 years). None of the anatomic, clinical, or demographic variables tested, or the presence of generalized ligamentous laxity, was associated with subjective outcomes or reoperation. Number of anchors used was not different between shoulders that failed and those that did not fail. Patients reported a mean SANE score of 83.3, PASS score of 85.0, and QuickDASH score of 6.8. Return to prior level of sport occurred in 56% of patients.

Conclusion:

Adolescent MDI refractory to nonsurgical management appeared to have long-term outcomes after surgical intervention that were comparable with outcomes of adolescent patients with unidirectional instability. In patients who experienced failure of capsulorrhaphy, results showed that failure most likely occurred within 3 years of the index surgical treatment.

A New Method for Measuring Glenoid Version on Standard Magnetic Resonance Imaging

Background

The most effective method and modality for measuring glenoid version for different shoulder conditions is uncertain. Computed tomography (CT) imaging exposes the patient to radiation, and standard magnetic resonance imaging (MRI) does not consistently image the entire scapula. This study investigates the reliability of a new method for assessing glenoid version using routine shoulder MRI.

Methods

MRI images of 20 patients undergoing arthroscopy for shoulder instability were independently assessed by 3 clinicians for osseous and chondrolabral glenoid version. To assess glenoid version, a line was drawn from medial corner of the glenoid body to midpoint of the glenoid face. A line perpendicular to this was the reference against which to measure glenoid version. Measurements were repeated after 3 months to assess intra- and interobserver reliability. Reliability was determined using intraclass correlation coefficients (ICCs).

Results

Interclass correlation coefficients showed at least good reliability for most estimates of intraobserver reliability (ICC ≥ .66) and excellent reliability for most estimates of interobserver reliability (ICC ≥ .84), with the exception of some inferior glenoid measurements where ICC was poor (ICC ≤.41).

Discussion

We propose that this new method of measuring glenoid on standard axial MRI can be used as a simple, practical, and reliable method in shoulder instability patients, which will reduce the requirement for CT in this group.

Posterior open wedge glenoid osteotomy provides reliable results in young patients with increased glenoid retroversion and posterior shoulder instability

PURPOSE

The relationship between posterior shoulder instability and increased glenoid retroversion has been documented. Posterior open wedge glenoid osteotomy is a possible treatment option for patients with increased glenoid retroversion, but outcomes in the literature are limited. Therefore, the purpose of this study was to report the clinical and radiological outcomes following posterior glenoid osteotomy.

METHODS

Patients that underwent posterior glenoid osteotomy for posterior shoulder instability with a GR angle of more than or equal to 10°, and were at least 12 months out from surgery, were included in the study. General data, medical history, and radiographic data such as the pre- and postoperative glenoid retroversion angle were extracted from the patients' hospital documentation notes. To evaluate the postoperative outcome, the Rowe standard rating scale for shoulder instability and the Oxford shoulder instability score were collected retrospectively.

RESULTS

A total of 12 shoulders (11 patients) could be included. The mean pre-operative glenoid retroversion was 23.3° (range 12°-35°) and this reduced significantly (p = 0.003) to a mean of 13° (range 1°-28°) postoperatively. At a mean follow-up of 19.8 months (range 14-36), the median Rowe score was 90 points (range 45-100 points) and the median Oxford instability score was 44 points (range 21-48 points). There were no postoperative re-dislocations or revision surgeries; however, one patient reported signs of recurrent shoulder instability and four asymptomatic glenoid neck fractures occurred.

CONCLUSION

Open wedge posterior glenoid osteotomy provides reliable clinical results with a low rate of clinical failure in a stringently selected patient cohort at short-term follow-up. However, due to the risk of potentially severe complications, we advocate this procedure for experienced shoulder surgeons only, who are familiar with its anatomical and technical considerations.

LEVEL OF EVIDENCE

IV (case series).

Editorial Commentary: Bone Loss in Shoulder Instability Occurs in 3 Dimensions

The continued debate regarding the appropriate threshold to consider performing bony stabilization procedures in the treatment of shoulder instability has contributed to a recent boom of new research in this area. The contribution of both glenoid bone loss and version in predicting potential clinical failure after soft tissue stabilization is one of those topics. The authors of the featured study demonstrate the relationship between measured glenoid version and bone loss, which can assist us in our clinical decision making. To date, most measures of glenoid version have been reported based on analysis of 2 dimensions. However, with 2-dimensional analysis, bone loss may result in potentially errant measurement of version and require subsequent correction. Moreover, 3-dimensional analysis could result in a more nuanced understanding of the complexities of glenoid pathologic study in patients with shoulder instability.

Multidirectional Shoulder Instability: Treatment

Background:

The treatment of multidirectional instability of the shoulder is complex. The surgeon should have a clear understanding of the role of hiperlaxity, anatomical variations, muscle misbalance and possible traumatic incidents in each patient.

Methods:

A review of the relevant literature was performed including indexed journals in English and Spanish. The review was focused in both surgical and conservative management of multidirectional shoulder instability.

Results:

Most patients with multidirectional instability will be best served with a period of conservative management with physical therapy; this should focus in restoring strength and balance of the dynamic stabilizers of the shoulder. The presence of a significant traumatic incident, anatomic alterations and psychological problems are widely considered to be poor prognostic factors for conservative treatment. Patients who do not show a favorable response after 3 months of conservative treatment seem to get no benefit from further physical therapy.

When conservative treatment fails, a surgical intervention is warranted. Both open capsular shift and arthroscopic capsular plication are considered to be the treatment of choice in these patients and have similar outcomes. Thermal or laser capsuloraphy is no longer recommended.

Conclusion:

Multidirectional instability is a complex problem. Conservative management with focus on strengthening and balancing of the dynamic shoulder stabilizers is the first alternative. Some patients will fare poorly and require either open or arthroscopic capsular plication.

Multidirectional Instability: Natural History and Evaluation

Background:

Multidirectional instability (MDI) represents a great challenge to the orthopedic surgeon. When treating these patients we must be aware that instability refers to a symptomatic situation, thus multidirectional instability is defined as symptomatic involuntary instability in two or more directions, and should be clearly differentiated from asymptomatic hyperlaxity.

It may be associated with hyperlaxity, either congenital or acquired following repetitive stress, but also may be present without hyperlaxity, which is rare.

Methods:

We searched in the online data bases and reviewed the relevant published literature available.

Results:

Many differences can be seen in the current literature when identifying these patients, unclear definitions and criteria to be included in this patient group are common.

Conclusion:

Understanding the complex shoulder biomechanics as well as being aware of the typical clinical features and the key examination signs, which we review in this article, is of paramount importance in order to identify and classify these patients, allowing the best treatment option to be offered to each patient.

Soft tissue-based surgical techniques for treatment of 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.

Osteochondral Autograft Transfer Technique for Glenoid Osteochondral Defect

Glenoid osteochondral defects can be a significant source of pain and disability in an active population. Many treatments are available, but most joint-preserving procedures are limited to debridement, abrasion chondroplasty, or marrow-stimulation techniques, all of which depend on healthy underlying bone and none of which address underlying bony pathology. Osteochondral autograft transfer has been a successful form of treatment for lesions in the knee, elbow, and ankle, especially when subchondral bone is involved. We describe an arthroscopic method of treating glenoid osteochondral lesions with an osteochondral autograft transfer using a graft from the patient's ipsilateral knee. This technique addresses both cartilage and osseous pathology with minimal morbidity and provides a good biological restorative option for patients with isolated glenoid osteochondral defects.

Posteroinferior shoulder instability: clinical outcome of arthroscopic stabilization in 32 shoulders and categorization based on labral mapping

INTRODUCTION

Posterior shoulder instability is rare, appears in varying clinical patterns and can be the main symptom in patients with instability in more than one direction. The purpose was to analyze and categorize our patients and to report on the results of operative treatment by arthroscopy.

MATERIALS AND METHODS

A consecutive series of 32 shoulders in 31 patients from a 7-year period was chosen for retrospective clinical evaluation with VAS for pain, Rowe Score, Constant Score and Simple Shoulder Test. Follow-up rate was 100 %, the mean FU period was 28 months (range 13-58). Allocation based on clinical and intraoperative criteria resulted in the 4 groups A to D characterized by an increasing traumatic impact. Patients received a posterior Bankart repair with bone anchors in 21 or capsular plication to the intact labrum in 11 cases.

RESULTS

The clinical outcome scores were generally good and all showed a trend towards better results from A to D, but without significance. Pain on VAS pre- and postoperatively showed a significant (p < 0.0001) overall decline from 7.4 to 1.8. The Rowe Score increased significantly (p < 0.0001) from a mean value of 41.4 to 89.5 points. Three patients were reoperated and satisfied, four patients (12.5 %) not satisfied at follow-up. The drive-through sign was significantly (p = 0.003) more distinct in the less traumatic groups A and B than groups C and D. Subgroup allocation resulted in the following distribution: 7 patients qualified for group A (PPM = predominantly posterior multidirectional), 13 for B (RPS = recurrent posterior subluxation), 7 for C (unidirectional) and 5 patients for group D (bi-directional). Graphic display of labral lesions, called "labral mapping", revealed typical patterns for the groups.

CONCLUSION

In patients with posteroinferior shoulder instability, good results can be obtained with the arthroscopic treatment of all identified pathologies. Categorization into one of four subgroups might be a valuable tool regarding the choice of the operative treatment options.

Arthroscopic and magnetic resonance arthrogram features of Kim's lesion in posterior shoulder instability

PURPOSE

The purpose of this study was to describe the anatomic features of the glenoid and labrum for shoulders with and without Kim's lesions, as well as define the sensitivity, specificity, and reliability of magnetic resonance arthrogram for the detection of these lesions and determine the interobserver reliability of Kim's classification for posterior labral tears.

METHODS

A retrospective, blinded analysis of 41 shoulders was performed. Twenty-one shoulders composed the Kim's lesion group. Three observers measured glenoid and chondrolabral retroversion and anterior and posterior labral height. The shoulders were classified as 1 of 3 types according to Kim's classification.

RESULTS

There were no differences in glenoid version, chondrolabral version, glenoid depth, and labral height between the groups. The sensitivity, specificity, positive predictive value, and negative predictive value for diagnosing Kim's lesions were 85.7%, 75%, 78.3%, and 83.3%, respectively. The κ values for interobserver reliability for detecting and classifying Kim's lesions were 0.739 (substantial) and 0.329 (fair), respectively.

CONCLUSIONS

Patients with incomplete posteroinferior labral tears have similar retroversion (bony and soft tissue) and labral height to patients without posterior shoulder instability. The sensitivity, specificity, and reliability of magnetic resonance arthrogram for detecting these lesions are substantial. The interobserver reliability of Kim's classification is fair.

LEVEL OF EVIDENCE

Level IV, retrospective case-control study.

Pediatric and adolescent shoulder instability

Instability of the shoulder is a common issue faced by sports medicine providers caring for pediatric and adolescent patients. A thorough history and physical examination can help distinguish traumatic instability from multidirectional or voluntary instability. A systematic understanding of the relevant imaging characteristics and individual patient disease and goals can help guide initial treatment. Given the high risk of recurrent instability, young, active patients who seek to return to competitive contact sports should consider arthroscopic stabilization after a first-time instability event. MDI should be treated initially with conservative rehabilitation. Patients who fail extensive conservative treatment may benefit from surgical stabilization. Arthroscopic techniques may now approach the results found from traditional open capsular shift procedures. Future studies should be designed to examine the outcomes in solely pediatric and adolescent populations after both conservative and operative treatment of shoulder instability.

Patient-reported outcomes following a physiotherapy rehabilitation programme for atraumatic posterior shoulder subluxation

BACKGROUND

There is a paucity of research that describes the patient-reported benefits of physiotherapy rehabilitation for atraumatic posterior instability despite non-operative treatment being considered the initial treatment of choice. This retrospective case series review describes the patient-reported outcomes following a physiotherapy rehabilitation programme for atraumatic posterior shoulder instability.

METHODS

Nineteen consecutive patients with a clinical diagnosis of atraumatic posterior shoulder subluxation completed our physiotherapy programme. All patients completed Oxford Instability Shoulder scores (OISS) and Western Ontario Shoulder Instability Index (WOSI) scores before and after physiotherapy intervention.

RESULTS

Patients reported a statistically significant clinical improvement in the main outcome measures following physiotherapy intervention. The OISS showed a mean improvement of 18.6 points, whereas the WOSI score showed a mean improvement of 37.2%. Following physiotherapy rehabilitation, all patients reported that their shoulder did not prevent them from performing their work/studies or their chosen hobbies/sports.

CONCLUSIONS

Our results support the view that specialized physiotherapy rehabilitation is a valuable treatment option for atraumatic posterior shoulder instability and reveal significant clinically important improvements in patient-reported outcomes.

Revision posterior shoulder stabilization

BACKGROUND

Revision arthroscopic posterior glenohumeral stabilization requires a thorough understanding of the static and dynamic stabilizers of the glenohumeral joint. The evaluation of these patients is complex but critical given the variety of possible underlying lesions.

METHOD

We reviewed the literature surrounding recurrent and revision posterior instability biomechanics, etiology, evaluation, treatment, and outcomes. We also reviewed our own database of posterior instability cases and isolated revision procedures to review our own outcomes and to highlight overall concepts.

DISCUSSION/CONCLUSION

Although other authors have argued that performing a revision procedure indicates for an open procedure and osseous augmentation, our experience has been that revision posterior stabilization arthroscopic soft-tissue repair alone may be indicated in selected patients. After identification of posterior glenoid bone loss/effective retroversion and mechanical failure of prior repairs, the majority of the patients with recurrence of posterior instability likely have either recurrent or persistent labral pathology or patulous capsules with occult multi-directional instability primarily manifesting in the posterior direction. These patients are best served with capsular shift, reefing, and plication, often requiring 180-270° repair and 4 or greater suture anchors. Because of significant heterogeneity in the clinical outcomes reported to date further research will be necessary to define the clinical outcomes in revision posterior stabilization.

Posterior shoulder instability in the contact athlete

Historically, posterior shoulder instability has been a challenging problem for contact athletes and orthopedic surgeons alike. A complete understanding of the normal shoulder anatomy and biomechanics and the pathoanatomy responsible for the instability is necessary for a successful clinical outcome. In addition, the surgeon must be familiar with the diagnostic imaging and physical examination maneuvers required for the correct diagnosis without missing any other concurrent abnormalities. This understanding will allow orthopedists to plan and execute the appropriate management, whether this may involve conservative or surgical intervention. The goal should always be to correct the abnormality and have the patient return to play with full strength and no recurrent instability.

Multidirectional instability of the shoulder: rotator interval dimension and capsular laxity evaluation using MR arthrography

OBJECTIVES

To compare the rotator interval and capsular dimension as measured on MR arthrography between patients with clinically diagnosed multidirectional instability (MDI) and control subjects with no instability.

MATERIALS AND METHODS

We retrospectively reviewed a consecutive series of 658 shoulders that had undergone MR arthrography between 2006 and 2010. Of these, 97 shoulders were included in the present study. These shoulders were divided into two groups according to the clinically established diagnoses. The MDI group comprised 47 shoulders with atraumatic multidirectional shoulder instability, and the control group comprised 50 shoulders with no instability. Two independent observers measured the width and depth of the rotator interval, and the capsular dimensions at the anterior, anteroinferior, inferior, posteroinferior, and posterior regions in the two groups using MR arthrography.

RESULTS

The rotator interval width and depth were significantly greater in the MDI group (width, observer 1, 17.7 mm, observer 2, 17.9 mm; depth, observer 1, 8.9 mm, observer 2, 8.8 mm) than in the control group (width, observer 1, 14.3 mm, observer 2, 14.5 mm; depth, observer 1, 5.9 mm, observer 2, 6.2 mm) (p < .001). The capsular dimensions at the inferior and posteroinferior regions were significantly larger in the MDI group (inferior, observer 1, 27.9 mm, observer 2, 27.8 mm; posteroinferior, observer 1, 27.0 mm, observer 2, 27.1 mm) than in the control group (inferior, observer 1, 25.7 mm, observer 2, 25.3 mm; posteroinferior, observer 1, 23.3 mm, observer 2, 23.6 mm) (p < .05). A width greater than 15.2 mm or a depth greater than 6.4 mm of the rotator interval, suggesting MDI, had sensitivities of 81 and 92 % for observer 1, and 79 and 94 % for observer 2, and specificities of 66 and 72 % for observer 1, and 62 and 66 % for observer 2, respectively.

CONCLUSIONS

Measurements of the rotator interval and the size of the distended inferior and posteroinferior joint capsule on MR arthrography are greater in shoulders with clinical MDI than in stable shoulders.

Evaluation and management of posterior shoulder instability

CONTEXT

Posterior shoulder instability is a commonly misdiagnosed disorder in many competitive athletes.

TYPE OF STUDY

Clinical review.

EVIDENCE ACQUISITION

Relevant studies on posterior shoulder instability from 1950 to 2010 in PubMed and Cochrane databases were reviewed.

RESULTS

A total of 107 studies were reviewed.

CONCLUSION

Patients who have undergone at least 6 months of physical therapy and still experience instability symptoms should be considered for surgical stabilization directed at their underlying pathology.

Management of multidirectional instability of the shoulder

Multidirectional shoulder instability is defined as symptomatic instability in two or more directions. Instability occurs when static and dynamic shoulder stabilizers become incompetent due to congenital or acquired means. Nonspecific activity-related pain and decreased athletic performance are common presenting complaints. Clinical suspicion for instability is essential for timely diagnosis. Several examination techniques can be used to identify increased glenohumeral translation. It is critical to distinguish increased laxity from instability. Initial management begins with therapeutic rehabilitation. If surgical management is required, capsular plication has been used successfully. Advanced arthroscopic techniques offer several advantages over traditional open approaches and may have similar outcomes. The role of rotator interval capsular plication is controversial, but it may be used to augment capsular plication in patients with specific patterns of instability. Despite encouraging results, outcomes remain inferior to those associated with traumatic unidirectional instability.

The rationale for an arthroscopic approach to shoulder stabilization

The gold standard of treatment for glenohumeral instability has traditionally been viewed as open shoulder stabilization. With the increased awareness of complex instability patterns and the ability to preoperatively detect concomitant pathology with advanced imaging modalities, an evidence-based shift to an all-arthroscopic approach to shoulder stabilization surgery is occurring. Current data suggest that patients who meet eligibility criteria for arthroscopic stabilization (those without significant bony lesions or significant deformity) can expect equivalent rates of recurrence, better functional outcomes, and less morbidity. Modern arthroscopic techniques using suture anchors and capsular plication have resulted in a significant improvement over previous reports in the orthopaedic literature. An argument is put forth on the benefits of an all-arthroscopic approach to shoulder stabilization in athletes and nonathletes alike based on a review of the current orthopaedic literature comparing the evolved arthroscopic technique with more traditional open methods.

Restoring the labral height for treatment of Bankart lesions: a comparison of suture anchor constructs

PURPOSE

The purpose of this study was to evaluate glenoid labral heights before injury and after repair with 2 suture anchors: (1) traditional suture anchor secured with knots and (2) knotless suture anchor.

METHODS

Ten matched pairs of human cadaveric glenoids were examined. In each specimen the labrum was detached from the 3-o'clock position to the 6:30 clock position on the anteroinferior glenoid, and labral repair was performed with either (1) traditional Bio-SutureTak suture anchors (n = 10) (Arthrex, Naples, FL) or (2) knotless PushLock suture anchors (n = 10, contralateral side) (Arthrex). By use of a 3-dimensional digitizer, the labral height, measured from the deepest point of the glenoid articular surface to the highest tip of the labrum, was measured in all specimens before injury and after repair at the 3:30, 4:30, and 5:30 clock positions. The degree of labral height increase was computed as a percent increase in labral height from before injury to after repair.

RESULTS

Labral height increased significantly for all specimens from before injury (5.35 mm) to after repair (8.05 mm) (159.1% +/- 13.7%, P < .0001). Increases in labral height from before injury to after repair were similar (P > .05) for Bio-SutureTak suture anchors (164.6% +/- 18.7%, P < .0001) and PushLock suture anchors (153.6% +/- 5.8%, P < .0001). The amount of labral height increase did not vary by anatomic location (157.0% +/- 50.2%, 168.9% +/- 51.0%, and 150.4% +/- 35.2% at 3:30, 4:30, and 5:30, respectively; P = .46).

CONCLUSIONS

An increase in labral height can be achieved to create a significant height increase from before injury to after labral repair. The difference in labral height afforded by a traditional suture anchor and a knotless anchor is not statistically significant.

CLINICAL RELEVANCE

Both traditional and knotless suture anchor constructs provide a reliable restoration of labral height in an acute Bankart model.

Multidirectional instability of the shoulder - current concept

A guest editorial on the multidirectional instability of the shoulder

Arthroscopic management of posterior shoulder instability: diagnosis, indications, and technique

With increased understanding of the different patterns of posterior shoulder instability, diagnostic acumen and successful treatment algorithms have evolved. Improvements in imaging and advancements in arthroscopic surgical techniques have facilitated this progress. In athletic populations, recurrent posterior subluxations (RPSs) are far more common than recurrent or locked posterior dislocations. Conservative and operative management of posterior instability is individualized to meet the demands of its diverse patient population, ranging from post-traumatic instability in contact athletes to RPSs in overhead athletes.

Complex shoulder disorders: evaluation and treatment

Evaluation of patients with shoulder disorders often presents challenges. Among the most troublesome are revision surgery in patients with massive rotator cuff tear, atraumatic shoulder instability, revision arthroscopic stabilization surgery, adhesive capsulitis, and bicipital and subscapularis injuries. Determining functional status is critical before considering surgical options in the patient with massive rotator cuff tear. When nonsurgical treatment of atraumatic shoulder stability is not effective, inferior capsular shift is the treatment of choice. Arthroscopic revision of failed arthroscopic shoulder stabilization procedures may be undertaken when bone and tissue quality are good. Arthroscopic release is indicated when idiopathic adhesive capsulitis does not respond to nonsurgical treatment; however, results of both nonsurgical and surgical treatment of posttraumatic and postoperative adhesive capsulitis are often disappointing. Patients not motivated to perform the necessary postoperative therapy following subscapularis repair are best treated with arthroscopic débridement and biceps tenotomy.

Imaging findings in posterior instability of the shoulder

Posterior shoulder instability refers to the symptoms and signs resulting from excessive posterior translation of the humerus. Magnetic resonance (MR) imaging is the radiological modality of choice in the diagnostic assessment of posterior instability. Computed tomography (CT) is useful in the evaluation of osseous abnormalities associated with posterior instability. A detailed description of the posterior osseous and labroligamentous abnormalities has evolved recently, and many variant lesions of the posteroinferior labrum and/or capsular structures have been described. As the recommended surgical management of lesions associated with posterior instability is a lesion-specific approach, awareness of the specific lesions that have been described in association with posterior instability helps in pre-surgical planning. The purpose of this article is to review the classification of, and injury mechanisms leading to, posterior shoulder instability and to describe imaging findings associated with posterior instability, with emphasis on MR imaging.

Scapular inclination and glenohumeral joint stability: a cadaveric study

BACKGROUND

In shoulders with multidirectional instability, translation of the humeral head on the glenoid is increased in the midrange because of the following three reasons: the increased retroversion, a hypoplastic posteroinferior rim, and decreased scapular abduction during arm elevation. This study aimed to clarify the relationship between glenoid inclination and glenohumeral joint stability.

METHODS

Nine fresh-frozen cadaveric shoulders were tested. With a 50-N compressive load, the translation force was measured in the 3-o'clock, 6-o'clock, 9-o'clock, and 12-o'clock directions by using a tilt of 0 degrees , 5 degrees , 10 degrees , 15 degrees , and 20 degrees . When the glenoid was tilted in one direction, the translation force was measured in the direction of inclination and in the opposite direction. The stability ratio was then calculated.

RESULTS

The stability ratio in the 3-o'clock direction significantly decreased with a tilt of more than 5 degrees in the 3-o'clock direction. The stability ratio in the 9-o'clock direction significantly decreased with a tilt of more than 15 degrees in the 9-o'clock direction and significantly increased with a tilt of more than 5 degrees in the 3-o'clock direction. The stability ratio in the 6-o'clock direction significantly increased with a tilt of more than 10 degrees in the 6-o'clock direction.

CONCLUSIONS

The posterior and inferior stability increased with an anterior tilt of more than 5 degrees and with a superior tilt of 10 degrees , respectively. The anterior and posterior stability decreased with an anterior tilt of 5 degrees and with a posterior tilt of 15 degrees , respectively.

Open and arthroscopic treatment of multidirectional instability of the shoulder

Multidirectional instability of the shoulder can be a difficult diagnostic and therapeutic dilemma for orthopaedic surgeons. First described by Neer and Foster, the mainstay of treatment is usually conservative, with most patients doing very well with nonoperative management. In patients with recalcitrant symptoms, surgical treatment primarily has been aimed at addressing the pathologically increased capsular volume. Newer studies suggest that the pathology also includes abnormal labral morphology and perhaps inadequate neuromuscular control. The arthroscopic treatment of multidirectional instability has come to have comparable results to open techniques when the multifactorial nature of the disease is recognized and the multiple techniques are used in combination to fully treat all pathology. Thermal capsulorrhaphy cannot be recommended at this time, except perhaps as an adjunct to other capsular plication or capsulorrhaphy techniques. The advantages of a less invasive procedure make arthroscopic capsular plication attractive, but it is associated with increased technical difficulty and a steep learning curve. Further studies are needed to distinguish a clear advantage of one over the other. Regardless of the technique used, the key to success is addressing the capsular laxity and redundancy to restore anatomic capsuloligamentous tension without overconstraining the shoulder.