The anterior labroligamentous periosteal sleeve avulsion lesion: a cause of anterior instability of the shoulder

Anterior Labrum Periosteal Sleeve Avulsion Lesions of the Shoulder: A Scoping Review

Background

Anterior labrum periosteal sleeve avulsion (ALPSA) lesion of the shoulder is defined as a labral avulsion with an intact periosteum of the glenoid neck resulting in medial malattachment of the labrum, which is both nonanatomic and nonfunctional. It is relatively rare compared with Bankart lesions, and its results are usually reported in combination with other anterior labroligamentous lesions in the literature.

Purpose

To (1) assess the size and scope of the literature on ALPSA lesions, (2) highlight the importance of this lesion, and (3) distinguish between ALPSA and Bankart lesions in diagnostic and treatment strategies.

Study Design

Scoping review; Level of evidence, 4.

Methods

The PubMed, Scopus, Embase, and Google Scholar databases were searched with the keywords "ALPSA,""anterior labrum periosteal sleeve avulsion,""anterior labral periosteal sleeve avulsion," and "anterior labroligamentous periosteal sleeve avulsion" lesion. Duplicate articles and those that did not meet the inclusion criteria were excluded, resulting in the identification of 42 relevant articles. Their references were analyzed for further data curation.

Results

This scoping review demonstrated that ALPSA lesions are difficult to clinically identify. Magnetic resonance angiography in the adduction internal rotation position is the most sensitive and specific imaging modality for identification. Optimal views are the anterosuperior portal for accurate identification and the anteroinferior portal for surgical repair during arthroscopy. Treatment begins with correctly identifying the labrum, in contradistinction to dense reactive fibrous tissue, and reattaching the labrum to the correct anatomic glenoid footprint. Chronic lesions with bone loss require either bone block or soft tissue augmentation procedures.

Conclusion

There is paucity of exclusive literature on ALPSA lesions. It is important to distinguish this lesion from the Bankart lesion as it is associated with worse outcomes. The higher failure rates of ALPSA lesion repair indicate that the current repair techniques require further refinement to improve the outcomes to the standard of Bankart lesions.

Thumb Metacarpal Periosteal Sleeve Avulsion: A Case Report

Periosteal sleeve fractures, or avulsions of cartilage and/or periosteum with or without an osseous fragment in skeletally immature individuals, are notoriously easy to miss and a high index of suspicion is necessary for accurate diagnosis and treatment. While periosteal sleeve avulsion fractures are classically reported in the patella, they have also been reported in the shoulder, clavicle, and elsewhere in the knee. However, no published reports exist for a periosteal sleeve avulsion fracture in the hand. This case details the first reported instance of such an injury involving a thumb metacarpal in a 3-year-old boy, treated with open reduction and percutaneous pinning of the thumb metacarpal.

Comparison of conventional MR arthrography and 3D volumetric MR arthrography in detection of cartilage defects accompanying glenoid labrum pathologies

OBJECTIVES

In this study, we aimed to compare conventional and T1-weighted volumetric magnetic resonance arthrography (MRA) in the diagnosis and grading of glenoid cartilage defects that accompany labral pathologies.

MATERIALS AND METHODS

A total of 79 patients who were prediagnosed with labrum pathologies based on shoulder magnetic resonance imaging (MRI) had MRA and CTA between December 2021 and May 2022. CTA was regarded as reference standard. CTA images were examined by a radiologist experienced in musculoskeletal radiology, and MRA images were examined by two radiologists independently to determine presence, grade, and localization of any glenoid cartilage defect, if present. Sensitivity, specificity, and accuracy were calculated separately for conventional and T1-weighted volumetric MRA. In addition, at the last stage, two observers examined all MRAs together, and the presence of a cartilage defect was decided by consensus, and the overall sensitivity, specificity, and accuracy were calculated.

RESULTS

Cartilage defect was detected on CTAs of 48 (60.75%) cases of among 79 patients with labrum pathology. The sensitivity, specificity, and accuracy of conventional MRA for two examiners were 17-19%, 100-100%, and 49-51%, respectively, while those values were 67-65%, 92-97%, and 84-77%, respectively, for T1-weighted volumetric MRA. Inter-examiner agreement was excellent for diagnosis of cartilage defects on all MRAs. The overall sensitivity, specificity, and accuracy for detection of glenoid cartilage lesions by MRA were 69%, 97%, and 80%, respectively.

CONCLUSION

T1-weighted volumetric MRA seems to demonstrate cartilage defects accompanied with labrum pathologies accurately with high sensitivity, specificity, and excellent inter-examiner agreement.

What keeps a shoulder stable - Is there an ideal method for anterior stabilisation?

The gleno-humeral joint is by far the most mobile in the human body but also afflicted by dislocations, predominantly anterior. Surgical stabilisation is often successful but failures not uncommon. The following review describes potential causes of failure and highlights the need of adapting surgical methods to pathomorphology.

Current Evidence Regarding Shoulder Instability in the Paediatric and Adolescent Population

Paediatric and adolescent shoulder instability is caused by a unique combination of traumatic factors, ligamentous laxity, and pattern of muscle contractility. The multifactorial nature of its aetiology makes interpretation of the literature difficult as nomenclature is also highly variable. The purpose of this review is to summarize the existing literature and shed light on the nuances of paediatric and adolescent shoulder instability. The epidemiology, clinical features, imaging, and management of all forms of paediatric shoulder instability are presented. The main findings of this review are that structural abnormalities following a dislocation are uncommon in pre-pubertal paediatric patients. Young post-pubertal adolescents are at the highest risk of failure of non-operative management in the setting of traumatic instability with structural abnormality, and early stabilisation should be considered for these patients. Remplissage and the Latarjet procedure are safe treatment options for adolescents at high risk of recurrence, but the side-effect profile should be carefully considered. Patients who suffer from instability due to generalized ligamentous laxity benefit from a structured, long-term physiotherapy regimen, with surgery in the form of arthroscopic plication as a viable last resort. Those who suffer from a predominantly muscle patterning pathology do not benefit from surgery and require focus on regaining neuromuscular control.

Lesion prevalence and patient outcome comparison between primary and recurrent anterior shoulder instability

BACKGROUND

The purpose of this study was to compare lesion prevalence and treatment outcomes in patients with primary and recurrent anterior shoulder instability.

METHODS

Patients who were admitted to the institution with a diagnosis of anterior shoulder instability and who underwent arthroscopic surgery between July 2006 and February 2020 were retrospectively evaluated. Minimum follow-up duration of the patients was 24 months. The recorded data and magnetic resonance imaging (MRI) of the patients were examined. Patients aged ≥40 years, with a history of shoulder region fracture, inflammatory arthritis, a history of epilepsy, multidirectional instability, nontraumatic dislocation, and off-track lesions were excluded from the study. Shoulder lesions were documented and patient outcome evaluation was made with the Oxford Shoulder Score (OSS) and visual analog scale (VAS).

RESULTS

A total of 340 patients were included in the study. The mean age of patients was 25.6 years (±6.49). The recurrent instability group had a significantly higher rate of anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesions compared to the primary instability group (40.6% vs. 24.6% respectively) (P = .033). Twenty-five patients (43.9%) had superior labrum anterior and posterior (SLAP) lesions in the primary instability group and 81 patients (28.6%) had SLAP lesions in the recurrent instability group (P = .035). OSS increased for both primary (from 35 [16-44] to 46 [36-48]) (P = .001) and recurrent instability groups (from 33 [6-45] to 47 [19-48]) (P = .001). There was no significant difference between the groups regarding postoperative VAS and OSS scores (P > .05).

CONCLUSIONS

Successful results were obtained in patients younger than 40 years with both primary and recurrent anterior shoulder instability after arthroscopic treatment. ALPSA lesion prevalence was higher whereas SLAP lesion prevalence was lower in patients with recurrent instability. Although the postoperative OSS was comparable between the patient groups, the failure rate was higher in the recurrent instability patients.

Surgical Outcomes and Associated Injuries of Anterior Labroligamentous Periosteal Sleeve Avulsion (ALPSA) Lesions: A Systematic Review

Introduction

Anterior Labroligamentous Periosteal Sleeve Avulsion (ALPSA) lesions can lead to chronic shoulder instability and repetitive dislocations in active populations.

Objective

The purpose of this systematic review was to evaluate associated injuries and postoperative outcomes following ALPSA lesion repairs.

Methods

Medline, Embase, Cochrane, and Web of Science were searched through May 2022 for studies that investigated management and surgical outcomes of ALPSA lesion repair. Data was extracted on the following topics: surgical management, surgical complications, associated injuries, follow-up duration, and outcome parameters, including recurrence rates, functional outcome scores, range-of-motion (ROM), and return to activity.

Results

A total of 6 studies covering 202 patients met the inclusion criteria. In the included studies, 79% of patient were male with a mean age of 25.1 years. A total of 192 associated injuries were reported amongst 176 patients with the most common being Hill Sachs lesions (84, 43.8%), synovitis (35, 18.2%), SLAP tears (32, 16.7%) and glenoid erosions or lesions (30, 15.6%). All 202 patients were treated arthroscopically with no reported complications. 26 patients (12.9%) experienced operative failure as evidenced by recurrence of shoulder instability over a mean follow-up of 4.3 years. Various clinical outcome scores showed postoperative functional improvement and one study reported a 100% return to activity rate in 26 patients.

Conclusion

Our findings suggest a high 12.9 % risk of recurrence following ALPSA repair but satisfactory functional outcomes, both of which should be weighed by physicians when considering arthroscopic repair. Physicians should also be cognizant of co-pathologies when examining patients with suspected ALPSA lesions.

Concomitant Glenolabral Articular Disruption (GLAD) Lesion is Not Associated With Inferior Clinical Outcomes After Arthroscopic Bankart Repair for Shoulder Instability: A Retrospective Comparative Study

Purpose

The purpose of this study was to compare outcomes between anterior shoulder instability patients with and without glenolabral articular disruption (GLAD) lesions after undergoing arthroscopic Bankart repair and to evaluate potential risk factors for inferior outcomes and recurrent instability.

Methods

Prospectively collected data were retrospectively reviewed for patients who underwent arthroscopic Bankart repair with and without GLAD lesions at a minimum of 2 years follow-up. Consecutive patients were matched by age, sex, and number of anchors. Patient-reported outcomes (PROs) were evaluated before and after surgery, including American Shoulder and Elbow Surgeons, Single Assessment Numeric Evaluation, Quick Disabilities of the Arm, Shoulder and Hand, Short Form-12 score, and satisfaction. Recurrent dislocation, subjective instability, and reoperation were analyzed. Additionally, PROs were assessed on the basis of GLAD lesion characteristics.

Results

A total of 54 patients (27 GLAD, 27 control) with a mean age of 28.9 ± 11.6 years were analyzed at mean 4.5 ± 1.9 years (range, 2-9 years) follow-up. Thirty-eight (70.3%) of the participants were male. Patients in both groups experienced significant improvements in all PROs (P ≤ .006 for all measures) and reported high median satisfaction (scale 1-10: 10 vs 10, P = .290) at final follow-up. Two patients in the GLAD cohort and 1 in the control cohort underwent reoperation (P = .588). Four (14.8%) patients in each group reported recurrent dislocation (P = 1.0). Additionally, 2 (7.4%) GLAD patients and 1 (3.7%) control patient reported subjective shoulder instability after surgery (P = 1.0). No significant differences in PROs were observed based on anchor/labral advancement or treatment with microfracture, nor were significant correlations observed between GLAD lesion size and PROs (P > .05 for all).

Conclusion

Arthroscopic Bankart repair in patients with GLAD lesions resulted in significantly improved outcomes with high satisfaction, which was no different when compared with those without GLAD lesions.

Level of Evidence

Level III, retrospective comparative study.

Outcomes of Arthroscopic Anterior Labroligamentous Periosteal Sleeve Avulsion Lesions: A Minimum 2-Year Follow-up

BACKGROUND

Anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesions can occur in recurrent anterior shoulder instability, which may lead to the labrum scarring medially to the glenoid. ALPSA lesions have also been associated with greater preoperative dislocations, larger Hill-Sachs lesions, and greater degrees of glenoid bone loss. Therefore, patients with these lesions have historically had a higher failure rate after repair, with nearly double the recurrent instability rate compared with those undergoing standard arthroscopic Bankart repair.

PURPOSE

To compare minimum 2-year outcomes of arthroscopic mobilization and anatomic repair of ALPSA lesions with those after standard arthroscopic Bankart repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Consecutive patients who underwent arthroscopic repair of ALPSA lesions were matched in a 1-to-3 fashion to patients who underwent standard Bankart repair by age, sex, number of previous ipsilateral shoulder instability surgical procedures, and number of anchors used. Patient-reported outcome (PRO) scores were compared preoperatively and postoperatively (American Shoulder and Elbow Surgeons [ASES]; 12-Item Short Form Health Survey [SF-12] Physical Component Summary [PCS]; Single Assessment Numeric Evaluation [SANE]; shortened version of Disabilities of the Arm, Shoulder and Hand; and satisfaction). Recurrent instability, on- versus off-track Hill-Sachs lesion, and reoperation rates were analyzed.

RESULTS

A total of 100 shoulders (25 ALPSA and 75 Bankart) with an overall mean age of 25.7 years were evaluated. Patients in the ALPSA group demonstrated significant improvements in the ASES (preoperative, 74.8; postoperative, 89.7; P = .041) and SF-12 PCS (preoperative, 46.9; postoperative, 53.4; P = .021) scores but not the SANE score (preoperative, 65.2; postoperative, 75.3; P = .311). Patients in the Bankart group had significant improvements in all outcome scores at final follow-up: ASES (preoperative, 67.1; postoperative, 90.3), SANE (preoperative, 58.0; postoperative, 85.7), and SF-12 PCS (preoperative, 45.3; postoperative, 52.9) (all P < .001). There were no significant differences in PRO scores between the groups preoperatively or postoperatively (P > .05). The median satisfaction for the ALPSA group was 10 of 10 and for the Bankart group it was 9 of 10 (P = .094). There was a significantly higher rate of recurrent dislocation in the ALPSA group (8/25 [32.0%]) compared with the Bankart group (10/75 [13.3%]) (P = .040). Additionally, 5 patients (20.0%) in the ALPSA group underwent revision surgery at a mean of 5.6 years, and 8 patients (10.7%) in the Bankart group underwent revision surgery at a mean of 4.4 years (P = .311).

CONCLUSION

Despite improvements in the recognition of and surgical techniques for ALPSA lesions, they still lead to significantly higher postoperative dislocation rates; however, no differences in PRO scores were found. These findings highlight the importance of early surgical interventions in anterior shoulder instability with the hope of lessening recurrent instability and the risk of developing an ALPSA lesion, as well as careful assessment of the quality of soft tissues and other risk factors for recurrence when considering what type of shoulder stabilization procedure to perform.

Anatomical, functional and biomechanical review of the glenoid labrum

The glenohumeral joint is the most mobile joint in the human skeleton, supported by both active and passive stabilisers. As one of the passive stabilisers, the glenoid labrum has increasingly been recognised to play an important role in stability of the glenohumeral joint, acting to maintain intraarticular pressure, centralise the humeral head and contribute to concavity-compression stability. Several studies have investigated the macro- and micro-anatomical features of the labrum as well as its biomechanical function. However, in order to better understand the role of the labrum and its mechanics, a comprehensive anatomical, functional and biomechanical review of these studies is needed. Therefore, this article reviews the current literature detailing anatomical descriptions of the glenoid labrum, with an emphasis on its function(s) and biomechanics, as well as its interaction with neighbouring structures. The intimate relationship between the labrum and the surrounding structures was found to be important in glenohumeral stability, which owes further investigation into the microanatomy of labrum to better understand this relationship.

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

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

Shoulder: Instability

Glenohumeral instability is the inability to keep the humeral head centered in the glenoid fossa. Glenohumeral instability can be classified according to etiology and direction of instability. The glenoid labrum, the glenohumeral ligaments, and the bony structures contribute to the stability glenohumeral joint and need to be addressed with imaging. One of the difficulties with accurately diagnosing labral tears on MR imaging is the normal labral variants, which can sometimes appear similar to tears. The location and extent of a Hill-Sachs lesion and glenoid rim defects need to be related to recognize engaging Hill-Sachs lesions or off-track situations. There are several types of labral tears that are not associated with a prior dislocation. SLAP tears are one of the more common tears of the labrum and can sometimes be difficult to distinguish from a normal variant superior sublabral recess. Labral tears in overhead thrower occur in the posterosuperior labrum, adjacent to the posterior rotator cuff tears in these athletes. Tears in the posterosuperior labrum are also associated with spinoglenoid notch paralabral cysts, which can be painful and cause external rotation weakness.

Arthroscopic Bankart Repair With and Without Curettage of the Glenoid Edge: A Prospective, Randomized, Controlled Study

PURPOSE

To determine whether curettage of the cartilage on the glenoid edge in arthroscopic Bankart repair reduces the postoperative recurrence rate compared with noncuretted glenoid.

METHODS

Between January 2010 and December 2013, 134 patients underwent arthroscopy and stabilization for recurrent anterior dislocation of shoulder; 42 patients were excluded. Alternate glenoid edge was curetted in 92 patients undergoing arthroscopic Bankart repair. Twelve patients were lost to follow-up. The remaining 80 patients were divided into 2 groups of 40 patients each, curettage and noncurettage. In both groups, the Bankart lesion was repaired using ≥3 bioanchors loaded with nonabsorbable braided sutures. Postoperative rehabilitation was the same for the 2 groups. We recorded recurrence of instability, pain, and Constant and Rowe shoulder scores. Statistical analysis of data was performed using unpaired t test (significance level P < .05).

RESULTS

The 2 groups were comparable in terms of age, number of dislocations, and bone loss. The average follow-up was 7 years and 9 months (range 6 to 10 years). Of the total 40 patients in the curettage group, 6 (15%) had recurrence of dislocation and none had subluxations, whereas in the noncurettage group, 13 (32.5%) had recurrence of dislocation and 3 (7.5%) had subluxations. The difference in postoperative recurrence of instability was statistically significant (P = .012). The average (standard deviation) Rowe score was 83.75 (23.28) in the curettage group and 70.13 (31.29) in the noncurettage group (P = .030).

CONCLUSIONS

During arthroscopic Bankart repair, curettage of the cartilage on the anterior glenoid edge reduces the incidence of postoperative recurrence of instability.

LEVEL OF EVIDENCE

II, therapeutic; prospective, randomized, controlled study.

Diagnosis and Management of Traumatic Anterior Shoulder Instability

Anterior shoulder instability is the most common form of shoulder instability and is usually because of a traumatic injury. Careful patient selection is key to a favorable outcome. Primary shoulder stabilization should be considered for patients with high risk of recurrence or for elite athletes. Soft-tissue injury to the labrum, capsule, glenohumeral ligament, and rotator cuff influence the outcome. Glenoid bone loss (GBL) and type of bone loss (on-track/off-track) are important factors when recommending treatment strategy. Identification and management of concomitant injuries are paramount. The physician should consider three-dimensional CT reconstructions and magnetic resonance arthrography when concomitant injury is suspected. Good results can be expected after Bankart repair in on-track Hill-Sachs lesions (HSLs) with GBL < 13.5%. Bankart repair without adjunct procedures is not recommended in off-track HSLs, regardless of the size of GBL. If GBL is 13.5% to 25% but on-track, adjunct procedures to Bankart repair should be considered (remplissage and inferior capsular shift). Bone block transfer is recommended when GBL > 20% to 25% or when the HSL is off-track. Fresh tibia allograft or lilac crest autograft are good treatment options after failed bone block procedure.

The glenohumeral ligaments: Superior, middle, and inferior: Anatomy, biomechanics, injury, and diagnosis

The three glenohumeral ligaments (superior, middle, and inferior) are discrete thickenings of the glenohumeral joint capsule and are critical to shoulder stability and function. Injuries to this area are a cause of significant musculoskeletal morbidity. A literature search was performed by a review of PubMed, Google Scholar, and OVID for all relevant articles published up until 2020. This study highlights the anatomy, biomechanical function, and injury patterns of the glenohumeral ligaments, which may be relevant to clinical presentation and diagnosis. A detailed understanding of the normal anatomy and biomechanics is a necessary prerequisite to understanding the injury patterns and clinical presentations of disorders involving the glenohumeral ligaments of the shoulder.

The broken circle method: a novel technique that enhances detection of Hill-Sachs lesions on internal rotation shoulder radiographs

AIM

To describe and test a new method that increases the conspicuity of a Hill-Sachs lesion on internal rotation (IR) radiographs.

MATERIALS AND METHODS

This study had institutional review board approval. A retrospective search for patients with a prior shoulder dislocation and a Hill-Sachs lesion documented on magnetic resonance imaging (MRI) was performed over a 10-year period identifying 256 test patients. In Part 1, the IR radiographs from test cases were randomised with controls, and three readers scored them independently for the defect. The readers were then taught the Broken Circle (BC) method and re-scored the radiographs. In Part 2, 15 cases of Hill-Sachs lesions that were missed by all readers in Part 1 were randomised with controls, and were shown to 25 radiology residents before (pre-test) and after (post-test) learning the BC method. A paired t-test was used to compare the differences in sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

In Part 1, the sensitivity increased 19.7% (54.1%-73.8%; p<0.05) and NPV increased 10.8% (62.5%-73.3%; p<0.01). In Part 2, post-test sensitivity for residents increased 16.3% (55.2%-71.5%; p<0.0001), accuracy increased 13.4% (64%-77.4%; p<0.0001), and NPV increased 13.3% (40.8%-54.1%; p<0.0001) independent of the level of training. The change in accuracy was also statistically significant for every individual class.

CONCLUSION

The BC method was an effective technique that facilitated detection of a Hill-Sachs lesion at all levels of training, and was useful as a teaching tool.

Editorial Commentary: Evidence to Support Surgical Intervention for First-Time Shoulder Instability: Stabilize Them Early!

Historically, a primary anterior instability event has been treated nonoperatively. In the literature, a multitude of outcome scores and definitions for recurrence of instability complicates the interpretation and synthesis of evidence-based recommendations. However, there is an emerging body of high-quality evidence that early surgical stabilization yields better overall outcomes. A wait-and-see approach would be acceptable if it was without detrimental effects, but there is a cost to recurrence of instability events, such as more extensive soft-tissue, cartilage, and bony lesions. Young age, male sex, and contact sport participation have been identified as risk factors for recurrence of anterior shoulder instability, and today, these patients are routinely recommended surgical treatment. It is also paramount to identify concomitant injury following the primary anterior instability event. The sensitivity, specificity, and reliability of radiographs is suboptimal, and the threshold to obtain advanced imaging such as computed tomography or magnetic resonance imaging with 3-dimensional reconstructions should be low. Taking into account the low non-recurrence complication rate following arthroscopic stabilization, early surgical intervention should be considered following the first instability event.

Arthroscopic Fixation of an Anterior Labroligamentous Periosteal Sleeve Avulsion (ALPSA) of the Shoulder

Anterior labroligamentous periosteal sleeve avulsions represent a diagnostic and treatment challenge. They are associated with a higher number of preoperative dislocations, as well as longer chronicity, and commonly result in a scarred and medialized labrum and periosteal sleeve complex. Anterior labroligamentous periosteal sleeve avulsion lesions therefore may be commonly overlooked. The complexity of the injury pattern has been associated with double the failure rate of standard Bankart lesions after arthroscopic repair. The purpose of this article is to describe our preferred arthroscopic technique for achieving full mobilization of the labral-periosteal complex and restore it to its anatomic location using a knotless, all-suture anchor construct.

Capsular Injury and Inflammation

The capsular and ligamentous structures of the glenohumeral joint are important for stability of the shoulder. These structures are best evaluated by MR imaging. Familiarity with normal and abnormal appearance of the capsular structures of the shoulder is important to ensure that important pathology is not overlooked. Injury to the capsular structures can occur in the setting of trauma and most commonly involves the inferior glenohumeral ligament and axillary pouch. Adhesive capsulitis is a common inflammatory condition with characteristic imaging features that should be considered in the absence of alternative diagnoses.

A Biomechanical Comparison of Two Techniques of Latarjet Procedure in Cadaveric Shoulders

Traumatic anterior instability of the shoulder is commonly treated with the Latarjet procedure, which involves transfer of the coracoid process with a conjoint tendon to the anterior aspect of the glenoid. The two most common techniques of the Latarjet are the classical and congruent arc techniques. The aim of this study was to evaluate the difference in force required to dislocate the shoulder after classical and congruent arc Latarjet procedures were performed. Fourteen cadaveric shoulders were dissected and osteotomised to produce a bony Bankart lesion of 25% of the articular surface leading to an “inverted pear-shaped” glenoid. An anteroinferior force was applied whilst the arm was in abduction and external rotation using a pulley system. The force needed to dislocate was noted, and then the shoulders underwent coracoid transfer with the classical and congruent arc techniques. The average force required to dislocate the shoulder after osteotomy was 123.57 N. After classical Latarjet, the average force required was 325.71 N, compared with 327.14 N after the congruent arc technique. This was not statistically significant. In this biomechanical cadaveric study, there is no difference in the force required to dislocate a shoulder after classical and congruent arc techniques of Latarjet, suggesting that both methods are equally effective at preventing anterior dislocation in the position of abduction and external rotation.

Arthroscopic glenoid labral lesion repair using all-suture anchor for traumatic anterior shoulder instability: short-term results

BACKGROUND

This study presents the preliminary clinical results of arthroscopic glenoid labral lesion repair using all-suture anchors in the treatment of recurrent traumatic anterior shoulder instability.

METHODS

Seventy patients who underwent arthroscopic shoulder stabilization for traumatic anterior shoulder instability were evaluated in this single center-based retrospective study. Patients with a glenoid defect greater than 20%, off-track engaging Hills-Sachs lesion, multidirectional instability, and generalized ligamentous laxity were excluded. The 62 included patients treated with arthroscopic glenoid labral lesion repair using all-suture anchors were evaluated. The Rowe and Constant scores were used to assess the results.

RESULTS

We evaluated 62 patients with a mean age of 26.7 ± 12 years. The mean Rowe and Constant scores were 35 ± 7.2 and 65 ± 6.3, respectively, preoperatively and increased to 93.6 ± 5.3 and 92 ± 4.3, respectively, postoperatively at the mean follow-up of 28.8 months (range, 24-48 months) (P < .001). The redislocation rate was 8.1%. Of the patients, 91.9% had good to excellent clinical scores. Younger age and contact sports were associated with a higher risk of recurrent dislocation (P = .012 and P = .041, respectively). The postoperative functional results were not significantly correlated with the findings concerning the number of dislocations, time until surgery, degree of anterior translation, and number of anchors.

CONCLUSION

The use of all-suture anchors for arthroscopic glenoid labral lesion repair for the treatment of recurrent traumatic anterior shoulder instability yields satisfactory clinical results and is a safe and effective option.

Incidence of gadolinium or fluid signal within surgically proven glenoid labral tears at MR arthrography

OBJECTIVE

To determine how often patients with surgically proven labral tears have labral signal on shoulder MR arthrography (MRA) that is not equal to gadolinium or fluid on T1- and T2-weighted images, respectively.

MATERIALS AND METHODS

Consecutive patients with surgical repair of a SLAP or Bankart labral tear within 95 days of an MRA were included. Using cartilage signal as an internal reference, two musculoskeletal (MSK) radiologists retrospectively categorized labral signal as T1-hyperintense, T1-gadolinium, T2-hyperintense, or T2-fluid. In patients without T1-gadolinium or T2-fluid labral signal, secondary findings such as the orientation, extent, shape, and width of the abnormal signal was recorded. Statistical analyses were performed using Fisher's test and ANOVA.

RESULTS

Sixty-one labral tears (36 SLAP and 25 Bankart) in 54 patients (mean age, 30.7; F:M 8:46) met the inclusion criteria. In 67% and 76% of SLAP and Bankart labral tears, T1-gadolinium signal was present (p = 0.43). T2-fluid signal was present in 50% and 92% of these same labral tears (p = 0.001). The absence of T1-gadolinium or T2-fluid signal was more common in SLAP tears (33%) compared to Bankart tears (8%) (p = 0.02). In the SLAP cases, at least two secondary findings of a SLAP tear were present in 92% (11/12).

CONCLUSIONS

Lack of surfacing T1-gadolinium or T2-fluid labral signal is unusual in Bankart tears but relatively common in SLAP tears. However, a SLAP tear was diagnosed in 92% of these 12 cases when two secondary findings were present.

Diagnostic Shoulder Arthroscopy: Surgical Technique

Shoulder arthroscopy is the second most common orthopaedic procedure. Diagnostic arthroscopy of the shoulder requires an efficient and reproducible technique. In this Technical Note, we describe a step-wise approach to diagnostic arthroscopy of the shoulder. This technique is performed using a posterior viewing portal. It can be performed from the beach chair or the lateral decubitus position. This technique uses a 2-circle approach: the surgeon first evaluates the glenoid aspect of the joint space, followed by the humeral aspect of the joint space. This method ensures a complete and consistent evaluation of the glenohumeral joint.

Heterotopic Ossification Under an Anterior Labroligamentous Periosteal Sleeve Avulsion Lesion That Was Incorrectly Identified as a Fracture of the Anterior Glenoid Rim (a Bony Bankart Lesion): A Report of 3 Cases

CASES

Senior musculoskeletal radiologists diagnosed fractures of the anterior glenoid rim (osseous Bankart lesions) in 3 patients with shoulder instability who had routine imaging. However, additional assessment suggested that the images were more consistent with heterotopic ossification under an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion with no true osseous Bankart lesion and no substantial bone loss.

CONCLUSION

Recognition of the lesion described in this article is important to prevent potential misdiagnosis and may assist in surgical decision-making.

Risk Factors for Recurrence of Anterior-Inferior Instability of the Shoulder After Arthroscopic Bankart Repair in Patients Younger Than 30 Years

PURPOSE

To identify the risk factors for recurrent instability after arthroscopic Bankart repair and evaluate the recurrence rate and functional outcomes.

METHODS

A retrospective review was performed of patients with anterior-inferior shoulder instability who underwent arthroscopic Bankart repair between 2008 and 2014. Patients below 30 years of age who were available for follow-up at least for 2 years were sorted into 2 groups according to the presence of recurrent instability. Furthermore, statistical analysis by binary logistic regression analysis included the significance of various risk factors including gender, demographic factors, number of preoperative dislocations, time interval between the first dislocation and the surgery (shorter than 6 months or not), generalized hyperlaxity, concomitant injury, bony Bankart, and off-track lesion. The functional outcomes were assessed with the Rowe and Walch-Duplay scores.

RESULTS

A total of 170 shoulders were included (without-recurrence group: 138, recurrent group: 32). The overall postoperative recurrent instability rate was 18.8%. SLAP repair, interval closure, and capsular plication were performed when necessary. However, these additional procedures were not influenced by recurrence (P = .37). The 2 groups showed significant differences in the number of preoperative dislocations (P = .048; adjusted odds ratio [OR] 2-5 times, 6.41; more than 5 times, 8.77), time interval between the first dislocation and surgery (P = .003, adjusted OR 5.62), and off-track Hill-Sachs lesion (P = .04, adjusted OR 4.31). There was significant improvement in the mean Rowe and Walch-Duplay scores at 2 years postoperatively (P < .001 in both cases), but the mean scores were lower in the group with recurrence than in the group without (P = .021 and .014, respectively).

CONCLUSIONS

The overall results suggest that surgery within 6 months of the first dislocation should be considered, with meticulous attention in patients with a high number of preoperative dislocations or off-track Hill-Sachs lesions.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Effect of Anterior Glenoid Labral Tears and Glenoid Bone Loss at the NFL Combine on Future NFL Performance

Background:

Anterior glenohumeral instability is a common abnormality in the young, athletic population, especially in those participating in contact or collision sports.

Purpose:

To examine the effect of anterior labral tears, their associated injuries, and their management on future National Football League (NFL) performance.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective review of all NFL Combine participants from 2009 to 2015 was performed using medical and imaging reports compiled at the NFL Combine. These notes and images were reviewed and analyzed for involved structures, associated injuries, and evidence of previous surgical interventions. The respective NFL draft position, number of NFL games played, number of NFL games started, and NFL snap percentage for each player’s first 2 seasons were collected and compared with a control group and within subgroups.

Results:

Of the 2285 players at the NFL Combine between 2009 and 2015, there were 206 (9%) anterior labral tears confirmed by magnetic resonance imaging, 20 of which were bilateral, for a total of 226 affected shoulders. There were 908 players who fit the criteria for inclusion in the control group. Overall, there were no significant differences between players with anterior labral tears and the control players in terms of draft position (P = .259), games played in their first 2 NFL seasons (P = .391), games started in their first 2 NFL seasons (P = .486), or snap percentage in their first (P = .268) and second (P = .757) NFL seasons. In general, sustaining a concomitant injury with an anterior labral tear (superior labrum from anterior to posterior [SLAP] tear, glenoid bone loss, Hill-Sachs lesion, rotator cuff tear, humeral avulsion of the glenohumeral ligament, and anterior tear combined with posterior tear) negatively affected a player’s NFL draft position when compared with those with an isolated anterior labral tear (P = .003). There was no significant difference between operative and nonoperative management for anterior labral tears in terms of any performance metric.

Conclusion:

A history of anterior labral tears was not significantly associated with future NFL performance. While players with isolated injuries were drafted significantly earlier than those with concomitant injuries, combined injuries did not affect players’ games played, games started, or snap percentage in their first 2 NFL seasons. Glenoid bone loss did significantly decrease draft position; however, the severity of bone loss did not affect draft position, and there were no significant associations between glenoid bone loss and games played, games started, or snap percentage.

Anterior Glenohumeral Instability

Anterior shoulder dislocations, subluxations, and recurrent instability of the shoulder joint are common problems usually affecting a young active population. However, it can be a problem for patients up to the late decades in life and can lead to major shoulder arthropathy if left untreated or improperly treated. This article discusses the natural history, pathologic morphologic changes of the shoulder joint associated with anterior instability along with normal anatomic variants. We will also discuss current treatment recommendations and possible causes of the patient with recurrent instability despite prior stabilization procedures.

High-resolution MRI of the ulnar and radial collateral ligaments of the wrist

Background Accurate diagnosis of injuries to the collateral ligaments of the wrist is technically challenging on MRI. Purpose To investigate usefulness of high-resolution two-dimensional (2D) and isotropic three-dimensional (3D) magnetic resonance imaging (MRI) for identifying and classifying the morphology of the ulnar and radial collateral ligaments (UCL and RCL) of the wrist. Material and Methods Thirty-seven participants were evaluated using 3T coronal 2D and isotropic 3D images by two radiologists independently. The UCL was classified into four types: 1a, narrow attachment to the tip of the ulnar styloid (Tip); 1b, broad attachment to the Tip; 2a, narrow attachment to the medial base of the ulnar styloid (Base); and 2b, broad attachment to the Base. The RCL was also classified into four types: 1a, separate radioscaphoid and scaphotrapezial ligaments (RS + ST) with narrow scaphoid attachment; 1b, RS + ST with broad scaphoid attachment; 2a, continuous radio-scapho-trapezial ligaments (RST) with narrow scaphoid attachment; and 2b, RST with broad scaphoid attachment. The inter-observer reliability of these classifications was calculated. Results Type 1a was the most common of both collateral ligaments. Of UCL classifications, 31.4% were revised after additional review of multiplanar reconstruction (MPR) images from isotropic data. The inter-observer reliability of UCL classification was substantial (k = 0.62) without MPR, and almost perfect (k = 0.84) with MPR. The inter-observer reliability of RCL classification was almost perfect (k = 0.89). Anatomic delineation between the two sequences was not statistically different. Conclusion The UCL and RCL were each identified on high-resolution 2D and isotropic 3D MRI equally well. MPR allows accurate identification of the UCL attachment to the ulnar styloid.

The Epidemiology and Natural History of Anterior Shoulder Instability

PURPOSE OF REVIEW

The purpose of this review is to outline the natural history and best clinical practices for nonoperative management of anterior shoulder instability.

RECENT FINDINGS

Recent studies continue to demonstrate a role for nonoperative treatment in the successful long-term management of anterior glenohumeral instability. The success of different positions of shoulder immobilization is reviewed as well. There are specific patients who may be best treated with nonoperative means after anterior glenohumeral instability. There are also patients who are not good nonoperative candidates based on a number of factors that are outlined in this review. There continues to be no definitive literature regarding the return to play of in-season athletes. Successful management requires a thorough understanding of the epidemiology, pathoanatomy, history, physical examination, diagnostic imaging modalities, and natural history of operative and nonoperative treatment.

Natural History of Anterior Shoulder Instability

BACKGROUND

The shoulder is the most complex joint in the body. The large freedom of motion in this joint is the main cause of instability. Instability varies in its degree, direction, etiology and volition and there is a large spectrum of conditions.

METHODS

Based on literature research and also in our own experience, we propose to elucidate the reader about the natural history of instability and its importance for the appropriate management of this pathology, by answering the following questions: What happens in the shoulder after the first dislocation? Which structures suffer damage? Who are the patients at higher risk of recurrence? How does the disease evolve without treatment? Will surgical treatment avoid future negative outcomes and prevent degenerative joint disease? Who should we treat and when?

RESULTS

80% of anterior-inferior dislocations occur in young patients. Recurrent instability is common and multiple dislocations are the rule. Instability is influenced by a large number of variables, including age of onset, activity profile, number of episodes,delay between first episode and surgical treatment.

CONCLUSION

Understanding the disease and its natural evolution is determinant to decide the treatment in order to obtain the best outcome. It is crucial to identify the risk factors for recurrence. Delay in surgical treatment, when indicated, leads to worse results. Surgical technique should address the type and severity of both soft tissue and bone lesions, when present.

Controversies In The Surgical Management Of Shoulder Instability: Associated Soft Tissue Procedures

Background:

The glenohumeral joint is a ball-and-socket joint that is inherently unstable and thus, susceptible to dislocation. The traditional and most common anatomic finding is the Bankart lesion (anterior-inferior capsule labral complex avulsion), but there is a wide variety of anatomic alterations that can cause shoulder instability or may be present as a concomitant injury or in combination, including bone loss (glenoid or humeral head), complex capsule-labral tears, rotator cuff tears, Kim´s lesions (injuries to the posterior-inferior labrum) and rotator interval pathology.

Methods:

A review of articles related to shoulder anatomy and soft tissue procedures that are performed during shoulder instability arthroscopic management was conducted by querying the Pubmed database and conclusions and controversies regarding this injury were exposed.

Results:

Due to the complex anatomy of the shoulder and the large range of movement of this joint, a wide variety of anatomic injuries and conditions can lead to shoulder instability, specially present in young population. Recognizing and treating all of them including Bankart repair, capsule-labral plicatures, SLAP repair, circumferential approach to pan-labral lesions, rotator interval closure, rotator cuff injuries and HAGL lesion repair is crucial to achieve the goal of a stable, full range of movement and not painful joint.

Conclusion:

Physicians must be familiarized with all the lesions involved in shoulder instability, and should be able to recognize and subsequently treat them to achieve the goal of a stable non-painful shoulder. Unrecognized or not treated lesions may result in recurrence of instability episodes and pain while overuse of some of the techniques previously described can lead to stiffness, thus the importance of an accurate diagnosis and treatment when facing a shoulder instability.

Radiographic Evaluation of Patients with Anterior Shoulder Instability

PURPOSE OF REVIEW

Injuries to the labrum, joint capsule (in particular the inferior glenohumeral ligament), cartilage, and glenoid periosteum are associated with anterior shoulder instability. The goal of this review is to provide common radiographic images and findings in patients with anterior shoulder instability. Furthermore, we will demonstrate the best methods for measuring anterior glenoid bone loss.

RECENT FINDINGS

Magnetic resonance (MR) imaging is highly relied upon for evaluating anterior shoulder instability and can diagnose soft tissue injuries with high sensitivity. While 3D computed tomography (CT) scan has been considered the optimal tool for evaluating osseous defects, certain MR imaging sequences have been shown to have similar diagnostic accuracy. Repair of Bankart lesions is critical to stabilizing the shoulder, and in the recent years, there has been an increasing focus on imaging to accurately characterize and measure glenoid bone loss to properly indicate patients for either arthroscopic repair or anterior bony reconstruction. Furthermore, Hill-Sachs lesions are commonly seen with shoulder instability, and importance must be placed on measuring the size and depth of these lesions along with possible engagement, as these factors will dictate management. The labral-ligamentous complex and rotator cuff are primary stabilizers of the shoulder. With anterior shoulder instability, the labrum is frequently injured. MRI with an arthrogram or provocative maneuvers is the gold standard for diagnosis. Various imaging modalities and methods can be performed to identify and measure Bankart and Hill-Sachs lesions, which can then be used for surgical planning and treating shoulder instability.

Imaging the Glenoid Labrum and Labral Tears

The shoulder joint is the most unstable articulation in the entire human body. While this certainly introduces vulnerability to injury, it also confers the advantage of broad range of motion. There are many elements that work in combination to offset the inherent instability of the glenohumeral joint, but the glenoid labrum is perhaps related most often. Broadly, clinical unidirectional instability can be subdivided into anterior and posterior instability, which usually raise concern for anteroinferior and posteroinferior labral lesions, respectively. In the special case of superior labral damage, potential dislocation is blocked by structures that include the acromion; hence, while damage elsewhere commonly manifests as clinical instability, damage to the superior labrum is often described by the term microinstability. In this particular case, one of the radiologist's main concerns should be classic superior labral anteroposterior lesions. The glenoid labrum is also subject to a wide range of normal variants that can mimic labral tears. Knowledge of these variants is central to interpreting an imaging study of the labrum because misdiagnosis of labral variants as tears can lead to superfluous surgical procedures and decreased shoulder mobility. This article reviews labral anatomy and normal labral variants, describes their imaging features, and discusses how to discriminate normal variants from labral tears. Specific labral pathologic lesions are described per labral quadrant (anteroinferior, posteroinferior, and superior), and imaging features are described in detail. Online supplemental material is available for this article. ^©RSNA, 2016.

Arthroscopic Findings in Anterior Shoulder Instability

Background:

In the last years, basic research and arthroscopic surgery, have improved our understanding of shoulder anatomy and pathology. It is a fact that arthroscopic treatment of shoulder instability has evolved considerably over the past decades. The aim of this paper is to present the variety of pathologies that should be identified and treated during shoulder arthroscopy when dealing with anterior shoulder instability cases.

Methods:

A review of the current literature regarding arthroscopic shoulder anatomy, anatomic variants, and arthroscopic findings in anterior shoulder instability, is presented. In addition, correlation of arthroscopic findings with physical examination and advanced imaging (CT and MRI) in order to improve our understanding in anterior shoulder instability pathology is discussed.

Results:

Shoulder instability represents a broad spectrum of disease and a thorough understanding of the pathoanatomy is the key for a successful treatment of the unstable shoulder. Patients can have a variety of pathologies concomitant with a traditional Bankart lesion, such as injuries of the glenoid (bony Bankart), injuries of the glenoid labrum, superiorly (SLAP) or anteroinferiorly (e.g. anterior labroligamentous periosteal sleeve avulsion, and Perthes), capsular lesions (humeral avulsion of the glenohumeral ligament), and accompanying osseous-cartilage lesions (Hill-Sachs, glenolabral articular disruption). Shoulder arthroscopy allows for a detailed visualization and a dynamic examination of all anatomic structures, identification of pathologic findings, and treatment of all concomitant lesions.

Conclusion:

Surgeons must be well prepared and understanding the normal anatomy of the glenohumeral joint, including its anatomic variants to seek for the possible pathologic lesions in anterior shoulder instability during shoulder arthroscopy. Patient selection criteria, improved surgical techniques, and implants available have contributed to the enhancement of clinical and functional outcomes to the point that arthroscopic treatment is considered nowadays the standard of care.

The Glenoid Labrum

The glenoid labrum is a critical structure within the gleno-humeral joint and commonly requires treatment by the shoulder surgeon. This review presents a concise summary of the embryology, anatomy, microscopy, biomechanical properties and clinical lesions involving the glenoid labrum. This knowledge will aid the clinician in understanding its function and pathology.

The Double Bankart Bridge: A Technique for Restoration of the Labral Footprint in Arthroscopic Shoulder Instability Repair

It has been proved by many researchers in the last few years that arthroscopic capsulolabral repair is an efficient method for surgical management of anteroinferior shoulder instability. Different arthroscopic techniques using different fixation devices and constructs have been described in the literature, but the suture anchors were the most used implants to shift the inferiorly displaced capsulolabral complex and fix it to the glenoid. In the majority of these techniques, the anchors concentrate the load at specific points (e.g., at 3 or 4 interrupted points over the glenoid directly opposite the anchors) without putting direct pressure on the area of the labral footprint that is between the anchors. We describe here a technique using 2 standard suture anchors inferiorly in conjunction with a knotless suture anchor (e.g., 3.5 mm PushLock, Arthrex, Naples, FL) superiorly. No additional separate sutures or suture tapes are required other than those already loaded in the inferior 2 anchors, which are used to compress the capsulolabral complex to the glenoid in the areas between the suture anchors, producing a uniform pressure that may contribute to better healing.

Beyond the Cuff: MR Imaging of Labroligamentous Injuries in the Athletic Shoulder

Shoulder disease is common in the athletic population and may arise as a consequence of a single traumatic episode or multiple repeated events. Associated labroligamentous injuries can result in substantial disability. Specific athletic and occupational activities result in predictable injury patterns. Imaging in general and magnetic resonance (MR) imaging, in particular, are vital in establishing the correct diagnosis and excluding common mimicking conditions, to ensure timely and appropriate management. In this review, the utility of MR imaging and MR arthrography will be explored in evaluation of shoulder disease, taking into account normal variants of the labroligamentous complex. Subsequently, broad categories of labral lesions and instability, external and internal impingement, as well as nerve entrapment syndromes, will be discussed, while emphasizing their imaging findings in the clinical context and illustrating key features. More recent concepts of internal impingement and secondary subacromial impingement will also be clarified.

Predictors of functional outcomes and recurrent shoulder instability after arthroscopic anterior stabilization

PURPOSE

To investigate what factors might predict the results of arthroscopic stabilization for anterior shoulder instability.

METHODS

One hundred and forty-three patients averaging 25 (15-58) years with traumatic anterior shoulder instability who underwent arthroscopic stabilization were reviewed at a median follow-up of 81 (24-172) months. Sixty-two (56.4 %) individuals were involved in contact sport activities, and there were 40 (30 %) patients who had only one dislocation prior to having surgery. Rowe score was measured preoperatively and at follow-up.

RESULTS

Thirty-three (23.1 %) patients experienced recurrent instability 12 (1-120) months after surgery, and 15 of those underwent further surgery. There was a statistically significant lower risk of failure (p = 0.027) for patients who had a surgical procedure after only one episode of shoulder dislocation. Patients treated after the second or further episode of shoulder dislocation exhibited a mean odds ratio for failure of 3.8 (95 % confidence interval 1.2-11.6, p = 0.044) with regard to first-time dislocators. The Rowe score significantly improved from a preoperative value of 25 (5-55) to a postoperative value of 100 (40-100) (p < 0.001). A significantly higher postoperative Rowe score was found in patients older than 24 years of age at the operation (p = 0.011) and in patients with less than eight dislocations prior to surgery (p = 0.05).

CONCLUSIONS

These results suggest that better functional results following arthroscopic stabilization can be expected in patients over 24 years of age and in those with a fewer number of dislocations preoperatively. A lower rate of recurrence can be expected if the patient undergoes surgery after the first episode of dislocation.

LEVEL OF EVIDENCE

Prognostic study, Level II.

History of shoulder instability surgery

PURPOSE

The surgical management of shoulder instability is an expanding and increasingly complex area of study within orthopaedics. This article describes the history and evolution of shoulder instability surgery, examining the development of its key principles, the currently accepted concepts and available surgical interventions.

METHODS

A comprehensive review of the available literature was performed using PubMed. The reference lists of reviewed articles were also scrutinised to ensure relevant information was included.

RESULTS

The various types of shoulder instability including anterior, posterior and multidirectional instability are discussed, focussing on the history of surgical management of these topics, the current concepts and the results of available surgical interventions.

CONCLUSIONS

The last century has seen important advancements in the understanding and treatment of shoulder instability. The transition from open to arthroscopic surgery has allowed the discovery of previously unrecognised pathologic entities and facilitated techniques to treat these. Nevertheless, open surgery still produces comparable results in the treatment of many instability-related conditions and is often required in complex or revision cases, particularly in the presence of bone loss. More high-quality research is required to better understand and characterise this spectrum of conditions so that successful evidence-based management algorithms can be developed.

LEVEL OF EVIDENCE

IV.

Glenoid labrum pathology

The glenoid labrum is the fibrocartilage of the shoulder joint, anchoring the joint capsule and shoulder ligaments. Morphology varies regionally, especially in the superior and anterior region; these variants can sometimes be confused with pathological aspects. The labrum is often involved in shoulder pathology, by single trauma or, more often, repeated microtrauma. It seems logical to classify and to describe tears according to two criteria: the sector involved, and associated pain or instability. In the superior labrum, SLAP lesions are the most frequent. These combine labral lesion and lesion of the proximal insertion of the long head of the biceps brachii tendon. The most frequent form is SLAP II. They may be associated with instability or not. In the antero-inferior and postero-inferior labrum, lesions are mainly due to instability, particularly Bankart lesions (capsulolabral avulsion) anteriorly and Kim's lesion posteriorly. Circumferential labral lesions may be found in unstable shoulder. Finally, postero-superior lesions involve Walch's internal impingement: repeated contact between the deep surface of the cuff and the labrum, which takes on a degenerative aspect, with a kissing lesion of the cuff. There is no general rule for management: some labral lesions are resected and others fixed. The cause (which is usually shoulder instability), however, needs to be assessed and treated.

Identification and treatment of existing copathology in anterior shoulder instability repair

Recurrent anterior instability is a common finding after traumatic glenohumeral dislocation in the young, athletic patient population. A variety of concomitant pathologies may be present in addition to the classic Bankart lesion, including glenoid bone loss; humeral head bone loss; rotator interval pathology; complex/large capsular injuries including humeral avulsions of the glenohumeral ligaments (HAGL lesions), SLAP tears, near circumferential labral tears, and anterior labral periosteal sleeve avulsions (ALPSA lesions); and rotator cuff tears. Normal anatomic variations masquerading as pathology also may be present. Recognition and treatment of these associated pathologies are necessary to improve function and symptoms of pain and to confer anterior shoulder stability. This review will focus on the history, physical examination findings, imaging findings, and recommended treatment options for common sources of copathology in anterior shoulder instability repair.

Shoulder instability in the military

Shoulder instability is common in military populations, and this demographic represents individuals at high risk for recurrence. Surgical management is often indicated, especially in high-demand young individuals, and provides a predictable return to military duties. Accurate recognition of glenoid bone loss and other associated anatomic lesions is of importance for appropriate selection between arthroscopic capsulolabral repair and bony reconstruction procedures. A thorough understanding of underlying pathology, diagnostic testing, and available treatment options provides for optimal care of the unstable shoulder.

Clinical assessment of the glenoid labrum

BACKGROUND

The glenoid labrum is integral to shoulder stability and can be difficult to assess clinically. Whilst it is a single anatomical structure, damage to different regions results in very different clinical manifestations. A large number of provocative tests have been described, all of which initially purport to have excellent diagnostic accuracy. Clinical experience suggests that this is not the case and decision making can be difficult for the non-expert. The purpose of this study is to review the current evidence for the most commonly used tests and to provide suggestions for tests which have the most evidence for efficacy.

METHODS

The glenoid labrum was divided into anterior, superior and posterior regions. The English language literature describing labral tests was reviewed. The evidence provided by the authors and any subsequent studies was analysed.

RESULTS

Whilst a large number if tests have been described with the primary authors reporting excellent results the evidence for most is poor when later tested critically.

DISCUSSION

No single test will accurately diagnose labral pathology. The clinician must use evidence from the clinical history combined with selective use and interpretation of tests with which they are familiar.

Glenoid bone loss in the setting of an anterior labroligamentous periosteal sleeve avulsion tear

BACKGROUND

Glenoid bone loss is a factor that has been inversely associated with the success of shoulder instability repair. Recently, patients with an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion have also been identified as having a higher failure rate after surgical repair.

PURPOSE

To determine differences in the amount of glenoid bone loss and to compare demographic factors of instability in patients with and without ALPSA tears.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Over a 3-year period, all patients (N = 83) who were treated for anterior shoulder instability at a single institution were reviewed retrospectively. A total of 39 (47%) were identified as having an ALPSA lesion and 44 (53%) as having no ALPSA tear. Glenoid bone loss was determined in 2 ways: (1) radiographically by 3-dimensional computed tomography (3D CT) (humeral head digitally subtracted by 3 blinded observers) and (2) with arthroscopic techniques at the time of surgery. Demographic data such as the time from the initial instability event to advanced imaging and surgery were noted. These data were then analyzed with the Student t test to determine any significant differences between the 2 groups.

RESULTS

The patients with an ALPSA lesion had more preoperative instability events than those without (8.2 vs 3.6, respectively; P = .04). The mean glenoid bone loss measured by 3D CT was 12.7% (range, 0%-22.3%) for those with ALPSA tears versus 6.25% (range, 0%-23.1%) for those without (P = .002). The mean duration of total instability for those with ALPSA tears was 42.9 months versus 46.3 months for those without (P = .95). Lastly, the mean bone loss based on arthroscopic measures was 11.4% for patients with ALPSA tears and 4.3% for those without ALPSA tears (P = .017). From the existing magnetic resonance imaging/arthrography scans reviewed, 82% of patients could be correctly identified as having an ALPSA lesion.

CONCLUSION

Patients with anterior shoulder instability who have an ALPSA lesion have nearly twice the amount of glenoid bone loss as those with a standard Bankart tear (no ALPSA lesion). Patients with ALPSA lesions had statistically more instability events, and this may be an additional factor in either developing an ALPSA lesion or glenoid bone loss or both.

[Magnetic resonance imaging of the shoulder: impingement and instability related abnormalities--update 2013]

Magnetic resonance imaging (MRI) plays an important role in the diagnosis and differentiation of numerous shoulder abnormalities and chronic shoulder pain. Important indications for MRI are assessment of the rotator cuff and the labrocapsular complex. The assessment of the rotator cuff muscles is crucial. The value of MR arthrography is discussed. The potential benefit of MR arthrography is the accurate evaluation of subtle rotator cuff abnormalities, shoulder instability-related lesions and the assessment of pathological conditions of the long biceps tendon. The following article describes the most common pathological findings of the shoulder joint and gives a description of the relevant findings for the orthopedic shoulder surgeon. The current article represents an update of an article previously published in 2006 with the same title (Zanetti and Saupe, Radiologe 46:79-89, 2006).