Anterior shoulder instability: accuracy of MR arthrography in the classification of anteroinferior labroligamentous injuries

Expert Panel on Musculoskeletal Imaging, Laur O, Ha AS, Bartolotta RJ, Avery R, Bateni CP, Chen KC, Dvorzhinskiy A, Flug J, Geannette CS, Hinkle T, Hogrefe C, Plotkin BE, Todd MJ, Chang EY. ACR Appropriateness Criteria® Acute Shoulder Pain: 2024 Update

Trauma is a predominant cause of acute shoulder pain, commonly secondary to fractures (clavicle, scapula, or proximal humerus) or soft tissue injuries (typically involving the rotator cuff, acromioclavicular ligaments, or labroligamentous complex). Radiography is the imaging modality of choice for initial assessment of acute shoulder pain and identification of potential fractures. In cases where radiographs yield normal or inconclusive results, additional imaging modalities such as ultrasound, MRI, or CT of the shoulder without contrast, or MR or CT arthrography, may be useful to diagnose the underlying pathology. These modalities aid in the detection of conditions including nondisplaced fractures, tears of the labrum and rotator cuff, as well as detailed assessment of soft tissue and bony injury following glenohumeral joint dislocation. This document presents a comprehensive review of the evidence supporting or refuting the use of various imaging modalities in diagnosing acute shoulder pain. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Glenoid Labral Articular Disruption Lesions in the Setting of First-Time Anterior Shoulder Instability

PURPOSE

To compare the clinical outcomes and rates of recurrent instability in patients after arthroscopic Bankart repair with and without glenolabral articular disruption (GLAD) lesions in the setting of first-time anterior instability events.

METHODS

This was a retrospective comparative case series of consecutive patients with GLAD lesions in the setting of first-time anterior instability events who underwent arthroscopic Bankart repair. Patients with GLAD lesions (cases) were matched at a 1:3 ratio for sex, age, body mass index, and sports participation to those without GLAD lesions (controls). Primary outcomes included postoperative range of motion (forward elevation and external rotation) and patient-reported outcomes: Subjective Shoulder Value, visual analog scale score, and Western Ontario Shoulder Instability Index. Rates of recurrent instability after primary arthroscopic stabilization were also collected. Statistical analysis was performed to compare outcomes between the control and GLAD groups, with significance set to P ≤ 0.05.

RESULTS

A total of 56 patients undergoing arthroscopic anterior stabilization between 2012 and 2020 were included for analysis, of whom 14 had GLAD lesions whereas the remaining 42 were controls. The average follow-up time from surgery in controls was 8.2 years (range, 3.1-11.7 years), whereas the average follow-up time in patients with GLAD lesions was 7.6 years (range, 3.8-11.8 years). There were no differences in postoperative forward flexion or external rotation, Subjective Shoulder Value, visual analog scale score, or Western Ontario Shoulder Instability Index. The rate of recurrent instability was found to be the same in both the control and GLAD groups (7% and 7%, respectively; P = .16).

CONCLUSIONS

Patients with GLAD lesions in the setting of first-time anterior instability had comparable patient-reported outcomes, forward flexion, and external rotation postoperatively to control patients. In addition, the presence of a GLAD lesion did not influence the rate of recurrent instability.

LEVEL OF EVIDENCE

Level IV, retrospective comparative case series.

High Sensitivity and Specificity of Magnetic Resonance Arthrography for Labral Tears, Rotator Cuff Tears, Hill-Sachs Lesions, and Bankart Lesions: A Systematic Review and Meta-analysis

PURPOSE

To compare the diagnostic value of magnetic resonance arthrography (MRA) in different shoulder lesions using arthroscopy as gold standard.

METHODS

We performed a comprehensive search in Cochrane, Scopus, PubMed, and Web of Science databases for articles that reported the diagnostic value of MRA in diagnosing labral tears, rotator cuff tears (RCTs), Hill-Sachs, and Bankart injuries. We used arthroscopic surgery as a reference standard for comparison. The quality of the studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies tool. We pooled the collected data and used Stata/MP17 to generate summary statistics.

RESULTS

We identified a total of 53 articles compromising 5,487 patients. The sensitivity and specificity for Hill-Sachs lesions were 0.94 (95% confidence interval [CI] 0.80-0.99) and 0.89 (95% CI 0.77-0.95), Bankart lesions were 0.94 (95% CI 0.89-0.97) and 0.99 (95% CI 0.90-1.00), anterior labral tears were 0.91 (95% CI 0.82-0.96) and 0.96 (95% CI 0.90-0.99), posterior labral tears were 0.74 (95% CI 0.58-0.86) and 0.98 (95% CI 0.86-1.00), superior labral tears were 0.77 (95% CI 0.62-0.88) and 0.83 (95% CI 0.54-0.95), SLAP lesions were 0.86 (95% CI 0.80-0.90) and 0.91 (95% CI 0.83-0.96), partial-thickness RCTs were 0.67 (95% CI 0.45-0.83) and 0.92 (95% CI 0.78-0.97), whereas full-thickness RCTs were 0.97 (95% CI 0.91-0.99) and 0.99 (95% CI 0.93-1).

CONCLUSIONS

In conclusion, MRA is a sensitive and specific imaging method for identifying anterior labrum lesions, full-thickness RCTs, Bankart, SLAP, and Hill-Sachs lesions, with lower accuracy in partial-thickness RCTs, both posterior and superior labrum.

LEVEL OF EVIDENCE

Level III, meta-analysis of prospective and retrospective cohort and case-control studies.

Anterior Shoulder Instability: Pre- and Postoperative Imaging

Treatment algorithms for anterior glenohumeral instability are evolving. Identification of soft tissue injuries remains important because stand-alone labrum and ligament repairs are a mainstay of primary intervention. Increasingly recognized is the importance of bone lesions, particularly the synergistic effects of bipolar bone loss in the glenoid track model. Accordingly, reporting and measurement of bone lesions is crucial to treatment planning, especially in patients with a failed Bankart repair. This review covers (1) anatomy related to anterior shoulder instability, (2) preoperative imaging assessment of soft tissue injuries, (3) postoperative imaging assessment of soft tissue injuries, (4) imaging techniques for soft tissue injuries, (5) preoperative imaging of bone injuries, and (6) postoperative imaging of bone injuries.

Utilization trends for MR arthrography of the hip and shoulder: a retrospective cross-sectional analysis of 20-year data from a tertiary care academic medical center

OBJECTIVE

The purpose of this study is to analyze changes in the utilization of MRA of the hip and shoulder at a large tertiary care academic medical center during a period of significant technological advancements over the last 20 years.

MATERIALS AND METHODS

This retrospective cross-sectional analysis identified MRA of the hip and shoulder performed at our institution over a 20-year period (2/2003-2/2023) in relation to the total number of MR hip and shoulder examinations during the same period. Patient characteristics and referring provider demographic information were extracted. Descriptive statistics and trend analysis were performed.

RESULTS

The total number of MRIs of the hip and shoulder increased overall, with small dips in 2020 and 2022. MRA of the hip increased significantly over the first 10 years of the study period (p = 0.0005), while MRA of the shoulder did not change significantly (p = 0.33). The proportion of both MRA of the hip and shoulder declined over the last 10 years (hip, p = 0.0056; shoulder, p = 0.0017). Over the same period, there was significant increase in the proportion of examinations performed at 3 Tesla versus 1.5 (p < 0.0001).

CONCLUSION

Overall, there was a downward trend in MR shoulder and hip arthrogram utilization in the second half of this 20-year study period. However, utilization varied somewhat by referring specialties and credentials. These changes are likely reflective of both improvements in image quality and evolving practice recommendations. Awareness of such trends may be valuable in ensuring appropriate patient care, as well as for anticipating the needs of a musculoskeletal radiology practice.

Management of the in-season athlete with an anterior shoulder dislocation

BACKGROUND

Management of the in-season athlete presenting with an anterior shoulder dislocation is a nuanced process that continues to be refined. Options and pathways between nonoperative and operative treatment have undergone many iterations over a century of orthopedic research and advancement. It requires an understanding of sport-specific demands and the individual athlete's goals. The orthopedic surgeon must have mastery of the natural history, treatment options, and outcomes of anterior shoulder dislocations. Balance of these factors is delicate and highly individualized for each athlete, and is why management of the in-season athlete with an anterior shoulder dislocation remains an art for the orthopedic surgeon.

MATERIALS AND METHODS

A narrative review of the literature regarding the in-season athlete with anterior shoulder dislocation was conducted of the PubMed, Embase, and Cochrane databases. The findings are summarized in this article.

RESULTS

Multiple studies have investigated management of the in-season athlete with anterior shoulder dislocation. Treatment is highly individualized for each athlete and their respective circumstances. Nonoperative treatment remains the only option for athletes that seek to return to play in the same season, however with a high risk of recurrence. Operative treatment has a track record of success in terms of returning to high level of play and lower recurrence, but would preclude a return to competition in the same season.

CONCLUSIONS

Management of the in-season athlete with anterior shoulder dislocation remains a challenging issue without consensus recommendation among shoulder surgeons. Much has been done to understand the pathology and delineate indications for nonoperative treatment and surgical management. Although recurrence and return to play rates have improved with each iteration, recurrent instability and revision surgery continue to occur at high rates. Therefore, additional work remains to optimize return to play as well as long-term outcomes for athletes.

Editorial Commentary: Magnetic Resonance Arthrogram Is More Accurate and Precise Than Conventional Magnetic Resonance Imaging for Evaluating Labral Tears After First-Time Shoulder Dislocation

Recent research shows that magnetic resonance arthrogram offers better definition of certain shoulder pathology, especially labral tears, compared with magnetic resonance imaging (MRI). Conventional MRI accuracy and precision deteriorate after 2 weeks, and few health delivery environments achieve MRI within 14 days of a shoulder dislocation. Moreover, further loss of MRI accuracy is time dependent. Although magnetic resonance arthrogram should be considered a first-line imaging study when evaluating shoulder instability more than 2 weeks after the patient's injury, one must also consider clinical value and cost-effectiveness.

A new, effective method for diagnosing GLAD lesions: the chicken-wing muscle up test

PURPOSE

We aimed to develop and evaluate a new diagnostic method, the 'chicken-wing muscle up test', to improve the accuracy of diagnosis of glenolabral articular disruption (GLAD) lesions compared to currently used clinical tests for injuries to the labrum.

METHODS

Preoperative evaluations were conducted on 85 patients undergoing arthroscopic surgery at a single center between July 2021 to July 2022. The diagnostic performance of the preoperative clinical examinations (chicken-wing muscle up test, O'Brien test, crank test, and O'Driscoll test) were validated against the findings of arthroscopic examinations.

RESULTS

12 of the 85 patients in this study had arthroscopically confirmed GLAD lesions. The chicken-wing muscle up test demonstrated significantly higher sensitivity (83.33%) for GLAD lesions than the O'Brien test (33.33%), but not the crank test (50.00%) or O'Driscoll test (25.00%), and significantly higher specificity (95.89%) than the O'Brien test (75.34%), crank test (82.19%), and O'Driscoll test (71.23%). The chicken-wing muscle up test had the largest area under the receiver operating characteristic curve (AUC = 0.896, P < 0.001; O'Driscoll test AUC = 0.543, P > 0.05; crank test AUC = 0.661, P > 0.05; O'Brien test AUC = 0.481, P > 0.05), indicating significantly better diagnostic efficacy for GLAD lesions than the other three tests.

CONCLUSIONS

The chicken-wing muscle up test is a reliable diagnostic method that improves the accuracy of diagnosis of GLAD lesions.

[Imaging of posttraumatic shoulder instability : Current concepts]

Posttraumatic instability accounts for more than 95% of all shoulder instabilities with the highest incidence in patients between 20 and 30 years of age. In this age group, lesions of the capsulolabral complex are the most common sequelae after the first shoulder dislocation. Typical acute findings are the Bankart and Perthes lesions and humeral avulsion of the glenohumeral ligament (HAGL). Chronic sequelae are anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesions, and nonclassifiable lesions with deficient anterioinferior labrum and glenohumeral ligaments. Recently, quantification of Hill-Sachs and bony Bankart lesions with glenoid defects have become the focus of interest: bipolar bone loss has emerged to be one important factor of recurrent instability that has not been addressed during the first stabilizing operation. The glenoid track concept emphasizes the importance of bipolar bone loss, where the glenoid track refers to the contact area between the humeral head and the glenoid at the end-range of motion in abduction, extension and external rotation. Any lesion of the humeral head that extends beyond the glenoid track is considered high risk for engagement of the humeral head at the glenoid margin with subsequent dislocation. Both the Hill-Sachs interval and the glenoid track can be determined using computed tomography (CT) and magnetic resonance imaging and, thus, help to define the status of the shoulder (on-track vs. off-track), which is prerequisite for planning the appropriate operative procedure. Similar tendencies also exist for posttraumatic posterior instabilities which are much rarer.

SSR white paper: guidelines for utilization and performance of direct MR arthrography

OBJECTIVE

Direct magnetic resonance arthrography (dMRA) is often considered the most accurate imaging modality for the evaluation of intra-articular structures, but utilization and performance vary widely without consensus. The purpose of this white paper is to develop consensus recommendations on behalf of the Society of Skeletal Radiology (SSR) based on published literature and expert opinion.

MATERIALS AND METHODS

The Standards and Guidelines Committee of the SSR identified guidelines for utilization and performance of dMRA as an important topic for study and invited all SSR members with expertise and interest to volunteer for the white paper panel. This panel was tasked with determining an outline, reviewing the relevant literature, preparing a written document summarizing the issues and controversies, and providing recommendations.

RESULTS

Twelve SSR members with expertise in dMRA formed the ad hoc white paper authorship committee. The published literature on dMRA was reviewed and summarized, focusing on clinical indications, technical considerations, safety, imaging protocols, complications, controversies, and gaps in knowledge. Recommendations for the utilization and performance of dMRA in the shoulder, elbow, wrist, hip, knee, and ankle/foot regions were developed in group consensus.

CONCLUSION

Although direct MR arthrography has been previously used for a wide variety of clinical indications, the authorship panel recommends more selective application of this minimally invasive procedure. At present, direct MR arthrography remains an important procedure in the armamentarium of the musculoskeletal radiologist and is especially valuable when conventional MRI is indeterminant or results are discrepant with clinical evaluation.

Clinical Outcomes of Adolescents With Anterior Shoulder Instability and Glenolabral Articular Disruption Lesions Compared With Isolated Bankart Lesions

Background

Glenolabral articular disruption (GLAD) lesions may occur in adolescents with anterior shoulder instability, resulting in articular cartilage loss and reduced functional glenoid surface area.

Purpose/Hypothesis

To compare failure rates and patient-reported outcomes (PROs) between adolescents with versus without GLAD lesions who were treated for anterior shoulder instability with arthroscopic stabilization. It was hypothesized that the comparison would yield no significant differences.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients aged ≤18 years who were treated for anterior shoulder instability with arthroscopic stabilization between 2010 and 2021 were retrospectively identified. Those patients with a GLAD lesion identified at the time of surgery were compared with patients with >2 years of retrospective follow-up who were matched to the no-GLAD cohort according to pathology and management. Demographic and patient characteristics including recurrent instability, complications, and reoperations were recorded. All patients in the GLAD cohort were contacted to obtain PRO data, including the Single Assessment Numeric Evaluation; the shortened version of the Disabilities of the Arm, Shoulder, and Hand questionnaire; and the Pediatric Adolescent Shoulder Survey. Patients were also asked about recurrent instability and additional shoulder problems.

Results

Of 35 included patients (mean age, 15.4 ± 1.6 years; 80% male), 15 patients (43%) with GLAD lesions and 26 patients without GLAD lesions were identified. Both cohorts had similar patient characteristics, number of anchors, and anchor constructs; the mean follow-up period was significantly different (GLAD vs no-GLAD, 6.9 ± 3.3 vs 3.4 ± 1.2 years, respectively; P < .001). Seven of 15 GLAD patients (46.7%) underwent loose body removal; 4 of 15 GLAD patients (26.6%) and 9 of 26 no-GLAD patients (34.6%) had recurrent subjective instability (P = .7). No significant group differences were found in PRO scores, reoperation rates (15% no-GLAD vs 20% GLAD), or percentage of patients with recurrent instability between cohorts (P > .05).

Conclusion

Adolescent patients with and without GLAD lesions treated arthroscopically for anterior shoulder instability had similar PROs and failure rates at intermediate duration of follow-up. GLAD lesions may be managed in a similar surgical manner as isolated Bankart tears in teenagers, with expectations of similar outcomes.

[Treatment strategies for traumatic anterior shoulder dislocation]

Anterior glenohumeral instability is the most frequent type of shoulder instability. This is often associated with labral and osseous lesions leading to recurrent instability. A detailed medical history, a physical examination and targeted diagnostic imaging are necessary to assess possible pathological soft tissue alterations as well as bony lesions of the humeral head and the glenoid bone. Early surgical treatment has been shown to reduce the risk of recurrence, especially in young active athletes, and can avoid secondary damage. Shoulder dislocations in older patients also require a detailed assessment and selection of treatment as persisting pain and limitation of movement can occur due to rotator cuff lesions and nerve injuries. The purpose of this article is to provide an overview of the currently available evidence and results regarding diagnostic considerations and conservative vs. surgical treatment and time to return to sport after treatment of a primary anterior shoulder dislocation.

Pilot study of the ultrasonographic examination of the intact and transected medial glenohumeral ligament in dogs

Medial glenohumeral ligament injury is commonly reported during medial shoulder joint instability in dogs. Arthroscopy is considered the gold standard procedure, but it is invasive and requires distension of the joint. Ultrasonographic examination of the medial glenohumeral ligament has been studied as a possible, less invasive alternative to arthroscopy however it has not been considered a useful method of assessment due to the interference of the probe with the pectoral muscles. The aims of this prospective analytical randomized pilot study were to develop a standardized ultrasound protocol for visualizing the canine medial glenohumeral ligament and to compare goniometry and ultrasound findings in cadaver dogs with versus without transection of the medial glenohumeral ligament. Nine adult Beagle cadavers (18 shoulders) were used. The first six shoulders were used in a preliminary study to describe an ultrasound technique to identify the medial glenohumeral ligament. Arthroscopy was performed on the remaining 12 shoulders, with six randomly selected medial glenohumeral ligaments from these shoulders, transected during the procedure. Ultrasound examination was performed after each arthroscopic procedure by an ultrasonographer blinded to the patient group. Four medial glenohumeral ligaments (67%) were correctly identified during the preliminary study. Ultrasonographic examination failed to diagnose the transection of all six medial glenohumeral ligaments in the second part of the study. No difference was observed in the ligament thickness between the dogs with and without a transected medial glenohumeral ligament. Dogs with a transected medial glenohumeral ligament had a wider articular space compared to dogs without a transected ligament (P < 0.001), and an articular space wider than 8.2 mm was discriminatory of a transected medial glenohumeral ligament in all the shoulders. In conclusion, the medial glenohumeral ligament could be identified with a medial ultrasonographic approach of the shoulder and a wider articular space can be a sign of a medial shoulder joint instability. Further studies are needed to confirm these preliminary findings in living dogs, with and without shoulder instability.

Magnetic resonance shoulder imaging using deep learning-based algorithm

OBJECTIVE

To investigate the feasibility of deep learning-based MRI (DL-MRI) in its application in shoulder imaging and compare its performance with conventional MR imaging (non-DL-MRI).

METHODS

This retrospective study was approved by the local ethics committee. Seventy consecutive patients who had been examined with both DL-MRI and non-DL-MRI were enrolled for the image quality and lesion diagnosis comparison. Another 400 patients had been examined only with DL-MRI. Their images' quality was assessed by 20 radiologists using a satisfaction survey. The Kendall W test was performed to assess interobserver agreement. The Wilcoxon test was performed to compare the image quality. For lesion diagnosis, the interobserver and interstudy agreement were evaluated by kappa analysis.

RESULTS

The scan time of DL-MRI (6 min 1 s) was nearly 50% decreased compared with that of non-DL-MRI (11 min 25 s). The image quality was higher in both PDWI (4.85 ± 0.31 for DL, and 4.73 ± 0.29 for non-DL) and T2WI (4.95 ± 0.2 for DL, and 4.74 ± 0.41 for non-DL) of DL-MRI. Good interobserver agreement was found for the image quality of all the MR sequences on both DL-MRI (Kendall W: 0.588~0.902) and non-DL-MRI (Kendall W: 0751~0.865). Both the SNRs and |CNR| were significantly higher in PDWI and T2WI of DL-MRI. High interobserver and interstudy agreements for the lesions in non-DL-MRI and DL-MRI (kappa value = 0.913 to 1.000) were observed. The results of the image quality satisfaction survey in 400 patients receiving DL-MRI in the shoulder obtained 5 scores among all the radiologists.

CONCLUSION

Shoulder DL-MRI can greatly reduce the scan time, while improve imaging quality of PDWI and T2WI compared to non-DL-MRI.

KEY POINTS

• Shoulder 2D DL-MRI can greatly reduce the whole scan time and improve imaging quality of both PDWI and T2WI compared to conventional parallel MRI. • Shoulder 2D DL-MRI could be a clinical routine with greatly improved work efficiency in the future.

Accuracy of MR arthrography in the detection of posterior glenoid labral injuries of the shoulder

OBJECTIVE

The purpose of this study is to evaluate the accuracy of MR arthrography in detecting isolated posterior glenoid labral injuries using arthroscopy as the reference standard.

METHODS

MR arthrograms of 97 patients with isolated posterior glenoid labral tears by arthroscopy and those of 96 age and gender-matched controls with intact posterior labra were reviewed by two blinded radiologists for the presence and location of posterior labral abnormalities. The sensitivity and specificity of detection of posterior labral tears were calculated as well as the prevalence of associated pathologies. Medical records were reviewed for demographics, history and direction of shoulder instability, and prior surgery.

RESULTS

Posterior labral pathology was detected by MR arthrography with sensitivities of 76% and 84% for readers 1 and 2, and a specificity of 88% for both readers. Kappa value for interreader agreement was 0.91. Twenty-two of twenty-three (96%) tears isolated to the posteroinferior quadrant on arthroscopy were correctly identified on MRI. Commonly associated pathologies included paralabral cyst (38%), humeral fracture (7%), and glenoid fracture (2%). Fifteen of ninety-seven (16%) patients with posterior tears on both arthroscopy and MRI had glenoid rim deficiency on imaging versus no patients with intact posterior labra (p < 0.001). Forty of ninety-seven (41%) patients with posterior tears on arthroscopy had a history of posterior instability versus none without posterior tears. There was no significant difference in tear length on MRI between those with a history of instability and those without (p = 0.56).

CONCLUSION

MR arthrography is accurate in detecting posterior glenoid labroligamentous injuries.

Arthroscopic Characterization, Treatment, and Outcomes of Glenoid Labral Articular Disruption Lesions

BACKGROUND

The pathoanatomy of glenoid labral articular disruption (GLAD) lesions has been inconsistently and poorly defined in the literature.

PURPOSE/HYPOTHESIS

The purpose was to characterize GLAD lesions as they pertain to the pathoanatomy of labrum, cartilage, and bony structures, and to correlate findings with patient-reported outcomes (PROs). We hypothesized that greater degrees of bony and cartilaginous involvement would correlate with worse outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All patients with a diagnosis of a GLAD lesion or a reverse GLAD (RGLAD) lesion at the time of diagnostic arthroscopy (January 2006-February 2019) were included in this study. Patients with ≥13.5% bone loss or previous ipsilateral shoulder surgery were excluded. Patient charts and operative reports/photos were used to identify the location of injury, extent of injury (labral, chondral, and bony), associated injuries, demographic factors, and treatment performed. Three injury patterns were identified: small (type 1), with no chondral defect after labral repair; large (type 2), with residual chondral defect after labral repair; and bony (type 3), with associated glenoid bone loss amenable to labral repair. Characterizations were cross-referenced to PROs at a mean follow-up of 5.5 years (range, 2.6-10.5 years): American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation, shortened version of Disabilities of the Arm, Shoulder and Hand, and patient satisfaction.

RESULTS

In total, 50 patients were included, with 40 having GLAD and 10 having RGLAD lesions (mean age, 34.7 and 33.2 years, respectively). There were 14 (35%) type 1, 22 (55%) type 2, and 4 (10%) type 3 GLAD injuries. All PROs improved without any differences in the 3 subgroups postoperatively (ASES, 95.1 vs 91.3 vs 98.8, type 1, 2, and 3, respectively). RGLAD injuries were majority type 2 (7/10; 70%) with the remainder being type 1 (3/10; 30%).

CONCLUSION

With GLAD and RGLAD injuries, 3 distinct injury patterns can be observed correlating with the presence/absence of chondral loss after labral repair or the presence of associated bone loss. This descriptive characterization can facilitate arthroscopic treatment decisions. Future large studies are needed to determine if this is prognostic in nature.

How to Report: Shoulder MRI

Magnetic resonance imaging of the shoulder is a commonly performed investigation. This article discusses the common shoulder pathologies encountered, emphasizes the key features to report, and provides examples of terminology used to describe these pathologies.

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.

Glenoid labrum articular disruption in a six-year-old child: A case report

Introduction

Traumatic anterior shoulder instability is a rare occurrence in the childhood. While glenoid labrum articular disruption itself is an uncommon condition that accompanies shoulder instability in the contact athletes, the occurrence of such lesion in a child is of extreme rarity. To the best of our knowledge, this case is the first to be reported at such a young age.

Case presentation

A six-year-old female child is presented to the clinic with a painful left shoulder and limited range of motion after a fall which was abruptly prevented by the father; hence, the child was grabbed by the arm, leaving the body to pivot around the shoulder at full force in an abduction external rotation position. Radiological studies revealed anteroinferior osteochondral fragment and a matching glenoid defect. Open surgery was performed, and the osteochondral fragment with the attached labrum was fixed using smooth K-wires.

Conclusions

Although rare, shear fractures of the anterior glenoid associated with chondral damage are possible in early childhood. However, it demands a forceful burst of abduction external rotation force which could have been avoided if the child was left to fall. The use of two K-wires via an open deltopectoral approach achieved excellent results with minimum cartilage damage.

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 GLAD Lesion: are the definition, diagnosis and treatment up to date? A Systematic Review

INTRODUCTION

Although GLAD lesions are quite common, only sporadic case reports describe surgical techniques and clinical outcomes. Even if cartilage defects can result from various pathogenic mechanisms, the resulting defect has some similarities with GLAD, and its management can be a starting point to treat both types of lesion. Aim of the present study is to find a commonly accepted definition for GLAD lesions in order to understand its pathogenesis, diagnosis and possible treatments.

METHODS

A search of PubMed (MEDLINE) database has been performed in June 2020 to identify relevant articles including a combination of the following search terms: "GlenoLabral Articular Disruption" OR "GLAD" AND "shoulder" AND "cartilage, articular".

RESULTS

Abstract evaluation included 31 articles in the full-text review. Various studies showed that the performance of MR arthrography in the detection of glenohumeral cartilage lesions, including GLAD lesions, was moderate. Different therapeutic solutions have been described. Arthroscopic debridement of the lesion and reattachment of the labrum have been often used. In case of large articular defects, the labrum could be advanced in the cartilage defect to cover it. In case of cartilage flap with reparable margins, this could be reattached with different suture constructs. Neglected GLAD lesions following a chronic trauma or shoulder instability have not been described in literature.

CONCLUSIONS

The definition of GLAD injury has changed over the time. Many authors associate this lesion with shoulder instability, with trauma in abduction and extra rotation, while Neviaser's original definition described stable shoulders following a trauma in adduction.

Imaging of shoulder instability

The shoulder enjoys the widest range of motion of all the joints in the human body, therefore requires a delicate balance between stability and motility. The glenohumeral joint is inclined to fall into two main instability categories: macro and micro. Macroinstability can be traumatic or atraumatic, with anterior or posterior dislocation of the humeral head. Microinstability falls within the broader section of acquired instability in overstressed shoulder caused by repeated joint stress. Anterior traumatic instability is the most frequent entity and a relatively common injury in young and athletic population. While shoulder instability is a clinical diagnosis, imaging impacts the patient management by detailing the extent of injury, such as capsulo-labral-ligamentous tears, fracture, and/or dislocation, describing the predisposing anatomic conditions and guide the therapetic choice. The aim of this comprehensive review is to cover the imaging findings of shoulder instability by different imaging techniques.

Anterior Instability: What to Look for

Most first-time anterior glenohumeral dislocations occur as the result of trauma. Many patients suffer recurrent episodes of anterior shoulder instability (ASI). The anatomy and biomechanics of ASI is addressed, as is the pathophysiology of capsulolabral injury. The roles of imaging modalities are described, including computed tomography (CT) and MR imaging with the additional value of arthrography and specialized imaging positions. Advances in 3D CT and MR imaging particularly with respect to the quantification of humeral and glenoid bone loss is discussed. The concepts of engaging and nonengaging lesions as well as on-track and off-track lesions are examined.

Shoulder MR Imaging and MR Arthrography Techniques: New Advances

MR imaging is the standard diagnostic modality that provides a comprehensive and accurate assessment for both osseous and soft-tissue pathologic conditions of the shoulder. This article discusses standard MR imaging and arthrography protocols used routinely in clinical practice, as well as more innovative sequences and reconstruction techniques, facilitated by the increasing availability of high-field-strength magnets and multichannel phased array surface coils and incorporation of artificial intelligence. These exciting innovations allow for a more detailed and diagnostic imaging assessment, improvements in image quality, and more rapid image acquisition.

Global Perspectives on Management of Shoulder Instability: Decision Making and Treatment

The glenohumeral joint is prone to instability. Patients with instability should have a physical examination. Imaging studies can provide additional information. Classification schemes that into account soft tissue pathology, neuromuscular control, bone loss, and activity level. An arthroscopic Bankart repair is the mainstay for unidirectional instability. Bone block procedures are indicated for patients with bone loss or a failed attempt at stabilization surgery. The arthroscopic Latarjet is a promising option for these patients. For patients with multidirectional instability, prolonged rehabilitation is indicated, followed by capsular plication or inferior capsular shift if instability is unresponsive to physical therapy.

Glossary of terms for musculoskeletal radiology

Members of the International Skeletal Society compiled a glossary of terms for musculoskeletal radiology. The authors also represent national radiology or pathology societies in Asia, Australia, Europe, and the USA. We provide brief descriptions of musculoskeletal structures, disease processes, and syndromes and address their imaging features. Given the abundance of musculoskeletal disorders and derangements, we chose to omit most terms relating to neoplasm, spine, intervention, and pediatrics. Consensus agreement was obtained from 19 musculoskeletal radiology societies worldwide.

Surgeon Agreement on the Presence of Pathologic Anterior Instability on Shoulder Imaging Studies

Background

In the setting of anterior shoulder instability, it is important to assess the reliability of orthopaedic surgeons to diagnose pathologic characteristics on the 2 most common imaging modalities used in clinical practice: standard plain radiographs and magnetic resonance imaging (MRI).

Purpose

To assess the intra- and interrater reliability of diagnosing pathologic characteristics associated with anterior shoulder instability using standard plain radiographs and MRI.

Study Design

Cohort study (diagnosis); Level of evidence, 3.

Methods

Patient charts at a single academic institution were reviewed for anterior shoulder instability injuries. The study included 40 sets of images (20 radiograph sets, 20 MRI series). The images, along with standardized evaluation forms, were distributed to 22 shoulder/sports medicine fellowship-trained orthopaedic surgeons over 2 points in time. Kappa values for inter- and intrarater reliability were calculated.

Results

The overall response rate was 91%. For shoulder radiographs, interrater agreement was fair to moderate for the presence of glenoid lesions (κ = 0.49), estimate of glenoid lesion surface area (κ = 0.59), presence of a Hill-Sachs lesion (κ = 0.35), and estimate of Hill-Sachs surface area (κ = 0.50). Intrarater agreement was moderate for radiographs (κ = 0.48-0.57). For shoulder MRI, interrater agreement was fair to moderate for the presence of glenoid lesions (κ = 0.44), glenoid lesion surface area (κ = 0.35), Hill-Sachs lesion (κ = 0.33), Hill-Sachs surface area (κ = 0.28), humeral head edema (κ = 0.41), and presence of a capsulolabral injury (κ = 0.36). Fair agreement was found for specific type of capsulolabral injury (κ = 0.21). Intrarater agreement for shoulder MRI was moderate for the presence of glenoid lesion (κ = 0.59), presence of a Hill-Sachs lesion (κ = 0.52), estimate of Hill-Sachs surface area (κ = 0.50), humeral head edema (κ = 0.51), and presence of a capsulolabral injury (κ = 0.53), and agreement was substantial for glenoid lesion surface area (κ = 0.63). Intrarater agreement was fair for determining the specific type of capsulolabral injury (κ = 0.38).

Conclusion

Fair to moderate agreement by surgeons was found when evaluating imaging studies for anterior shoulder instability. Agreement was similar for identifying pathologic characteristics on radiographs and MRI. There was a trend toward better agreement for the presence of glenoid-sided injury. The lowest agreement was observed for specific capsulolabral injuries.

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.

Small KM, Adler RS, Shah SH, Roberts CC, Bencardino JT, Appel M, Gyftopoulos S, Metter DF, Mintz DN, Morrison WB, Subhas N, Thiele R, Towers JD, Tynus KM, Weissman BN, Yu JS, Kransdorf MJ. ACR Appropriateness Criteria® Shoulder Pain-Atraumatic

Shoulder pain is one of the most common reasons for musculoskeletal-related physician visits. Imaging plays an important role in identifying the specific cause of atraumatic shoulder pain. This review is divided into two parts. The first part provides a general discussion of various imaging modalities (radiographs, arthrography, nuclear medicine, ultrasound, CT, and MRI) and their usefulness in evaluating atraumatic shoulder pain. The second part focuses on the most appropriate imaging algorithms for specific shoulder conditions including: rotator cuff disorders, labral tear/instability, bursitis, adhesive capsulitis, biceps tendon abnormalities, postoperative rotator cuff tears, and neurogenic pain. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Amini B, Beckmann NM, Beaman FD, Wessell DE, Bernard SA, Cassidy RC, Czuczman GJ, Demertzis JL, Greenspan BS, Khurana B, Lee KS, Lenchik L, Motamedi K, Sharma A, Walker EA, Kransdorf MJ. ACR Appropriateness Criteria® Shoulder Pain-Traumatic

Traumatic shoulder pain is pain directly attributed to a traumatic event, either acute or chronic. This pain may be the result of either fracture (the clavicle, scapula, or proximal humerus) or soft-tissue injury (most commonly of the rotator cuff, acromioclavicular ligaments, or labroligamentous complex). Imaging assessment of traumatic shoulder pain begins with conventional radiography and, depending on physical examination findings, will require MRI or MR arthrography for assessment of soft-tissue injuries and CT for delineation of fracture planes. Ultrasound excels in assessment of rotator cuff injuries but has limited usefulness for assessment of the deep soft-tissues. CT angiography and conventional arteriography are helpful for assessment of vascular injury, and bone scintigraphy can be used in assessment of complex regional pain syndrome after traumatic shoulder injury. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Concurrent Primary Repair of a Glenoid Labrum Articular Disruption and a Bankart Lesion in an Adolescent: A Case Report of a Novel Technique

Glenoid labrum articular disruption (GLAD) lesions are an uncommon concomitant injury associated with labral tears, occurring in 1.5-2.9% of cases. In previous reported cases, the articular lesion is debrided during repair of the labral injury, which may predispose patients to osteoarthritis, a longitudinal complication seen in articular debridement of the hip. We report the case of a 15-year-old healthy adolescent male swimmer who sustained a labral injury with a concomitant GLAD lesion. During operative management, three Polyetheretherketone (PEEK) SutureTaks were placed on the glenoid. #2 FiberWire was used to imbricate capsular tissue, passed beneath the labrum, and was then subsequently advanced through the fibrous rim of the displaced cartilage flap/GLAD lesion at the site of each suture anchor. This construct restored tension to the anterior band of the inferior glenohumeral ligament, recreated the anteroinferior labral bumper, and effectively reduced the cartilage flap/GLAD lesion to the anterior inferior glenoid. By six months postoperatively, the patient demonstrated near-normal function with full range of motion and evidence of a stable construct on MRI. Unlike previously described cases, this is the first report of a hybrid technique that simultaneously performed a primary repair of both labral and articular injuries without the use of additional implants for the articular lesion. Primary repair of the labral and articular lesions should provide longitudinal benefit to the patient by reducing the risk of developing glenohumeral osteoarthritis.

Magnetic Resonance Arthrographic Demonstration of Association of Superior Labrum Anterior and Posterior Lesions With Extended Anterior Labral Tears

OBJECTIVE

The objective of this study was to evaluate retrospectively the full extent of anterior labral tear and associated other labral tears on magnetic resonance arthrographic images in patients with anterior shoulder instability.

MATERIALS AND METHODS

One hundred ten magnetic resonance arthrography images with anterior labral tear were retrieved from the database of the Radiology Department. Two skeletal radiologists, one with 15 years of experience and the other with 5 years of experience analyzed the images in random order. Approval for the study was granted by the Ethics Committee. Statistical analyses were performed using SPSS software.

RESULTS

The most common localization of the labral lesions was at the anterior-inferior part of the glenoid labrum (22.7%). The anterior labral tears were commonly associate with superior labrum anterior and posterior (SLAP) lesions (45%). The most common type of SLAP lesion was type V (23.6%). Superior Labrum Anterior and Posterior type V lesion was more often detected in patients with Bankart lesion (27.7%, P = 0.043).

CONCLUSIONS

Isolated anterior labral tears are less than expected. In majority of the cases, a distinct tear at a different site of the labrum accompanies the anterior labral tear. Massive anterior labral tears are mostly seen together with SLAP lesions.

MR arthrographic characterization of posterior capsular folds in shoulder joints

METHODS:

This was a retrospective study of 604 consecutive shoulder MR images and MR arthrograms obtained from April 2010 to January 2018. Extension in the vertical-oblique plan of the posterior synovial fold on MR arthrography was identified according to the posterosuperior, posteroinferior, superoposterior, and inferoposterior portions. The morphologies of the posterior synovial folds on MR arthrography were divided three subtypes. Morphologic appearances of the posterior labrocapsular complex on conventional MR images were described with four subtypes.

RESULTS:

A posterior synovial fold in the shoulder joint was identified in 35 of 604 (5.8%) MR arthrography patients. 8 of 35 posterior synovial fold identified on MR arthrography were confirmed at arthroscopy. The most common MR arthrographic type of the posterior synovial fold was triangular-this was detected in 17 of 35 (48.6%) patients. The most common MRI morphology of the posterior labrocapsular complex was doubled posterior labrum. This was detected in 15 of 35 (42.9%) patients. 17 % of patients with posterior synovial folds who were diagnosed with MR arthrography had normal MRI features. The most common localization of the posterior synovial fold was posterosuperior and posteroinferior portions of the posterior labrocapsular structures. The mean of the shortest distance between the posterior synovial fold and the posterior labrum was significantly higher in the positive arthroscopic synovial fold group than in the negative arthroscopic synovial fold group (p = 0.047).

CONCLUSION:

Posterior synovial folds, normal capsular anatomic variants, are seen rarely on MR arthrography, and tend to be in the posterosuperior and posteroinferior portions of the posterior capsule. Some types of the posterior synovial fold can mimic a posterior labral tear in conventional MRI.

ADVANCES IN KNOWLEDGE:

On a direct MR arthrographic image, a posterior capsular synovial fold may be a normal anatomic variant. A fold is more commonly occur in the posterosuperior and posteroinferior capsular portions. The results of our study may allow differentiation of normal variations from abnormalities in patients with symptomatic shoulder joint.

Traumatic Anterior Instability: Treatment Options for Initial Instability

Because of the lack of bony restraints and minimal articular contact, the glenohumeral joint can attain significant range of motion; however, this results in the propensity for instability. The most generic form of instability, traumatic anterior instability, reliably produces a series of pathoanatomic findings. While reliable, these findings contribute to the complexities of caring for patients after an initial instability event. Numerous studies have examined this issue and determined that careful consideration of patient factors can guide successful treatment, whether it be surgical or nonsurgical, after initial instability. Such forms of treatment have shown to provide a good functional outcome and decreases morbidity. To be able to provide successful treatment requires a thorough understanding of the pathoanatomic of an instability event and the intricacies of the evaluation of a patient after an initial instability event.

Management of the First-time Traumatic Anterior Shoulder Dislocation

Traumatic anterior dislocation of the shoulder is one of the most common directions of instability following a traumatic event. Although the incidence of shoulder dislocation is similar between young and elderly patients, most studies have traditionally focused on young patients due to relatively high rates of recurrent dislocations in this population. However, shoulder dislocations in older patients also require careful evaluation and treatment selection because they can lead to persistent pain and disability due to rotator cuff tears and nerve injuries. This article provides an overview of the nature and pathology of acute primary anterior shoulder dislocation, widely accepted management modalities, and differences in treatment for young and elderly patients.

Editorial Commentary: Are Shoulder Glenoid Labral Teardrop Lesions Reasons for Surgeons to Cry?

In the world of glenoid labral chondral injuries, perhaps the most recognizable by magnetic resonance imaging is the "teardrop" version, and the glenoid labral teardrop lesion is the glenoid chondral lesion most frequently associated with 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.

Imaging of the Unstable Shoulder

Background:

Unstable shoulder can occur in different clinical scenarios with a broad spectrum of symptoms and presentations: first-time (or recurrent) traumatic acute shoulder anterior dislocation or chronic anterior instability after repeated dislocations.

Imaging in unstable shoulder is fundamental for choosing the right treatment preventing recurrence.

The goal of imaging depends on clinical scenario and patient characteristics.

Method:

Careful selection and evaluation of the imaging procedures is therefore essential to identify, characterize and quantify the lesions. Proper imaging in unstable shoulder cases is critical to the choice of treatment to prevent recurrence, and to plan surgical intervention.

Results:

In acute setting, radiographs have to roughly detect and characterize the bone defects present. At about 7 days, it is recommended to perform a MR to demonstrate lesions to labrum and/or ligaments and bone defects: in acute setting, the MRA is not necessary, because of effusion and hemarthrosis that behave as the contrast medium.

In recurrence, it is fundamental not only to detect lesions but characterize them for planning the treatment. The first study to do is the MRI (with a magnetic field of at least 1.5 Tesla), and if possible MRA, above all in younger patients. Then, on the basis of the pathologic findings as bipolar lesion or severity of bone defects, CT can be performed. PICO method on 2D or 3D CT is helpful if you need to study a glenoid bone loss, with the “en face view” of glenoid, while a 3D CT reconstruction with the humeral head “en face view” is the gold standard to assess an Hill-Sachs lesion.

Conclusion:

The clinical diagnoses of anterior shoulder instability can be different and acknowledgement of imaging findings is essential to guide the treatment choice.

Imaging features are quite different in chronic than in acute scenario. This requires appropriate indications of many different imaging techniques.

Evaluation of Posterosuperior Labral Tear with Shoulder Sonography After Intra-articular Injection: A Case Series

Detection of a posterior glenoid labral lesion can be challenging. Clinicians may overlook this diagnosis because of its vague symptoms, unlike rotator cuff tear or adhesive capsulitis. Together with magnetic resonance (MR) imaging, shoulder MR arthrography is considered the imaging method of choice for the detection of posterior glenoid labral lesions. However, MR arthrography is associated with high cost and low accessibility, and to circumvent these shortcomings, efforts are being made to use sonography (US). However, prior experience in shoulder US is required to evaluate glenoid labrum using US because glenoid labrum is not located superficially and is surrounded by the rotator cuff musculature. There were a few studies that reported the potential for arthrosonography in finding the tear of anterior glenoid labrum and rotator cuff. Until now, however, there was no report regarding arthrosonography in posterosuperior glenoid labral tear and its efficacy and potential for overcoming the limitations of conventional US. In this report, we described 3 cases with posterosuperior glenoid labral tear that were not diagnosed by conventional US but by arthrosonography. In addition, the authors also present their history, physical examinations, and response to treatment, which may be helpful in the diagnosis of posterosuperior glenoid labral tear.

Imaging of shoulder instability

This extended review tries to cover the imaging findings of the wide range of shoulder injuries secondary to shoulder joint instability. Usefulness of the different imaging methods is stressed, including radiography, computed tomography (CT) and magnetic resonance. The main topics to be covered include traumatic, atraumatic and minor instability syndromes. Radiography may show bone abnormalities associated to instability, including developmental and post-traumatic changes. CT is the best technique depicting and quantifying skeletal changes. MR-arthrography is the main tool in diagnosing the shoulder instability injuries.

Unclassified MR arthrography pattern evaluation in patients with episodes of recurrent antero-inferior shoulder dislocation

PURPOSE

To evaluate prospectively the incidence of unclassifiable MR arthrography patterns of glenoid anterior-inferior labrum lesions, in patients with at least two episodes of recurrent antero-inferior shoulder dislocation.

MATERIALS AND METHODS

The MR shoulder Arthrography images of 36 patients, with at least two episodes of recurrent antero-inferior dislocation, were prospectively evaluated, during a period between November 2015 and Mai 2016. All patients were contacted after 6 months of the MR arthrography to evaluate their course of treatment. The MR arthrography images were analyzed by two radiologists, respectively with 5 and 15 years of experience in musculoskeletal radiology.

RESULTS

36 cases of unclassifiable MR arthrography pattern of the anterior-inferior glenoid labrum were evaluated: in 13 out 36 cases (36.1%), the glenoid labrum has been described as "oedematous and swollen"; in 19 out 36 cases (52.8%), it has been described as "smooth" (not hypoplastic); in 4 out 36 cases (11.1%), it has been described as degenerated.

CONCLUSION

The unclassifiable MR arthrography patterns of fibrocartilage glenoid lesions after episodes of recurrent antero-inferior dislocation are commons. The unclassifiable MR arthrography patterns require a careful consideration, in order to improve the diagnostic and therapeutic multidisciplinary approach.

Adhesive Capsulitis of the Shoulder Joint: Value of Glenohumeral Distance on Magnetic Resonance Arthrography

OBJECTIVE

To evaluate the usefulness of glenohumeral distance (GHD) on axial images of magnetic resonance (MR) arthrography for diagnosis of adhesive capsulitis and to compare this finding with previously reported classic MR arthrographic findings of adhesive capsulitis.

MATERIALS AND METHODS

Our study was approved by the institutional ethical review board of our institute. We evaluated 41 patients (M-F, 35:6; mean age, 46 years; adhesive capsulitis, 21; no adhesive capsulitis, 20) who underwent MR arthrography. Two radiologists measured GHD, width of the axillary recess, and capsular thickness in consensus. The GHD was measured from the subchondral bone of the glenoid fossa to the subchondral bone of the humeral head at the level of the midline of the humeral head. Glenohumeral distance (anterior, middle, posterior, and mean), width of the axillary recess, and capsular thickness (anterior, posterior, and mean) were compared in the adhesive capsulitis and no adhesive capsulitis groups using the Mann-Whitney U test.

RESULTS

The mean GHD of the no adhesive capsulitis group was longer than that of the adhesive capsulitis group. The length differences were statistically significant (P < 0.05). The mean width of the axillary recess of the no adhesive capsulitis group was significantly wider than that of the adhesive capsulitis group (P < 0.001). The mean capsular thickness of the no adhesive capsulitis group was significantly thinner than that in the adhesive capsulitis group (P = 0.001).

CONCLUSIONS

A decreased GHD on MR arthrography can be another useful feature to diagnose adhesive capsulitis in addition to previously presented radiologic features such as capsular thickening and reduced axillary recess capacity.

Is clinical evaluation alone sufficient for the diagnosis of a Bankart lesion without the use of magnetic resonance imaging?

BACKGROUND

Imaging modalities such as magnetic resonance arthrogram (MRA) offer great utility in diagnosing Bankart lesions but they are associated with a high degree of intra and interobserver variability. This study aims to evaluate the diagnostic accuracy of clinical evaluation and imaging modalities in Bankart lesions such as magnetic resonance imaging (MRI) and MRA of the shoulder.

METHODS

Between February 2004 to January 2015, a retrospectively review of the surgical records at a tertiary hospital identified a total of 250 patients treated with a shoulder arthroscopy for Bankart repair. All patients were thoroughly investigated preoperatively in which a detailed history were obtained, relevant physical examinations were performed (Load and Shift/Anterior Apprehension test) and pre-operative radiographs taken. Some patients subsequently underwent either an MRI or an MRA scan if the initial clinical evaluation was equivocal.

RESULTS

Anterior Shoulder Apprehension test and the Load and Shift test identified 214 of 227 Bankart tears, with a sensitivity of 94% [95% confidence interval (CI), 90-97%]. MRI correctly identified 23 of 26 Bankart tears, with a sensitivity of 89% (95% CI, 70-98%). Out of the five superior labrum anterior-posterior (SLAP) tears identified on MRI, only three were confirmed during arthroscopic surgery. MRA correctly identified 84 of 89 Bankart tears, for a sensitivity of 94% (95% CI, 87-98%).

CONCLUSIONS

In our study, we report that clinical evaluation with focused history-taking and anterior apprehension, load and shift clinical examination can diagnose anterior shoulder instability as reliably as MR imaging. For patients with equivocal clinical findings, MR imaging can aid in the diagnosis.