Humeral avulsion of glenohumeral ligaments as a cause of anterior shoulder instability

Prospective Evaluation of Surgical Treatment of Humeral Avulsions of the Glenohumeral Ligament

BACKGROUND

Humeral avulsion of the glenohumeral ligament (HAGL) is an infrequent but significant contributor to shoulder dysfunction, instability, and functional loss.

PURPOSE

To prospectively identify patients with HAGL lesions and then conduct retrospective evaluation of the clinical history, examination findings, and surgical outcomes of these patients.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Over a 6-year period (2006-2011), patients with shoulder dysfunction and a HAGL lesion that was confirmed via magnetic resonance arthrogram (MRA) were prospectively evaluated with a minimum 2-year follow-up. Patient demographics, presentation, examination, and surgical findings were documented. Outcomes of return to activity as well as Western Ontario Shoulder Instability Index (WOSI) and Single Assessment Numeric Evaluation (SANE) scores were recorded at final follow-up. Anterior HAGL (aHAGL) lesions were repaired with a partial subscapularis tenotomy approach, while reverse (rHAGL) lesions were repaired arthroscopically.

RESULTS

Of 28 patients, 27 (96%) completed the study requirements at a mean of 36.2 months (range, 24-68 months). The sample contained 12 females (44%) and 15 males (56%), who had a mean age of 24.9 years (range, 18-34 years). The chief complaint reported was pain in 23 patients (85%), while only 4 (15%) patients complained primarily of recurrent instability symptoms. Fourteen patients (52%) had aHAGL lesions, 10 patients (37%) had rHAGL lesions, and 3 patients (11%) had combined aHAGL and rHAGL lesions. Ten patients (37%) had concomitant HAGL lesions and labral tears, whereas 17 patients (63%) had isolated HAGL lesion without labral tear. The 17 patients (63%) with aHAGL lesions or combined lesions underwent a partial subscapularis tenotomy approach, while the remaining 10 patients (37%) with rHAGL lesions underwent arthroscopic surgical repair. After surgery, WOSI outcomes improved from 54% to 88% and SANE outcomes improved from 50% to 91% ( P < .01 for both), with no reports in recurrence of instability symptoms at final follow-up.

CONCLUSION

This study demonstrated that patients with symptomatic HAGL lesions predominantly report shoulder pain and dysfunction, with few chief complaints of recurrent instability complaints. After surgery, patients showed predictable return to full activity, improvement in objective and patient-reported outcomes, and satisfaction with treatment outcome.

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.

Arthroscopic treatment of anterior shoulder instability associated with a HAGL lesion-a case series

BACKGROUND

Restoration of shoulder stability after humeral avulsion of glenohumeral ligament (HAGL) lesions can be achieved with arthroscopy, yet limited evidence exists on its benefit. We evaluated objective and subjective outcomes after arthroscopic refixation of a HAGL lesion.

METHODS

Between 2009 and 2012, 8 patients were treated arthroscopically for anterior shoulder instability associated with a HAGL lesion and invited for a follow-up examination. Radiographic assessment of joint centering and osteoarthritis, clinical assessment including Constant and Rowe scores, and complications as well as functional outcomes using the Western Ontario Shoulder Instability Index, Subjective Shoulder Value, and Simple Shoulder Test were documented.

RESULTS

Six patients were postoperatively examined at a median time of 29 months (range, 12-38). Four patients had up to 6 previous luxation events. Two patients had a concomitant labral lesion, and another 2 had an associated rotator cuff tear. Positive preoperative apprehension and relocation test results for 5 patients were negative at follow-up. No neurologic lesion was noted both before and after surgery. Shoulder motion did not improve significantly; lower internal and external rotation relative to the contralateral shoulder was reported. The Rowe score improved significantly from baseline (median score change, 65 points; P = .027), with 2 and 4 patients rating "good" and "excellent" at follow-up, respectively. Final median Constant score, Western Ontario Shoulder Instability Index, Subjective Shoulder Value, and Simple Shoulder Test scores were 77.3 points, 91.0 points, 90%, and 87.5 points, respectively.

CONCLUSION

Arthroscopic stabilization of a HAGL lesion is a safe, feasible, and reproducible technique. In our patient cohort, good shoulder stability could be achieved with high patient satisfaction.

Glenoid avulsion of the glenohumeral ligament (GAGL): a case report and review of the anatomy

Shoulder dislocations are frequently seen in the general population and can be a cause of instability. Instability can lead to debilitating symptoms and morbidity as a result of progressive damage to the shoulder. Anterior shoulder dislocations are the most frequent type of dislocations and have been studied extensively with MRI. The soft tissue Bankart lesion is the most well-known entity associated with anterior instability; however, additional structural lesions arising from traumatic events have been described in recent literature which also predispose to anterior shoulder instability. One of these lesions, the glenoid avulsion of the glenohumeral ligament (GAGL), involves avulsion of the inferior glenohumeral ligament from the glenoid and involves separation from an intact labrum. In contrast to the Bankart lesion, there has been limited discussion of the GAGL lesion in the literature and very few imaging examples. We report a case of a GAGL diagnosed on MRI and confirmed with arthroscopy. It is discussed in the context of the anatomy of the inferior glenohumeral ligament and the imaging findings.

Humeral Avulsion of the Glenohumeral Ligaments: A Systematic Review

PURPOSE

To analyze clinical outcomes, range of motion, rate of recurrence, and complications after procedures to manage shoulder instability in patients with humeral avulsion of the glenohumeral ligament (HAGL) lesions.

METHODS

A systematic review of the literature according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines with a PRISMA checklist and algorithm was performed. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase, and Google Scholar databases using various combinations of the Keywords "shoulder," "HAGL," "treatment," "lesion," "dislocation," "instability," "clinical," "outcome," "Bankart" since inception of databases to 2015 was performed. All the investigators independently extracted the following data: demographics, types of lesions and associated injuries, treatment, outcome measurements, range of motion, recurrent instability, and complications.

RESULTS

Eleven articles were included in which 42 shoulders with HAGL lesions were evaluated. Patients were assessed at a median follow-up period of 25.5 months, ranging from 12 to 54 months. The overall rate of recurrence was 0% (0 of 25) in case of surgery and 90% (9 of 10) in case of nonoperative treatment. The surgical approach was associated with lower rate of recurrence when compared with nonoperative treatment (odds ratio 0.05, 95% confidence interval 0.01 to 0.42, and P = .006). Only 2 papers reported loss of external rotation after surgery. No complications were reported after surgery. Complications after nonoperative treatment were not discussed.

CONCLUSIONS

Recognizing HAGL lesions is important to manage patients with glenohumeral instability. Patients' complaints are often nonspecific. A high index of suspicion is required in patients with prior failed shoulder surgery. HAGL lesions are often associated with other shoulder lesions. Arthroscopic or open repairs of HAGL lesions are associated with good clinical outcomes and a lower rate of recurrence compared with nonoperative treatment.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Evaluation and treatment of failed shoulder instability procedures

Management of the unstable shoulder after a failed stabilization procedure can be difficult and challenging. Detailed understanding of the native shoulder anatomy, including its static and dynamic restraints, is necessary for determining the patient’s primary pathology. In addition, evaluation of the patient’s history, physical exam, and imaging is important for identifying the cause for failure after the initial procedure. Common mistakes include under-appreciation of bony defects, failure to recognize capsular laxity, technical errors, and missed associated pathology. Many potential treatment options exist for revision surgery, including open or arthroscopic Bankart repair, bony augmentation procedures, and management of Hill Sachs defects. The aim of this narrative review is to discuss in-depth the common risk factors for post-surgical failure, components for appropriate evaluation, and the different surgical options available for revision stabilization.

Level of evidence Level V.

Hyper extension-internal rotation (HERI): A new test for anterior gleno-humeral instability

BACKGROUND

Anterior shoulder dislocation causes injury to the inferior gleno-humeral ligament (IGHL) and capsule. Clinical manoeuvres currently used to evaluate the IGHL test for, and may induce, apprehension. We developed the hyper extension-internal rotation (HERI) test to assess the IGHL and inferior capsule without causing apprehension or inducing a risk of gleno-humeral dislocation.

HYPOTHESIS

The HERI test is easy to perform and reproducible, induces no risk of gleno-humeral dislocation during the manoeuvre, and causes no apprehension in the patients.

MATERIAL AND METHODS

We studied 14 fresh cadaver shoulders. Each specimen was positioned supine with the lateral edge of the scapula on the table and the upper limb hanging down beside the table under the effect of gravity. This position produced hyperextension and internal rotation of the gleno-humeral joint. For each shoulder, the range of extension (°) was measured before and after isolated IGHL section. Then, we performed the HEIR test in 50 patients with chronic unilateral anterior gleno-humeral instability and we compared the range of extension between the normal and abnormal sides.

RESULTS

In the cadaver study, isolated IGHL section increased the angle of extension by a mean of 14.5° (11°-18°) compared to the pre-injury values. In the clinical study, the mean difference in extension angles between the normal and abnormal sides was 14.5°. The patients reported no apprehension during the HERI test.

CONCLUSION

The angle of extension increases after section or injury of the IGHL in cadaver specimens and patients, respectively. When the inferior capsule and IGHL are damaged, the angle of extension increases compared to the normal side. Lesions to these structures can be evaluated clinically by performing the HERI test.

LEVEL OF EVIDENCE

III.

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.

Factors affecting capsular volume changes and association with outcomes after Bankart repair and capsular shift

BACKGROUND

Capsular laxity is a main contributing factor in recurrent shoulder instability and is suggested to be correlated with increased capsular volume. Arthroscopic capsular shift combined with Bankart repair can reduce the capsular volume and reinforce the redundant capsule; however, as the capsuloligamentous structure has viscoelastic properties, it is possible for the shifted and tensioned capsule of the glenohumeral joint to slowly stretch out again over time, resulting in an increase in capsular volume.

PURPOSE

To analyze changes in capsular volume of the glenohumeral joint over time after arthroscopic Bankart repair and capsular shift, the factors associated with these changes, and their relevance to outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Included in this study were 105 patients (mean age, 25.8 ± 8.2 years) who underwent arthroscopic Bankart repair and capsular shift for anterior shoulder instability and computed tomography arthrography (CTA) at 3 months and 1 year postoperatively and whose various functional outcomes were evaluated preoperatively and at the last follow-up (>12 months). Among these patients, 27 also had preoperative CTA. These 27 patients were used to make comparisons between preoperative and 3-month postoperative CTA measurements, and all 105 patients were used for all other comparisons. Two raters measured the separate anterior and posterior capsular volume and cross-sectional area at the 5-o'clock position using 3-dimensional (3D) Slicer software. These measurements were subsequently adjusted for each glenoid size. The changes in capsular volume and cross-sectional area at the 5-o'clock position over time, the factors related to higher change in anterior capsular volume, and their correlation with outcomes were evaluated.

RESULTS

Three months postoperatively, the total and anterior capsular volume and anterior cross-sectional area significantly decreased; however, these values increased again at 1 year postoperatively (all P < .01). The inter- and intraobserver reliabilities of the measurements were excellent (interclass correlation coefficient = 0.717-0.945). Female sex, being an elite athlete, and more dislocations before surgery were related to a higher increase in anterior capsular volume at 1 year (all P < .05). Eight patients had redislocation, and 18 exhibited positive apprehension test postoperatively, and these patients showed significantly higher increases in anterior and total capsular volume at 1 year than did those without redislocation or positive apprehension sign (all P < .01). However, with the exception of Rowe score, a higher increase in anterior capsular volume was not related to functional outcome measures.

CONCLUSION

Surgeons should be aware of the re-increase in anterior capsular volume or restretching trait of the anterior capsule over time, even after successful arthroscopic Bankart repair and capsular shift. In this study, women, elite athletes, and those with frequent dislocations were at high risk of capsular restretching. An increase in capsular volume was related to redislocation and positive apprehension sign as well as with Rowe score.

Evaluation of Contrast Extravasation as a Diagnostic Criterion in the Evaluation of Arthroscopically Proven HAGL/pHAGL Lesions

Purpose. The validity of preoperative MRI in diagnosing HAGL lesions is debated. Various investigations have produced mixed results with regard to the utility of MRI. The purpose of this investigation is to apply a novel method of diagnosing HAGL/pHAGL lesions by looking at contrast extravasation and to evaluate the reliability of such extravasation of contrast into an extra-articular space as a sign of HAGL/pHAGL lesion. Methods. We utilized specific criteria to define contrast extravasation. We evaluated these criteria in 12 patients with arthroscopically proven HAGL/pHAGL lesion. We also evaluated these criteria in a control group. Results. Contrast extravasation occurred in over 83% of arthroscopically positive cases. Contrast extravasation as a diagnostic criterion in the evaluation of HAGL/pHAGL lesions demonstrated a high interobserver degree of agreement. Conclusions. In conclusion, extra-articular contrast extravasation may serve as a valid and reliable sign of HAGL and pHAGL lesions, provided stringent criteria are maintained to assure that the contrast lies in an extra-articular location. In cases where extravasation is not present, the “J” sign, though nonspecific, may be the only evidence of subtle HAGL and pHAGL lesions. Level of Evidence. Level IV, Retrospective Case-Control series.

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.

A large humeral avulsion of the glenohumeral ligaments decreases stability that can be restored with repair

BACKGROUND

Humeral avulsion of the glenohumeral ligaments (HAGL) has become a recognized cause of recurrent shoulder instability; however, it is unknown whether small and large HAGL lesions have similarly destabilizing effects and if large lesion repair results in restoration of stability.

QUESTIONS/PURPOSES

In a cadaver model, we evaluated the effect of small and large HAGL lesions and large HAGL lesion repair on glenohumeral ROM, translation, and kinematics.

METHODS

We measured rotational ROM, humeral head translation under load, and humeral head apex position in eight cadaveric shoulders. Each specimen was tested in 60° glenohumeral abduction in the scapular and coronal planes under four conditions: intact, small HAGL lesion (mean ± SD length, 18 ± 1.8 mm), large HAGL lesion (36.8 ± 3.6 mm), and after large HAGL lesion repair. For each condition, we measured maximum internal and external rotation with 1.5 Nm of torque; glenohumeral translation in 90° external rotation with 15- and 20-N force applied in the anterior, posterior, superior, and inferior directions; and humeral head apex position throughout ROM. Repeated-measures ANOVA was used for statistical analysis.

RESULTS

Small HAGL lesions did not change ROM, translation, or kinematics from the normal shoulder; however, these parameters changed with large HAGL lesions. Maximum external rotation and total ROM increased in the scapular (13.8° ± 9.4°, p < 0.001; 19.0° ± 16.5°, p < 0.001) and coronal (21.4° ± 10.6°, p < 0.001; 29.1° ± 22.1°, p < 0.001) planes. With anterior force, anterior-inferior translation increased in both planes (mean increase for both loads and planes: anterior: 9.1 ± 9.5 mm, p < 0.01; inferior, 5.7 ± 6.6 mm, p < 0.03). In the coronal plane, posterior and inferior translation also increased (4.9 ± 5.4 mm, p < 0.01; 7.1 ± 9.9 mm, p < 0.03; averaged for both loads). The humeral head apex shifted 3.7 ± 4.9 mm anterior (p = 0.04) and 2.8 ± 2.6 mm lateral (p = 0.004) in the scapular plane and 3.7 ± 3.4 mm superior (p = 0.006) and 4.1 ± 2.6 mm lateral (p < 0.001) in the coronal plane. HAGL lesion repair decreased ROM and translation in both planes and restored humeral head position in maximum external rotation.

CONCLUSIONS

Anterior large HAGL lesions increase ROM and glenohumeral translation. After large HAGL lesion repair, stability of the shoulder can be restored.

CLINICAL RELEVANCE

Surgeons should be aware of the possibility of HAGL lesions in patients with shoulder instability, and if large HAGL lesions are diagnosed, surgeons should consider repairing the lesions.

Prevalence of HAGL lesions and associated abnormalities on shoulder MR examination

OBJECTIVE

Humeral avulsion of the glenohumeral ligament (HAGL) is an uncommon shoulder injury. We report the prevalence of HAGL lesions and other associated shoulder injuries in a large series of shoulder MR examinations. All results were correlated with surgery.

MATERIALS AND METHODS

MR reports of 1,000 consecutive conventional shoulder MR exams performed on patients with shoulder pain were reviewed in our information system for the word HAGL. A total of 743 patients went on to surgery. There were 23 HAGL lesions reported at surgery. Those 23 examinations were reviewed retrospectively in consensus by two musculoskeletal radiologists. Scans were assessed for HAGL lesions, full or partial thickness supraspinatus, infraspinatus or subscapularis tendon tears, superior labral anterior posterior (SLAP) tears, anterior or posterior labral tears, and Hill-Sachs lesions.

RESULTS

All 23 patients had HAGL lesions at surgery. Sixteen HAGL lesions were seen on prospective MR reading and 17 HAGL lesions were seen on retrospective MR consensus reading. Six HAGL lesions were not seen on retrospective consensus reading. Sixteen patients had Hill-Sachs deformities, ten had subscapularis tendon tears, five had supraspinatus tendon tears, six had superior labral tearing, and six had anterior labral tears. The above findings were confirmed on arthroscopy.

CONCLUSIONS

In this series, there was a 1.6 % prevalence on all MR examinations, and prevalence of 2.1 % seen on MR examination for those who went to surgery. Common injuries associated with HAGL lesions are Hill-Sachs deformities and subscapularis tendon tears. Anterior labral tears were seen in only six cases despite Hill-Sachs deformities in 16 patients. In patients with Hill-Sachs deformities without anterior labral tears, one must carefully assess for the presence of a HAGL lesion.

Arthroscopic repair of a posterior bony humeral avulsion of the glenohumeral ligament with associated teres minor avulsion

Humeral avulsion of the inferior glenohumeral ligament (HAGL) has recently gained more recognition as a cause of shoulder instability. Posterior HAGL lesions, being much more infrequent than anterior disruptions, have only recently been documented as a notable cause of posterior instability. We detail the treatment of a previously unreported case of a posterior HAGL variant lesion consisting of a bony avulsion with involvement of the teres minor tendon. Arthroscopic fixation was facilitated by use of a "sheathless" arthroscopic approach with a 70° arthroscope and suture anchor.

Humeral avulsions of the inferior glenohumeral ligament complex involving the axillary pouch in professional baseball players

INTRODUCTION

Humeral avulsion of the inferior glenohumeral ligament is a rare injury in athletes and can involve different parts of the complex. Axillary pouch avulsion, in particular, has only recently been recognized in the literature, but has never been described in professional baseball pitchers.

MATERIALS AND METHODS

A retrospective review of professional baseball players presenting to our institution over 5 years was performed. Patients with Bankart lesions or fractures were excluded. Preoperative MRI was retrospectively correlated with the clinical and arthroscopic findings, as available.

RESULTS

Four professional baseball pitchers were identified, all who had axillary pouch humeral avulsions of the inferior glenohumeral ligament. There was a concomitant avulsion of the anterior band in one patient. Associated findings included labral tears (n = 2) and partial thickness tear of the rotator cuff (n = 2). Three patients ultimately had their axillary pouch avulsions repaired at most recent follow-up.

CONCLUSIONS

APHAGL lesions can be seen in overhead athletes such as baseball pitchers and should be carefully considered as a potential cause of disability. Appropriate diagnosis is important to ultimately elucidate the optimal management of these lesions.

Traumatic shoulder injuries: a force mechanism analysis-glenohumeral dislocation and instability

OBJECTIVE

Acute traumatic glenohumeral dislocation is one of the most commonly encountered shoulder injuries and can produce a complex combination of associated bony and soft-tissue injuries, the full extent of which is often initially underappreciated. The objectives of this article are to illustrate the relevant anatomy of the shoulder and provide a more intuitive understanding of the complex biomechanics of traumatic glenohumeral instability through the use of 3D modeling and animation to improve the radiologist's awareness of some of the most common injury patterns, and potentially improve the detection of associated injuries. Emphasis is placed on the most critical injuries to determine the ultimate treatment modality, and imaging recommendations are provided.

CONCLUSION

Understanding the force mechanisms responsible for traumatic glenohumeral dislocation can potentially improve detection of associated secondary injuries, which can guide more effective injury classification and ultimately direct more appropriate and timely intervention.

The effect of humeral avulsion of the glenohumeral ligaments and humeral repair site on joint laxity: a biomechanical study

PURPOSE

The aims of this cadaveric study were to assess the effect of different sizes of humeral avulsion of the glenohumeral ligament (HAGL) lesions on joint laxity and to investigate any difference between repairs with anchors placed in a juxtachondral position and repairs with anchors placed in the humeral neck.

METHODS

Glenohumeral specimens were tested on a shoulder laxity testing system with translations applied anteriorly up to 30 N, with the joint in 60° of glenohumeral abduction. Testing was conducted in neutral rotation and under 1-Nm external rotation for 5 specimen states: intact, medium HAGL lesion (4:30 to 5:30 clock-face position), large HAGL lesion (3:30 to 6:30 clock-face position), repair with juxtachondral suture anchors, and repair with humeral neck suture anchors.

RESULTS

Significant increases in translation were observed between the intact and large HAGL lesion states for neutral rotation (1.46 mm [SD, 2.33 mm] at 30 N; P = .049) and external rotation (0.81 mm [SD, 0.72 mm] at 30 N; P = .005). Significant reductions in translation were also observed between the large HAGL lesion and humeral neck repair states for neutral rotation (-1.78 mm [SD, 2.23 mm] at 30 N; P = .022) and external rotation (-0.33 mm [SD, 0.37 mm] at 30 N; P = .015).

CONCLUSIONS

Large HAGL lesions can increase the passive motion of the glenohumeral joint in both neutral and external rotation, although these differences are small and may be difficult to measure clinically. A repair using anchors placed in the humeral neck is more likely to restore the normal restraint to anterior translation than a juxtachondral repair.

CLINICAL RELEVANCE

Medium HAGL lesions are unlikely to show significant increases in joint translation, and repair of large HAGL lesions should be achieved with anchors placed in the humeral neck if possible.

Subscapularis avulsion of the lesser tuberosity in adolescents

BACKGROUND

Lesser tuberosity avulsion fractures in adolescents occur infrequently. Perhaps because of their rarity, many cases are missed on initial physical exam, imaging studies, and even diagnostic arthroscopy, leading to delay in diagnosis. Without operative intervention, these injuries may cause significant morbidity, whereas operative fixation has predictably good results. We review 6 cases and compare them to a review of the previous published cases.

METHODS

All cases of isolated lesser tuberosity avulsions in skeletally immature patients treated by the senior author (MTB) at a pediatric referral center were included. The mean follow-up was over 4 years (range, 2 to 7 y). Operative treatment consisted of a diagnostic arthroscopy to evaluate for concomitant pathology, followed by an open reattachment of the tuberosity through an incision in line with the anterior axillary fold. A lasso technique using suture anchors and sutures to loop over and hold down the fragment is our preferred method as it decreases the risk of fracture seen with fixation using screws or sutures through drill holes in the tuberosity.

RESULTS

Even with a frequent delay in diagnosis, all patients had a predictably good outcome with an average American Shoulder and Elbow Surgeons score of 97 (range, 88 to 100) and a Western Ontario Shoulder Instability Index of 94 (range, 84 to 100). The patient history, symptoms, and physical exam findings were consistent across the published cases. The prototypical patient is a male, age 13, who sustains an abduction and extension injury during sports. Anterior shoulder pain, positive belly press, and lift-off signs are frequent findings.

CONCLUSIONS

A high index of suspicion is needed to recognize this uncommon injury. History, physical exam for subscapularis function, and magnetic resonance imaging should be diagnostic. Operative treatment with a suture anchor lasso technique leads to predictably good results.

LEVEL OF EVIDENCE

Level IV therapeutic study.

Magnetic resonance imaging in glenohumeral instability

The glenohumeral joint enables tremendous range of motion at the expense of stability. Functional stability is maintained by the synchronous coordination of complex static and dynamic structures. Symptomatic glenohumeral instability most often results from injury to the inferior labral-ligamentous complex, the primary passive stabilizer of the shoulder. This article reviews the structures important in glenohumeral stabilization and illustrates their normal appearances and the abnormalities associated with anterior, posterior, and multidirectional instability. These lesions are discussed in the context of therapeutic decision making.

Spectrum of magnetic resonance imaging findings in clinical glenohumeral instability

The glenohumeral joint is the most commonly dislocated joint in the body, and anterior instability is the most common type of shoulder instability. Depending on the etiology and the age of the patient, there may be associated injuries, for example, to the anterior-inferior labro-ligamentous structures (in young individuals with traumatic instability) or to the bony components (commoner in the elderly), which are best visualized using MRI and MR arthrography. Anterior instability is associated with a Bankart lesion and its variants and abnormalities of the anterior band of the inferior glenohumeral ligament (IGHL), whereas posterior instability is associated with reverse Bankart and reverse Hill-Sachs lesions. Cases of multidirectional instability often have no labral pathology on imaging but show specific osseous changes including increased chondrolabral retroversion. This article reviews the relevant anatomy in brief and describes the MRI findings in each type, with the imaging features of the common abnormalities.

The rationale for an arthroscopic approach to shoulder stabilization

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

Magnetic resonance imaging in glenohumeral instability

The glenohumeral joint is the most commonly dislocated joint of the body and anterior instability is the most common type of shoulder instability. Magnetic resonance (MR) imaging, and more recently, MR arthrography, have become the essential investigation modalities of glenohumeral instability, especially for pre-procedure evaluation before arthroscopic surgery. Injuries associated with glenohumeral instability are variable, and can involve the bones, the labor-ligamentous components, or the rotator cuff. Anterior instability is associated with injuries of the anterior labrum and the anterior band of the inferior glenohumeral ligament, in the form of Bankart lesion and its variants; whereas posterior instability is associated with reverse Bankart and reverse Hill-Sachs lesion. Multidirectional instability often has no labral pathology on imaging but shows specific osseous changes such as increased chondrolabral retroversion. This article reviews the relevant anatomy in brief, the MR imaging technique and the arthrographic technique, and describes the MR findings in each type of instability as well as common imaging pitfalls.

Evaluation and treatment of shoulder instability

The shoulder joint has a wide range of motion as a result of a complex interplay of soft tissue and bone structures. It is also the most frequently dislocated joint in the body. Shoulder dislocations are generally classified as traumatic and nontraumatic. There are many specific causes, each of which necessitate individualized treatment modalities. Accurate diagnosis requires a careful history and physical examination. Arthroscopic surgery and advances in imaging have expanded our understanding of anatomy and pathology relevant to shoulder instability and its treatment. Surgery is the treatment of choice for recurrent traumatic instability. Surgery may also be indicated in some first-time traumatic dislocations in young contact athletes, whereas rehabilitation is the initial treatment of choice in older patients with initial instability and in those with nontraumatic dislocations. Results of arthroscopic capsulolabral repair now equal those of open capsulolabral repair and have become the surgical treatment of choice for most patients. However, in cases of recurrent instability and significant bone deficiency of either the glenoid or humeral head, open bone reconstructive procedures are often necessary to ensure successful outcomes.

Humeral avulsion of the inferior glenohumeral ligament in college female volleyball players caused by repetitive microtrauma

BACKGROUND

Humeral avulsion of the inferior glenohumeral ligament is a rare injury resulting from hyperabduction and external rotation, and it is most commonly seen with sports-related injuries, including those from volleyball. The anterior band of the inferior glenohumeral ligament is most commonly injured (93%), whereas the posterior band is infrequently injured. The axillary pouch humeral avulsion of the inferior glenohumeral ligament as a result of repetitive microtrauma has not been yet described in the English literature.

HYPOTHESIS

Humeral avulsions of the inferior glenohumeral ligaments are identifiable in volleyball players without acute injuries, and they have a unique pathologic pattern in these athletes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Four female college volleyball players with pain in their dominant shoulder and with inferior capsular laxity and/or instability—without a known history of trauma or dislocation of the same shoulder—were referred by an experienced sports medicine orthopaedic surgeon for the magnetic resonance arthrogram procedure of the same shoulder. The imaging findings were retrospectively correlated with the initial interpretation and arthroscopic findings.

RESULTS

All 4 patients had an axillary pouch humeral avulsion of the inferior glenohumeral ligament. Three had articular surface partial-thickness rotator cuff tear, and 3 had a labral tear. All were outside hitters or middle blockers who consequently performed multiple hitting maneuvers in practice and games.

CONCLUSION

Repetitive microtrauma from overhead hitting in volleyball generates forces on the inferior capsule of the shoulder joint that may cause inferior capsular laxity and subsequent failure of the humeral side of the axillary pouch portion of the inferior glenohumeral ligament.

SARL: shoulder acronyms. A review of the literature

Acronyms are words formed by taking the first initial or other parts of words from a compound term. They are designed to help communicate ideas efficiently. In the literature pertaining to shoulder surgery, a variety of acronyms have been offered for normal anatomic states, physical examination findings, pathologic conditions, surgical techniques, and outcome instruments, with new acronyms offered each year. The purpose of this article is to review and clearly define acronyms used by shoulder specialists.

Capsular lesions with glenohumeral ligament injuries in patients with primary shoulder dislocation: magnetic resonance imaging and magnetic resonance arthrography evaluation

The glenohumeral ligaments are important structures for the stability of the shoulder. They are integrated parts of the capsule and are at risk to be injured in a traumatic shoulder dislocation. The aim was to examine the prevalence of capsular ligament lesions in the acute phase and at minimum 3 weeks' follow-up after first-time traumatic shoulder dislocation. Forty-two patients aged 16-40 years were included. All patients underwent computed tomography and magnetic resonance imaging (MRI) scans shortly after the injury and MR-arthrography (MRA) at follow-up. The median time from dislocation to MRI was 7 (range 2-14) days and to MRA 30 (range 21-54) days. We found capsular ligament lesions in 22 patients (52.4%) in the acute stage and in five patients (11.9%) at follow up. Nine patients (21.4%) had a humeral avulsion of the anterior glenohumeral ligament (HAGL lesion) on MRI. Three patients (7.1%) had this lesion at follow-up. The rate of HAGL lesions in the acute stage was higher than reported previously, but the prevalence at follow-up was in keeping with earlier published studies.

Humeral avulsion of glenohumeral ligaments

Humeral avulsion of glenohumeral ligaments (HAGL) is an increasingly recognized cause of recurrent shoulder instability. HAGL lesions are the result of acute traumatic glenohumeral subluxation or dislocation. Anterior avulsion of the inferior glenohumeral ligament from the humeral neck is the more common lesion; however, posterior lesions are seen as well. Careful history and physical examination are critical in the diagnosis of HAGL lesions. MRI is the best imaging study for diagnosing these lesions. Injection of intra-articular contrast dye aids in visualization. Most HAGL lesions cause recurrent instability and require surgical repair. Arthroscopic repair with the use of accessory portals has yielded promising results. Excellent results have been achieved with open surgical management using a subscapularis incision. Mini-open techniques involve limited incision in the lower one half of the subscapularis.

Glenoid avulsion of the glenohumeral ligaments as a cause of recurrent anterior shoulder instability

Although the Bankart lesion is accepted as the primary pathology responsible for recurrent shoulder instability, recognition of other soft-tissue lesions has improved the surgical treatment for this common problem. Whereas humeral avulsion of the glenohumeral ligaments has been acknowledged as a cause of anterior shoulder instability, we have not found any reported cases of glenoid avulsion of the glenohumeral ligaments. We describe 3 cases of recurrent anterior shoulder instability due to glenoid avulsion of the glenohumeral ligaments. The avulsed ligaments were repaired to the labrum and glenoid, restoring the glenohumeral ligament-labral complex.

Posterior shoulder instability secondary to reverse humeral avulsion of the glenohumeral ligament

BACKGROUND

Posterior shoulder instability resulting from a disruption of the posterior capsular structures has been reported. We present the largest series of these injuries in the published literature, propose a definition and highlight the clinical presentation, radiological findings, and associated injuries.

MATERIALS AND METHODS

A retrospective review of a single shoulder surgeons database was performed identifying posterior instability cases associated with disruption of the posterior capsule. Chart, radiological imaging, and intra-operative findings were reviewed.

RESULTS

Nineteen patients were identified with an average age lower than the overall posterior instability group. All occurred via a traumatic mechanism, the most common being a forced cross-body adduction. The only consistent symptom was posterior joint line pain. MRI reporting was found to be only 50% sensitive, increased to 78.6% when reviewed by the treating surgeon. Associated injuries are common with 58% having a labral tear, 32% a SLAP lesion, 26% a reverse Bankart lesion, 21% a chondral injury, 21% rotator cuff injury, and 11% extension of the tear into the posterior band of the inferior glenohumeral ligament.

DISCUSSION

Disruption of the posterior capsule is a rare cause of recurrent posterior instability. There are no specific symptoms that identify the injury, though a mechanism of forced cross-body adduction should raise suspicion. Identification of the injury requires specific attention to the posterior capsule on MRI, preferably performed with the arm in slight external rotation and routine visualization of the posterior capsule via viewing from the anterior portal.

Arthroscopic latarjet procedure

Although soft tissue stabilization procedures in the shoulder yield good results, arthroscopy and radiological investigations have identified more complex soft tissue and bony lesions that can be successfully treated using a Latarjet procedure. The authors have advanced this technique to make it possible arthroscopically, thereby conferring all the benefits that arthroscopic surgery offers. This article describes how and why the arthroscopic Latarjet procedure is a valuable tool in the treatment of complex shoulder instability and how the procedure can be introduced into practice. This technique has shown excellent results at short- to mid-term follow-up, with minimal complications. As such, this procedure is recommended to surgeons with good anatomic knowledge, advanced arthroscopic skills, and familiarity with the instrumentation.

Arthroscopic alphabet soup: recognition of normal, normal variants, and pathology

The capsule, labrum, glenohumeral ligaments, and rotator cuff represent the static and dynamic stabilizers of the glenohumeral joint. Various injuries can occur to one or more of these structures during traumatic shoulder dislocation, predisposing the patient to recurrent instability. Improved understanding of shoulder anatomy and biomechanics, and advancements in arthroscopic technique led to the recognition of various pathologic lesions that may contribute to instability. The ability to identify and address these lesions during arthroscopy will allow the surgeon to more fully tailor operative treatments for each individual patient suffering from shoulder instability. Furthermore, the ability to differentiate pathologic lesions from normal anatomic variants is critical to avoid inadvertent repair that will lead to loss of normal function and worsening symptoms.

Identification and management of "floating" posterior inferior glenohumeral ligament lesions

Recurrent posterior glenohumeral instability, although a less common clinical entity than anterior instability, must be recognized and appropriately treated for a successful outcome. Pathologic findings that may need to be addressed include posterior Bankart lesions, humeral avulsion of the posterior inferior glenohumeral ligament (PIGHL), intrasubstance ligament attenuation, and combined lesions. In this review, we present 2 patients with the same pathoanatomic findings of recurrent posterior shoulder instability secondary to posterior humeral avulsion of the glenohumeral ligament with an associated posterior Bankart lesion. This combination of pathology is referred to as a "floating PIGHL" lesion. We review both patient's preoperative clinical findings and imaging studies and detail the necessary steps for a successful repair.