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

MR imaging of shoulder instability injuries in the athlete

Lesions leading to glenohumeral instability may result from acute trauma, atraumatic laxity, or repetitive microtrauma. Athletic activities, especially overhead throwing, may lead to a series of lesions involving the stabilizing structures of the shoulder. The resultant injuries and pathomechanics leading to shoulder symptoms can be classified as primary disease, primary instability, acute traumatic instability, and posterosuperior impingment syndrome. MR imaging with or without intrarticular or intravenous injection of contrast material, along with clinical examination and stress testing, provides valuable preoperative assessment.

Shoulder: labrum and bicipital tendon

Shoulder instability can be due to a single, acute traumatic event, generalized joint laxity, or repeated episodes of microtrauma. The later occurs in the throwing athlete. The most common lesion involving the labrum is the anterior inferior labral tear, associated with capsuloperiosteal stripping (classic Bankart lesion). A number of variants of the Bankart lesion have been described recently and include the ALPSA lesion, SLAP lesion, and HAGHL lesion, among others. Lesions of the long head of the biceps tendon can be seen in isolation (tears, tendinosis, dislocation) or in association with rotator cuff and labral lesions. Conventional MR and MR arthrography have been extensively used for the preoperative diagnosis of these lesions, with reportedly good accuracy. An understanding of the normal anatomy and biomechanics of the shoulder joint is essential for proper interpretation of the MRI manifestations of these conditions.

Age-related changes of the glenoid labrum in normal shoulders

A growing number of labral changes are described in the literature. The purpose of this study was to evaluate the glenoid and labrum of normal shoulders at different ages and characterize any apparent age-dependent changes. We analyzed 32 normal cadaveric shoulders with a mean age of 57 years (range, 18-89 years). There were 22 male and 10 female cadavers, with 14 right and 18 left specimens. The shoulders were studied macroscopically, histologically, and radiologically. The radiologic evaluation consisted of an analysis of the subchondral mineralization of the glenoid with the use of computed tomographic osteoabsorptiometry. Macroscopically, there were no statistically significant differences among the age groups. Histopathologically, the labrum showed a significant qualitative and quantitative increase (P <.01) in lesions across all regions with increasing age. In younger individuals, lesions at the 12-o'clock position were the most prevalent, with the incidence increasing with age. The anterosuperior position was the region with the next highest prevalence. This was also the area of the highest stress distribution on the glenoid. Our studies demonstrated clear histopathologic changes of the glenoid labrum that are significantly age-related at specific sites. The earliest changes are seen close to the area of highest stress distribution of the glenoid, which could explain the progressive labral changes with increasing age. Arthroscopically detected changes of the glenoid labrum should be evaluated in the context of age-related changes in normal shoulders.

Capsular elongation in shoulders with recurrent anterior dislocation. Quantitative assessment with magnetic resonance arthrography

BACKGROUND

Elongation of the shoulder capsule is often noticed on arthrograms or during surgery in shoulders of patients who have experienced recurrent anterior dislocations.

HYPOTHESIS

We can quantify the elongation of the capsule in shoulders with recurrent anterior dislocations by using magnetic resonance arthrography.

STUDY DESIGN

Retrospective review of prospectively collected data.

METHODS

Twelve patients with unilateral recurrent anterior shoulder dislocations were enrolled in this study. Magnetic resonance images in the axial and coronal oblique planes were obtained from both shoulders (involved and uninvolved sides) after 10 ml of gadolinium/saline solution was injected into the glenohumeral joint. The length of the anteroinferior, inferior, and posteroinferior portions of the capsule was measured by using image analyzing software and normalized to the humeral head diameter.

RESULTS

The anteroinferior capsule was significantly elongated in the involved shoulder at 4 mm (16% elongation) and 10 mm (19% elongation) superior to the inferior margin of the glenoid. The inferior capsule was also significantly elongated in the involved side both at the center (12% elongation) and at 4 mm anterior to the center of the glenoid (29% elongation). The posteroinferior capsule did not show any significant elongation.

CONCLUSIONS

The anteroinferior and inferior portions of the shoulder capsule are elongated an average of 19% in shoulders with recurrent anterior dislocation.

Arthroscopic stabilization of anterior shoulder instability: a review of the literature

The treatment of anterior glenohumeral instability has been a topic of debate in the recent literature. Current surgical management of shoulder instability has included a variety of open and arthroscopic procedures. Open techniques for anterior reconstruction have been quite successful in preventing recurrent dislocations and continue to be the gold standard of care. In an attempt to address some of the disadvantages associated with open procedures, arthroscopic stabilization procedures have been developed. Arthroscopic capsuloligamentous repair presumably has clear advantages including better cosmesis, decreased perioperative morbidity, and a possible decrease in the loss of external rotation. Advances in arthroscopic instrumentation and improved arthroscopic techniques have increased the popularity of arthroscopic stabilization. The art of diagnosing the anatomic pathology associated with instability and proper patient selection continues to evolve. Most previous reports of arthroscopic stabilization have included small numbers of patients, variable patient pathology, and a variety of surgical techniques, making comparisons between stabilization procedures difficult. Arthroscopy can be valuable in both the confirmation of the degree and severity of the instability and to correct the pathoanatomy responsible for the instability.

Humeral avulsions of the glenohumeral ligament: imaging features and a review of the literature

OBJECTIVE

We describe the radiologic findings of the humeral avulsion of the glenohumeral ligament (HAGL lesion) and its commonly associated injuries.

MATERIALS AND METHODS

A retrospective review of six cases of HAGL lesion diagnosed at our institution from October 1996 to February 2001 was performed. We reviewed the radiology reports, radiologic examinations, medical records, and operative notes. All patients had undergone radiography, and four patients had undergone MR imaging of the shoulder before diagnostic arthroscopy.

RESULTS

All the patients were men who ranged in age from 19 to 41 years (mean, 26 years). Four patients (67%) had an anterior shoulder dislocation. Three of the HAGL lesions (50%) were detected on radiologic examinations, either by radiography or MR imaging. One patient had a bony HAGL. All patients had associated injuries. The most common associated abnormalities were osteochondral injury of the humeral head (n = 3), rotator cuff tear (n = 3), Bankart lesion (n = 3), Hill-Sachs lesion (n = 2), avulsion of the middle glenohumeral ligament (n = 1), partial tear of the biceps brachii tendon (n = 1), and comminuted fracture of the clavicle (n = 1).

CONCLUSION

With an incidence of 7.5% and 9.4% in two large series of patients, the HAGL lesion is an important cause of anterior instability of the glenohumeral joint. The majority (68%) of patients with an HAGL lesion have associated injuries.

The unstable shoulder in the adolescent athlete

Shoulder dislocation and subluxation occur frequently in athletes, with peaks in the second and sixth decades. The majority of traumatic dislocations are in the anterior direction. The most frequent complication of shoulder dislocation is recurrence--a complication that occurs much more often in the adolescent population. The dynamic (muscular) and static (predominantly capsuloligamentous and labral) restraints to shoulder instability are now well defined. Recent surgical procedures for shoulder instability have become less interventional and have focused on restoring disrupted static restraints. The aim of rehabilitation is to enhance the dynamic muscular and proprioceptive restraints to shoulder instability.

Thermal capsulorrhaphy to treat shoulder instability

The contemporary therapeutic approach of glenohumeral instability is directed at the restoration of anatomy. Thermal capsular modification to treat shoulder instability is a relatively recent modality. Early successful clinical applications have led to a wide use of this low demanding technique. Currently, however, the indications for thermal capsulorrhaphy are defined poorly, clinical outcome has not been shown to be superior to conventional stabilization procedures, and long-term effects on joint biology and mechanics are not known. Based on a critical review of the literature and personal clinical experience, the authors conclude that additional experimental and clinical investigations are necessary to add this procedure to the accepted modalities applied for the treatment of shoulder instability.

Interplay of the static and dynamic restraints in glenohumeral instability

Anterior glenohumeral instability is a common, yet complicated orthopaedic disorder. During the past few years, basic science research has improved the understanding of the glenohumeral joint stabilizing systems. The current authors review new contributions specifically detailing study of the interplay between the static and dynamic restraints. Simulation of the shoulder muscles in a recent study also has manifested the powerful contribution of the joint reaction force to concavity-compression. Continued advances, such as these, will improve the understanding, and allow better outcome, in treatment of glenohumeral instability.

Preoperative magnetic resonance imaging diagnosis of the floating anterior inferior glenohumeral ligament

Approximately a century ago, labral avulsion from the glenoid was described as a source of recurrent anterior shoulder dislocation. Since then, the significance of other origins of shoulder instability has been a controversial issue. Cadaveric dissection, biomechanical evaluation, and surgical observation have led to the discovery of additional pathologic conditions associated with glenohumeral instability that must be properly identified and addressed for operative success. Recently, several authors have emphasized the importance of lesions of the glenohumeral ligament as a cause of post-traumatic shoulder instability. One such condition is bipolar avulsion of the anterior inferior glenohumeral ligament (AIGHL), or floating AIGHL. In previous reports, this finding has only been identified during surgery. We present a case of traumatic anterior shoulder dislocation in which a preoperative diagnosis of floating AIGHL was made by magnetic resonance imaging. Recognition of this rare lesion before surgical intervention is advantageous for appropriate preoperative planning and management of patients with posttraumatic anterior glenohumeral instability.

Sports-related injuries of the shoulder: instability

With current technology a properly conceived imaging strategy can demonstrate instability lesions in the athlete. Plain radiographs can diagnose acute dislocations and assess successful reductions. In addition, plain radiographs can demonstrate Hill-Sachs and, more importantly for instability, osseous Bankart lesions. In the acute setting, conventional MRI nicely demonstrates labral Bankart, ligamentous. and tendonous injuries that result from dislocations and can lead to instability. In the setting of chronic instability, MR arthrography best evaluates these lesions. In the postoperative shoulder, muitislice CT arthrography may be the modality of choice, but further investigation is needed. If large series validate multislice CT arthrography for the evaluation of postoperative instability lesions, this technique may become widely used in athletes and in other populations where recurrent instability is a problem. Other imaging strategies may also find an increasing central role in evaluating shoulder instability lesions. Indirect MR arthrography, for example, may have a role in assessing these lesions in athletes . Another intriguing technology for this application is the development of high field (0.5 Tesla or greater) open magnets. In such a setting, physiological relationships in the shoulder with motion and stress may be evaluated. Such imaging may farther illuminate our understanding of the stable and unstable shoulder. Unfortunately, with all imaging modalities, whether widely used or experimental, outcomes data is Lacking. How do the various imaging modalities and strategies affect patient outcome? The answer is unknown and needs to be answered before a definitive patient work-up for shoulder instability can be established.

Advances in the management of traumatic anterior and atraumatic multidirectional shoulder instability

Dislocation of the shoulder is a common and often disabling injury to an athlete. Most shoulder dislocations are traumatic in origin, occur in the anterior direction and result in stretching and detachment of the anterior capsule and labrum. The most frequent adverse sequel of shoulder dislocation is recurrence--an event that occurs most commonly in active individuals and less frequently with age. In the past, many operative procedures failed to address the anatomical disruptions of shoulder instability. Recently, an enhanced understanding of shoulder instability pathoanatomy and significant technological advances have resulted in surgical procedures for shoulder instability that are less interventional and have focused on restoring disrupted static constraints.

Prospective evaluation of arthroscopic stabilization of acute, initial anterior shoulder dislocations in young athletes. Two- to five-year follow-up

From March 1992 to November 1998, 57 patients sustained 58 acute, initial, traumatic anterior shoulder dislocations at the United States Military Academy. Six patients selected nonoperative treatment. Three patients underwent primary open repair after diagnostic arthroscopy revealed no Bankart lesion amenable to repair with the bioabsorbable tissue tack. The remaining 48 patients with 49 anterior dislocations were treated with arthroscopic primary repair. There were 45 men and 3 women with an average age of 20 years (range, 17 to 23) and an average follow-up of 37 months (range, 24 to 60). The average Rowe score was 92 (range, 30 to 100). The average single assessment numeric evaluation patient rating was 95.5% (range, 50% to 100%). The average Short Form-36 score (physical function) for the stable shoulders was 99 (range, 95 to 100). Forty-three shoulders remained stable (88%). There were six failures (12%). Factors associated with failure included a history of bilateral shoulder instability, a 2+ sulcus sign, and poor capsulolabral tissue at the time of repair. All patients with stable shoulders returned to their preinjury levels of athletic activity. With follow-up of 5 years, we have observed significantly better results compared with nonoperative treatment in young, active adults at the United States Military Academy.

Arthroscopic shoulder stabilization with suture anchors: technique, technology, and pitfalls

Arthroscopic treatment of anterior shoulder instability has evolved significantly during the past decade. Currently, most techniques include the use of suture and suture anchors. A successful outcome is highly dependent on accurate patient selection. Preoperative evaluation, examination with the patient under anesthesia, and defining the pathoanatomy by a thorough arthroscopic examination determine the most effective treatment strategy. Technical skills include the surgeon's ability to accomplish anchor placement, suture passage, and arthroscopic knot tying. Various instruments and techniques are available to facilitate arthroscopic reconstruction. In properly selected patients and with good surgical technique, outcomes should approximate or exceed traditional open stabilization techniques.

Anatomy, pathophysiology, and biomechanics of shoulder instability

Instability in the athlete presents a unique challenge to the orthopaedic surgeon. A spectrum of both static and dynamic pathophysiology, as well as gross and microscopic histopathology, contribute to this complex clinical continuum. Biomechanical studies of the shoulder and ligament cutting studies in recent years have generated a more precise understanding of the individual contributions of the various ligaments and capsular regions to shoulder instability. An understanding of the underlying pathology and accurate assessment of degree and direction of the instability by clinical examination and history are essential to developing appropriate treatment algorithms.

HAGL lesion occurring after successful arthroscopic Bankart repair

Recurrent traumatic anterior shoulder instability following surgical repair may be associated with implant failure and an array of capsulolabral pathology including separation of the labrum (Bankart lesion), humeral avulsion of the glenohumeral ligaments (HAGL lesion), and capsular rupture. We detail a previously unreported case of a HAGL lesion occurring in a shoulder with an intact arthrosopic Bankart repair following an additional traumatic event. Anatomic repair of this subsequent injury resulted in an excellent outcome. The patient returned to his high-demand ski racing activities without any shoulder limitation.

Arthroscopic treatment of bidirectional glenohumeral instability: two- to five-year follow-up

This investigation presents the results of arthroscopic repair of bidirectional (inferior with either an anterior or a posterior component) glenohumeral instability in 54 patients with 2-year minimum follow-up. The study group consisted of 43 males and 11 females. The average age at the time of operation was 32 years (range, 15-55 years); the average interval from operation to final evaluation was 34 months (range, 26-63 months). The American Shoulder and Elbow Surgeons' Shoulder Index and the Constant, Rowe, and University of California at Los Angeles scores were recorded preoperatively and at final evaluation. Preoperatively, no patients rated good to excellent overall (according to the Rowe Scale), whereas at final follow-up 91% (49 of 54 patients) rated good to excellent. The American Shoulder and Elbow Surgeons' Shoulder Index improved to 94 from 45.5 (P =.001). The absolute Constant score improved to 92 from 57 (P =.001). The Rowe score improved to 92 from 20.3 (P =.001). The University of California at Los Angeles total score improved to 32.7 from 18.6 (P =.001). Average passive external rotation at 90 degrees of abduction measured 89.5 degrees. Forty patients returned to sports, but 10 (25%) of these patients participated at a lower level. For each of 4 patients, the index operation was considered a failure because of persistent instability; 1 patient underwent a second operative procedure. Thermal capsulorraphy (with a Holmium laser) of the glenohumeral ligaments was used to supplement suture repair, but in no shoulder was thermal capsulorraphy used as the only treatment. The etiology of bidirectional glenohumeral instability is complex, and operative correction of multiple intraarticular lesions was necessary.

Anatomical composition of the anterior shoulder joint capsule. A cadaver study on 12 glenohumeral joints

Twelve right cadaver shoulder joints were investigated after alcohol-formalin-glycerol fixation. The tendons of the "rotator cuff" were separated from the joint capsule. The capsulo-ligamentous structures: Lig. coracohumerale, Lig. coracoglenoidale and Ligg. glenohumeralia were dissected. In addition to the Ligg. glenohumerale superius, medium et inferius, an "unknown glenohumeral ligament" coursed in the midline of the superficial layer of the anterior shoulder joint capsule. It arose from the axillary part of the Lig. glenohumerale inferius and the insertion tendon of the Caput longum m. tricipitis brachii, coursed upwards laterally and fused with the Lig. glenohumerale medium. Between the Ligg. glenohumerale medium et inferius it was connected with the shoulder joint capsule by loose connective tissue. Craniolaterally it melted into the superior portion of the M. subscapularis and inserted together with its tendon to the Tuberculum minus of the Humerus. The ascending fibres of the "unknown glenohumeral ligament" and the oblique, descending fibres of the Ligg. glenohumeralia medium et inferius crossed twice and formed X-shape connections between the ligaments. In external rotation and abduction or anteversion the course of fibres of the "unknown glenohumeral ligament" was spiral. According to the shape and anatomical position of the "unknown glenohumeral ligament" we propose to name it "Lig. glenohumerale spirale".

Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs: significance of the inverted-pear glenoid and the humeral engaging Hill-Sachs lesion

PURPOSE

Our goal was to analyze the results of 194 consecutive arthroscopic Bankart repairs (performed by 2 surgeons with an identical suture anchor technique) in order to identify specific factors related to recurrence of instability.

TYPE OF STUDY

Case series.

MATERIALS AND METHODS

We analyzed 194 consecutive arthroscopic Bankart repairs by suture anchor technique performed for traumatic anterior-inferior instability. The average follow-up was 27 months (range, 14 to 79 months). There were 101 contact athletes (96 South African rugby players and 5 American football players). We identified significant bone defects on either the humerus or the glenoid as (1) "inverted-pear" glenoid, in which the normally pear-shaped glenoid had lost enough anterior-inferior bone to assume the shape of an inverted pear; or (2) "engaging" Hill-Sachs lesion of the humerus, in which the orientation of the Hill-Sachs lesion was such that it engaged the anterior glenoid with the shoulder in abduction and external rotation.

RESULTS

There were 21 recurrent dislocations and subluxations (14 dislocations, 7 subluxations). Of those 21 shoulders with recurrent instability, 14 had significant bone defects (3 engaging Hill-Sachs and 11 inverted-pear Bankart lesions). For the group of patients without significant bone defects (173 shoulders), there were 7 recurrences (4% recurrence rate). For the group with significant bone defects (21 patients), there were 14 recurrences (67% recurrence rate). For contact athletes without significant bone defects, there was a 6.5% recurrence rate, whereas for contact athletes with significant bone defects, there was an 89% recurrence rate.

CONCLUSIONS

(1) Arthroscopic Bankart repairs give results equal to open Bankart repairs if there are no significant structural bone deficits (engaging Hill-Sachs or inverted-pear Bankart lesions). (2) Patients with significant bone deficits as defined in this study are not candidates for arthroscopic Bankart repair. (3) Contact athletes without structural bone deficits may be treated by arthroscopic Bankart repair. However, contact athletes with bone deficiency require open surgery aimed at their specific anatomic deficiencies. (4) For patients with significant glenoid bone loss, the surgeon should consider reconstruction by means of the Latarjet procedure, using a large coracoid bone graft.

MR and MR arthrography to identify degenerative and posttraumatic diseases in the shoulder joint

MR imaging provides a comprehensive evaluation of a wide spectrum of both intraarticular and extraarticular pathology of the shoulder. MR imaging enables the detection or exclusion of degenerative and posttraumatic diseases of the shoulder with a reasonable accuracy. MR arthrography is useful in the visualization of subtle anatomic details and further improves the differentiation. In this article, findings of MR imaging and MR arthrography of degenerative and posttraumatic shoulder diseases (impingement syndrome, rotator cuff tears, and glenohumeral instability) has been reviewed.

Arthroscopic treatment of anterior-inferior glenohumeral instability. Two to five-year follow-up

BACKGROUND

Previous studies on arthroscopic treatment of anterior-inferior glenohumeral instability have focused on the repair of lesions of the anterior-inferior aspect of the labrum (Bankart lesions) and have demonstrated failure rates of as high as 50 percent. The current investigation supports the concept that anterior-inferior instability is associated with multiple lesions and that success rates can be increased by treating all of the lesions at the time of the operation. We present the results of arthroscopic treatment of anterior-inferior gleno-humeral instability after a minimum duration of followup of two years.

METHODS

The study group consisted of fifty-three patients who had a mean age of thirty-two years (range, fifteen to fifty-eight years) at the time of the operation. There were forty-four male and nine female patients. The mean interval from the time of the operation to the final follow-up evaluation was thirty-three months (range, twenty-six to sixty-three months). The scores on the American Shoulder and Elbow Surgeons (ASES) Shoulder Index and the rating systems of Constant and Murley, Rowe et al., and the University of California at Los Angeles (UCLA) were recorded preoperatively and at the time of the final follow-up.

RESULTS

Preoperatively, none of the patients had an overall rating of good or excellent according to the system of Rowe et al.; however, 92 percent (forty-nine) of the fifty-three patients had a rating of good or excellent at the time of the final follow-up. The mean score improved from 45.5 points to 91.7 points on the ASES Shoulder Index, from 56.4 points to 91.8 points with the system of Constant and Murley, from 11.3 points to 91.9 points with the system of Rowe et al., and from 17.6 points to 32.0 points according to the UCLA Shoulder Score (p = 0.001 for all comparisons). The mean passive external rotation with the shoulder in 90 degrees of abduction measured 88.2 degrees. Thirty-four of thirty-eight patients returned to their desired level of sports activity following the operation. Four patients who had persistent instability were considered to have had a failure of the index operation, and one of them had a second operative procedure.

CONCLUSIONS

The results of the present study suggest that our technique of arthroscopic treatment of anterior-inferior glenohumeral instability is better than previous arthroscopic techniques and is equivalent to open repair. We believe that the improved rate of success demonstrated in the present study was the result of repair not only of the anterior-inferior (Bankart) lesion but also (where necessary) of inferior and superior labral tears. Additionally, soft-tissue tension within the capsule and ligaments was corrected with use of a suture technique but was supplemented by laser thermal capsulorrhaphy in forty-eight of the fifty-three shoulders. Rotator interval repair was considered a critical factor in fourteen of the fifty-three shoulders.

Arthroscopic labrum refixation for post-traumatic anterior shoulder instability: suture anchor versus transglenoid fixation technique

SUMMARY

The aim of this retrospective study was to compare recurrence rates following transglenoid labrum refixation or fixation using the suture anchor (FASTak, Arthrex, Naples, FL) technique. Additionally, parameters that apparently influence the rate of redislocation were investigated. There were 163 patients with post-traumatic anterior shoulder instability treated with an arthroscopic labrum refixation; 108 patients (66.3%) were stabilized with the transglenoid suture technique (group I) and 55 patients (33. 7%) with the suture anchor (FASTak) technique (group II). The average follow-up was 4.5 years (range, 2.0 to 7.9 years) in group I and 3.2 years (range, 2.0 to 5.0 years) in group II. The Rowe score increased from a preoperative average of 35.0 points in group I and 35.4 points in group II to a postoperative average of 68.3 points in group I and 84.6 points in group II (P <.01). There was recurrence in 35 patients (32.4%) in group I and 9 patients (16.4%) in group II (P <.05). All incidents of redislocation occurred during the first 21 postoperative months; 58.4% of the patients (n = 63) in group I and 16.4% of the patients in group II (n = 9) had to reduce their sporting activity (P <.001). Independent of the type of surgery, there was a significant correlation of the postoperative rate of redislocation and age (P <.001), number of preoperative dislocations (P <.01), and degree of labrum lesion (P <.001). No correlation with the rate of redislocation was shown for gender, handedness, dislocation-operation interval, degree of Hill-Sachs lesion, or number of transglenoid sutures or anchors. Concerning post-traumatic anterior shoulder instability, the arthroscopic labrum reconstruction with the suture anchor (FASTak) technique was superior to the transglenoid technique but has not yet achieved the level of success obtained by open surgery. With fewer than 5 preoperative redislocations after a first traumatic shoulder dislocation, the arthroscopic treatment is recommended. In cases of more frequent preoperative dislocations, open surgery in combination with a capsular shift should be performed.

Imaging techniques for the evaluation of glenohumeral instability

The ability to image lesions associated with glenohumeral instability has evolved significantly over the past 2 decades. In the past, several imaging techniques ranging from conventional radiography to computerized axial arthrography and, most recently, to magnetic resonance imaging have been used to depict various labral abnormalities. In most instances, conventional radiography remains the initial imaging study for evaluating the patient with persistent shoulder pain and instability. Recently, however, magnetic resonance arthrography has been firmly established as the imaging modality of choice for demonstrating specific soft tissue abnormalities associated with glenohumeral instability. This article will review the role of various imaging modalities including conventional radiography, conventional arthrography, computerized axial arthrography, magnetic resonance imaging, and magnetic resonance arthrography. Emphasis will be placed on the role of magnetic resonance arthrography as it pertains to the lesions associated with glenohumeral instability. A thorough discussion of the appearance of normal anatomic structures, anatomic variations that mimic abnormality, and the various lesions associated with glenohumeral instability will be provided.

Arthroscopic versus open Bankart repair for traumatic anterior shoulder instability

After more than 15 years of experience, arthroscopic shoulder stabilization is becoming less controversial. Historically, recurrence rates following arthroscopic stabilization have been higher than with open stabilization. Although a negligible advantage may exist in terms of expedited postoperative rehabilitation and improved postoperative recovery of motion, critics suggest that its use in contact athletes be limited. The indications for arthroscopic stabilization are expanding, in part, because of improved understanding of the pathophysiology of shoulder instability. Understanding the mechanism of recurrent instability following arthroscopic stabilization offers clues to how physicians can prevent unsatisfactory results in the future. With newer instrumentation and the ability to thermally treat capsular tissue, coexisting pathology, such as capsular plastic deformation, rotator interval lesions, and unrecognized intra-articular pathology, can now be addressed arthroscopically. The judicious use of these techniques is warranted until long-term study results become available. Ideal patients for arthroscopic Bankart repair have a discrete Bankart lesion; a robust, well-developed IGHL; no significant capsular laxity or intraligamentous injury; and an absence of concomitant intra-articular pathology. Additional findings on MR imaging or CT evidence of a discrete labral lesion and pure unidirectional anterior instability during EUA are also good prognostic indicators for arthroscopic Bankart repair. Arthroscopic criteria that render patients less appropriate for an arthroscopic repair include capsular injury, capsular laxity, a bony Bankart lesion, glenohumeral arthritis, and a rotator cuff tear. The authors' believe that either absent or patulous, poorly developed glenohumeral ligaments represent a poor prognostic indicator for a successful outcome following standard arthroscopic Bankart repair. Individuals with poor-quality tissue are more predictably managed using open capsulorrhaphy. Patients with pathologic ligamentous laxity in the absence of a Bankart lesion or any apparent intraligamentous injury to the IGHL are also good candidates for treatment with an open capsulorrhaphy. Findings determined from a thorough physical examination, EUA, and the pathology appreciated during diagnostic arthroscopy help to appropriately choose the surgical procedure that effectively addresses pathology in patients who present with recurrent traumatic anterior instability. Patient preferences and surgical experience are important determinants of procedure selection, and current arthroscopic techniques lack the versatility to uniformly address the entire spectrum of pathology that may be associated with traumatic anterior shoulder instability. Surgeons should always be prepared to convert to an open-stabilization technique if the arthroscopic technique is deficient in addressing all pathology identified at the time of surgery.

Selective capsular shift technique for anterior and anterior-inferior glenohumeral instability

Anterior and anterior-inferior glenohumeral instability is often successfully treated with nonoperative measures, especially in atraumatic instability. In the case of traumatic instability, especially when the labrum is detached from the anteroinferior glenoid rim, surgery is often necessary to stabilize the shoulder and restore function. An anatomic repair that addresses any capsular or labral defect is essential for a successful outcome, and the selective capsular shift technique offers the flexibility necessary to correct these deformities. Several equally important steps must be followed when treating anterior and anterior-inferior glenohumeral instability. These include the correct diagnosis and indications for surgery; a technically successful surgical procedure; and diligent, physician-directed, closely monitored rehabilitation.

Arthroscopic shoulder instability surgery. Complications

Complications associated with arthroscopic shoulder stabilization are relatively common. Excluding recurrence, complications are rarely disabling. Current statistics undoubtedly underestimate the true incidence of complications. Many complications, including neurovascular injuries and articular damage, are preventable and can be minimized through familiarity with anatomy, proper surgical technique and instrumentation, and clinical experience. Nevertheless, despite these efforts, a few complications, including recurrent instability, persist. Despite careful patient selection and attention to labral pathology and capsular laxity, arthroscopic repairs continue to have success rates lower than those achieved through open means. While cautiously proceeding toward a more complete understanding of the instability continuum, surgeons must maintain a high index of suspicion for new techniques that purport to "solve" the problem of arthroscopic shoulder stabilization, lest the history of enthusiastic but ultimately unsubstantiated claims is repeated. Outcomes must withstand the rigors of scientific scrutiny and the test of time. Without this cautious vigilance, the appeal of today's solutions becomes the fodder of tomorrow's articles about the complications of arthroscopic shoulder stabilization.

Magnetic resonance arthrography: current status

Magnetic resonance imaging (MRI) is frequently considered the best method of diagnosis in musculoskeletal disorders. Intraarticular fluid improves joint assessment by helping to delineate intraarticular structures, separating otherwise closely-apposed structures, and filling potential spaces which lie within or communicate with the joint. Initially, it was anticipated that plain MRI would replace arthrography. The message from our surgical colleagues is that this ideal has not yet been achieved. Greater precision should reduce the need for more invasive techniques, such as diagnostic arthroscopy which is why direct and indirect MR arthrography are being employed. This article reviews the current status of MR arthrography as an evolving technique in the imaging of joint disorders.

Arthroscopic repair of full-thickness tears of the rotator cuff

We present the results of arthroscopic repair of full-thickness tears of the rotator cuff in seventy-three patients (thirty-nine men and thirty-four women). The average age of the patients at the time of the operation was 60.7 years (range, thirty-one to eighty-two years). All of the patients were followed for at least two years (average, thirty months; range, twenty-four to forty months). The shoulders were evaluated with the rating scale of the University of California at Los Angeles, the shoulder index of the American Shoulder and Elbow Surgeons, and the functional rating scale of Constant and Murley. In addition, the patients completed the Short-Form 36 Health Survey (SF-36) preoperatively and at the yearly follow-up evaluations. Eleven tears were small (less than one centimeter in length), forty-five were medium (one to three centimeters), eleven were large (more than three to five centimeters), and six were massive (more than five centimeters). The average length of the tear was twelve millimeters, and the average width was twenty-seven millimeters. Sixty-nine tendons were repaired anatomically, and four were repaired an average of three millimeters (range, two to eight millimeters) medial to the anatomical insertion of the tendon. An average of 2.3 (range, one to four) suture anchors were used in the repair. Sixty-three glenohumeral joints were normal, and ten had an intra-articular lesion. Seven patients had a concomitant resection of the acromioclavicular joint. The average duration of the operation was fifty-six minutes (range, thirty-five to ninety minutes). The active and passive ranges of motion improved significantly after the procedure (p = 0.0001). The strength of resisted elevation improved from 7.5 to 14.0 pounds (3.4 to 6.3 kilograms) (p = 0.0001). The average total score according to the rating scale of the University of California at Los Angeles improved from 12.4 to 31.1 points; the average total score according to the shoulder index of the American Shoulder and Elbow Surgeons, from 30.7 to 87.6 points; and the average absolute score according to the rating system of Constant and Murley, from 41.7 to 83.6 points (p = 0.0001 for all comparisons). The average score for the pain component of the rating scale of the University of California at Los Angeles improved from 2.4 to 8.6 points; fifty-seven (78 per cent) of the seventy-three patients rated the relief of pain as good or excellent on the visual-analog scale. The average score for satisfaction improved from 0.4 to 4.6 points; sixty-six patients (90 per cent) rated their satisfaction as good or excellent at the time of the most recent examination. None of the shoulders were rated as good or excellent before the operation, whereas sixty-one (84 per cent) were so rated at the most recent follow-up evaluation after the index procedure. In addition, significant improvements (p = 0.0015) were noted in the scales and summary measures of the SF-36. Arthroscopic repair of full-thickness tears of the rotator cuff produced satisfactory results with regard to traditional orthopaedic criteria as well as with regard to patient-assessed criteria such as satisfaction, pain relief, and general health. The arthroscopic method offers several advantages, including smaller incisions, access to the glenohumeral joint for the inspection and treatment of intra-articular lesions, no need for detachment of the deltoid, and less soft-tissue dissection. However, these advantages must be considered against the technical difficulty of the method, which limits its application to surgeons who are skilled in both open and arthroscopic procedures on the shoulder.

Combined Bankart and HAGL lesion associated with anterior shoulder instability

Traumatic anterior shoulder instability has been shown to be associated with a spectrum of capsulolabral pathology, including separation of the labrum (Bankart lesion), capsular rupture, and humeral avulsion of the glenohumeral ligaments (HAGL lesion). We describe a case of combined Bankart and HAGL lesions, a condition that has not been described before. Careful anatomic repair of both components of this bipolar capsular injury resulted in an excellent outcome.

A practical approach to imaging of the shoulder with emphasis on MR imaging

Our understanding of shoulder disorders has changed considerably as a result of improved diagnostic tools, such as arthroscopy and multiplanar imaging modalities. The diagnosis of the cause of shoulder pain can be difficult because a spectrum of disorders, including cervical spine disease, acromioclavicular arthritis, and shoulder instability. Impingement and denervation syndromes can present with similar clinical findings. Accurate depiction of anatomic abnormalities is important for treatment planning. The purpose of this article is to report on the application of available imaging modalities, with emphasis on MR imaging. A strategy for the appropriate use of these studies and their variations of technique is also provided.

Pathologic changes associated with shoulder dislocations. Arthroscopic and physical examination findings in first-time, traumatic anterior dislocations

This prospective observational study was performed on young patients, less than 24 years old, with first-time, traumatic anterior shoulder dislocations. These patients were offered either arthroscopic or nonoperative treatment. Fifty-three patients chose nonoperative treatment. Sixty-three patients elected to have arthroscopic procedures. The average patient age was 19.6 years. There were 59 men and 4 women. All procedures were performed within 10 days of dislocation. All 63 patients had hemarthrosis. Sixty-one of 63 (97%) patients treated surgically had complete detachment of the capsuloligamentous complex from the glenoid rim and neck (Perthes-Bankart lesion), with no gross evidence of intracapsular injury. Of the other two patients, one had an avulsion of the inferior glenohumeral ligament from the neck of the humerus, and one had an interstitial capsular tear adjacent to the intact glenoid labrum. Fifty-seven patients had Hill-Sachs lesions; none were large. There were six superior labral anterior posterior lesions, two with detachment of the biceps tendon. There were no rotator cuff tears. Of the 53 nonoperatively treated patients, 48 (90%) have developed recurrent instability. In this population, the capsulolabral avulsion appeared to be the primary gross pathologic lesion after a first-time dislocation. These findings, associated with the 90% nonoperative recurrence rate, suggest a strong association between recurrent instability and the Perthes-Bankart lesion in this population.

Arthroscopic reconstruction of traumatic anterior instability of the shoulder: the Caspari technique

In a prospective study, all patients with recurrent traumatic anterior instability of the shoulder were treated by an arthroscopic transglenoid suture reconstruction; 163 consecutive patients were treated during the 3-year period of the study. The average number of dislocations per patient was 11, average age 27 years, and the average preoperative Bankart score 15. All patients underwent reconstruction using the Caspari technique of arthroscopic suture reconstruction. Of the 163 patients, 161 were re-evaluated 36 to 72 months postoperatively. Overall, 147 (91%) of the patients rated as satisfactory and 14 (9%) rated as unsatisfactory. The average postoperative Bankart score for all patients was 89. Twenty of 27 patients (76%) younger than age 18 achieved a satisfactory result. Forty-nine of 54 college-age patients achieved a satisfactory result. In patients older than 22 years, 97.5% (78 of 80) achieved a satisfactory result. In this extensive study, it would appear that the success of this arthroscopic technique is age-related, with younger patients having a less successful result than older patients. Arthroscopic reconstruction with this technique provides results equal to those of the open procedure for patients age 22 years and older and would provide a success rate of 90% in patients age 18 to 22. However, it is effective only 74% of the time in patients younger than 18 and is not indicated for patients in this age range.

Humeral and glenoid detachment of the anterior inferior glenohumeral ligament: a cause of anterior shoulder instability

Recurrent anterior unidirectional shoulder instability is most commonly associated with an avulsion of the glenoid attachment of the labroligamentous complex (Bankart lesion). However, additional capsular injury is often considered necessary to allow anterior dislocation. Five patients undergoing surgical stabilization for recurrent anterior instability were noted to have not only a classic Bankart lesion but also a complete disruption of the lateral capsule from the humeral neck. Repair of this "floating" anterior inferior glenohumeral ligament was accomplished by reattachment of the medial and lateral capsular disruptions and has led to excellent postoperative function in these patients. None of the patients has had instability after an average follow-up of 26 months. Identification and repair of this unusual anatomic lesion is important and if missed may have a significant negative effect on postoperative stability.

The BHAGL lesion: a new variant of anterior shoulder instability

This article describes a new lesion associated with anterior instability of the shoulder. The bony humeral avulsion of the glenohumeral ligaments (BHAGL) is a rare lesion that may occur after anterior dislocation of the shoulder. There is a bone fragment noted on radiographs of the shoulder that may appear similar to a bony glenoid avulsion. Computed tomography typically will show that the bone is attached to the glenohumeral ligaments and does not originate from the glenoid. Arthroscopy may or may not show the lesion. This variant of anterior shoulder instability may present with impingement or instability symptoms. If symptoms fail to respond to conservative management, treatment through open excision of the bony fragment and reattachment of the glenohumeral ligaments to their origin on the anterior aspect of the humerus is indicated.