History

The diagnosis of an anterior dislocation is usually readily apparent.³ The patient typically gives a history of a specific injury in which the shoulder “popped out.” In some cases, dislocation occurs with no history of significant trauma; these patients are frequently noted to have generalized ligamentous laxity and are less likely to demonstrate a Bankart lesion.

The diagnosis of anterior subluxation is often more subtle. The chief complaint may be a sense of movement, pain, or clicking with certain activities. Pain, rather than instability, may be the predominant complaint. In throwers and other overhead athletes, “dead arm” episodes may occur during which the patient experiences a sharp pain followed by loss of control of the extremity.⁴ It should also be noted that patients who report multiple dislocations, atraumatic dislocations (in sleep), or continued instability should be evaluated for potential bone loss on the anterior glenoid.

Physical Examination

Apprehension tests are designed to induce anxiety and protective muscle contraction as the shoulder is brought into a position of instability. The anterior apprehension test is performed with the arm abducted and externally rotated. As the examiner progressively increases the degree of external rotation, the patient develops apprehension that the shoulder will slip out. This test result is uniformly positive in patients with anterior instability.

During the relocation test, the examiner’s hand is placed over the anterior shoulder of the supine patient. A posteriorly directed force is applied with the hand to prevent anterior translation of the humeral head. The shoulder is then abducted and externally rotated as it is in the apprehension test. A positive result is obtained when this anterior pressure allows increased external rotation and diminishes associated pain and apprehension. The relocation test seems to be more reliable in overhead athletes, and the result may not be positive in all cases of anterior instability.

The belly press and liftoff tests should also be performed to confirm the integrity of the subscapularis tendon in the setting of an anterior dislocation.

Imaging

Routine radiographic examination of the unstable shoulder includes an anteroposterior view (deviated 30 to 45 degrees from the sagittal plane to parallel the glenohumeral joint), a trans-scapular (Y) view, and an axillary view. In the assessment of more chronic instability, West Point and Stryker notch views are helpful in demonstrating bone lesions of the humeral head and glenoid.

Magnetic resonance imaging is not necessarily performed routinely in patients with instability because the findings are usually predictable; however, it may be helpful in preoperative planning. The accuracy of magnetic resonance imaging in determining labral disease is increased with arthrography. Because of the possibility of concomitant rotator cuff injury, magnetic resonance imaging should always be considered in older patients with instability—especially if strength and motion are slow to recover after an episode of dislocation. Lastly, if the patient has a history of multiple dislocations or unidirectional atraumatic dislocations or there is a suggestion of bony deficiency on the radiographs, a CT scan is recommended to evaluate for any bone loss on the anterior glenoid and to assist in the preoperative planning.

Indications and Contraindications

The indications for surgical treatment of recurrent anterior shoulder instability are highly subjective. They include a desire of the patient to avoid recurrent problems with instability (including the necessity of reporting to the emergency department on a frequent basis to have the shoulder reduced), problems with recurrent pain, an inability to perform certain activities because of a fear of further shoulder instability, and the desire to improve athletic performance with improved shoulder stability. Failure of a thorough trial of nonoperative treatment is also an indication for surgical treatment.

There are several relative contraindications to performing a stabilization procedure by an arthroscopic method in patients in whom an operation is deemed advisable. Although there is controversy in this area, reported indications for open stabilization over arthroscopic stabilization include participation in a contact or collision sport, bone defects of the humeral head or glenoid, humeral avulsion of the glenohumeral ligaments, rupture of the subscapularis in association with a traumatic dislocation, failed open or arthroscopic repair, and atraumatic instability.

Contraindications to the open technique include voluntary instability and concomitant psychological issues. Large defects of the humeral head (Hill-Sachs lesions) or glenoid may require supplemental bone grafting to fill the defects⁵; however, the recent trend toward increased performance of the Latarjet procedure may be an overreaction. The literature has shown consistently high levels of success with conventional open techniques of stabilization (without bone blocks) in patients with bony defects of the humeral head and/or glenoid. Owing to success with the procedure described later, in my practice the Latarjet procedure is considered only in patients who have glenoid defects involving more that 30% of the glenoid diameter or in patients with humeral head defects involving more than 25% of the head and with a depth of at least 1 centimeter. I seldom perform bone block procedures except in revision cases.

I prefer to use arthroscopic methods of stabilization in throwing athletes. If an open method is used in this group, I recommend the technique of anterior capsulolabral reconstruction described by Jobe,⁶ in which the subscapularis tendon is split rather than detached.

Anesthesia and Positioning

The procedure is performed after placement of an interscalene block. In some cases the block is supplemented with general anesthesia. The patient is positioned supine with the head of the operating table raised 15 to 30 degrees and the involved upper extremity abducted 45 degrees on an arm board. Folded sheets are placed beneath the elbow and taped to the arm board. The sheets maintain the arm in the coronal plane of the thorax and minimize extension of the shoulder.

The surgeon initially stands in the axilla area. Two assistants are used. The first assistant’s primary responsibilities are to control arm position and to keep the humeral head reduced during the capsular repair. The first assistant alternates position with the surgeon. When the surgeon is in the axilla area, the first assistant stands lateral to the arm. When the surgeon moves to the lateral aspect of the arm, the first assistant shifts to the axilla. The first assistant also holds the humeral head retractor when it is in position. The second assistant stands on the opposite side of the table and holds the medial (glenoid) retractors. The use of a mechanized arm holder can free the assistants’ hands and may facilitate exposure.