Anterior Instability: Open Latarjet Procedure

T. Bradley Edwards

Ross Doehrmann

INDICATIONS

The shoulder is the most commonly dislocated joint in the body occurring at a frequency of 23.9 per 100,000 person-years with more than 90% of instability episodes being anteroinferior.¹^,² Failure to properly manage patients with shoulder instability can have dire consequences and lead to recurrent episodes of instability and increases the likelihood of dislocation arthropathy. In the United States, an arthroscopic Bankart repair is the preferred surgical technique after traumatic anterior shoulder instability secondary to its success in restoring glenohumeral stability and relatively low complication profile compared to open procedures.³ However, recurrence rates after arthroscopic stabilization range between 10.8% and 21.1% with younger age (<22 years old), men, competitive-level sports, and collision athletes being recognized as patient-related risk factors.⁴^, ⁵^, ⁶^, ⁷^, ⁸ ^and ⁹

The presence of glenohumeral bone loss has also been shown to negatively affect outcomes after nonoperative and arthroscopic treatment of shoulder instability. In the presence of glenoid bone loss, Burkhart and Debeer reported a 67% failure rate after arthroscopic Bankart repair with 89% of contact athletes having recurrent instability. In cases involving off-track Hill-Sachs lesions, some authors advocate for the addition of a remplissage. However, this has been shown to decrease external rotation in some series and may be detrimental to overhead athletes.⁹^,¹⁰

The Latarjet procedure addresses glenoid bone loss, converts Hill-Sachs lesions to on-track and restores glenohumeral stability without limiting external rotation.¹¹ As noted by Patte, the rationale for the Latarjet procedure was described as the “triple blocking effect.” Most obvious is the increase in anteroinferior glenoid contact area by the coracoid bone block. Second, is the sling effect provided by the conjoined tendon that reinforces the inferior subscapularis and anteroinferior joint capsule with the arm in abduction and external rotation. The third mechanism of stability is afforded by repair of the capsule and anteroinferior glenohumeral ligaments to the coracoacromial ligament. Distinct advantages of the Latarjet include a less than 2% rate of recurrence, minimal loss of external rotation, no postoperative limitation of motion, and earlier return to activity with full participation allowed at 3 months postoperative.

At our institution, indications for a Latarjet procedure include select patients with recurrent anterior shoulder instability, anteroinferior glenoid bone loss, and revision instability surgery.

PREOPERATIVE PREPARATION

A detailed history is important as several patient and demographic factors have been shown to influence outcomes. In particular, the physician should inquire about the mechanism of injury, prior dislocation events, age of first dislocation, method of reduction (self-reduction or physician-assisted),
and any treatment received. Patients with recurrent dislocations with activities of daily living or during sleep may raise concern for osseous defects. Physicians should inquire about the degree and type of athletic involvement, which have also been shown to affect the outcomes.

A thorough examination of bilateral shoulders is important. Provocative exam maneuvers including the apprehension and relocation tests are performed to confirm the direction and to assess the degree of instability. The jerk test may be conducted to assess for posterior instability. Patients are examined for signs of generalized ligamentous laxity, including the sulcus sign, which may indicate multidirectional instability. Axillary nerve sensorimotor function and rotator cuff strength should be examined as injuries to both are seen after anterior shoulder dislocations especially in older individuals.¹²

Routine radiographs of patients with shoulder instability include anterior-posterior views with the arm in neutral, internal, and external rotation in addition to a glenoid profile view as described by Bernageau with a comparison to the contralateral shoulder.¹³ With these views, we are able to detect 95% of osseous lesions with 90% of glenoid rim lesions and 76% of Hill-Sachs lesions being identified in patients following recurrent anterior shoulder instability.¹⁴

TECHNIQUE

Preparation and Positioning

The night prior to the surgery, the patient is advised to shave the region of the shoulder girdle and cleanse using an antibacterial soap. Directly before the surgical procedure, an interscalene block is administered to manage postoperative discomfort. The patient is then given general anesthesia and positioned in the adjusted beach chair position with the back elevated roughly 60°. To make the coracoid more readily palpable, we place a 1-cm folded sheet beneath the scapula of the affected shoulder prior to draping (Figure 34-1). A surgical assistant is used to help stabilize and position the arm throughout the procedure.

FIGURE 34-1 A, Patient in beach chair position for the procedure. B, A 1-cm folded sheet is placed behind the operative scapula to make the coracoid process more easily palpable.

Skin Incision and Surgical Exposure

The incision is slightly more vertical than our approach used in total shoulder arthroplasty. Starting at the tip of the coracoid, a 5-cm skin incision is made extending inferiorly toward the axillary fold (Figure 34-2). If cosmesis is a concern (ie, young females), an incision as small as 3 cm may be used. Working through a small window necessitates meticulous hemostasis to maintain visualization, which is accomplished with the use of needle-tip electrocautery throughout the dissection. The deltopectoral interval is identified superiorly and medially by identifying the small triangular region devoid of muscle. The cephalic vein is identified within the triangle and taken laterally. Care should be taken as a branch of the vein often crosses the field superiorly. This vein is ligated with absorbable suture to prevent postoperative hematoma. The intermuscular interval is opened and a self-retaining retractor (cerebellar retractor) is placed between the pectoralis major and deltoid.

FIGURE 34-2 Vertical skin incision beginning at the coracoid process and extending inferior toward the axilla.

Coracoid Process Harvest and Preparation

The arm is held in abduction and external rotation, which aids in exposure. Mayo scissors are used to clear the superior aspect of the coracoid and a Hohmann is placed over top of the coracoid to expose the anterior edge of the coracoacromial ligament as well as the lateral edge of the conjoined tendon (Figure 34-3). The coracoacromial ligament is then transected leaving a 1-cm stump attached to the coracoid. The arm is adducted and internally rotated to help expose the pectoralis minor tendon medially, which is identified and released from its coracoid insertion. Exert caution when releasing the pectoralis minor to avoid disrupting the blood supply to the coracoid that enters along the medial aspect of the conjoined tendon attachment. After releasing the pectoralis minor, the flexure or “knee” of the coracoid is exposed by sliding a Cobb elevator along its inferomedial aspect. Next, the coracoid osteotomy is performed with a microsagittal saw equipped with a 90° blade (Figure 34-4). With the elevator in place to protect the neurovascular structures medially, the cut is initiated at the flexure starting along the medial aspect of the coracoid. Once the plane of the cut is established, the elevator is removed and the cut is completed in a medial to lateral direction. In larger patients, an osteotome may be needed to complete the osteotomy through the inferolateral cortex. A Lahey traction clamp is used to hold the coracoid and the arm is externally rotated to tension the coracohumeral ligament. The ligament is released from the coracoid to complete the graft harvest and the arm is returned to a neutral position.

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