27 The Guided All-Arthroscopic Latarjet Procedure Using Cortical Button Fixation

10.1055/b-0039-167676

27 The Guided All-Arthroscopic Latarjet Procedure Using Cortical Button Fixation

Pascal Boileau, Eiko Hashimoto, and David Saliken

Abstract

A coracoid bone-block transfer was first proposed by the French surgeon Michel Latarjet in 1954 as a method to treat anterior instability in the setting of glenoid bone loss or revision cases. The technique provides a triple-blocking effect by reconstructing the bone loss, reinforcing the weak inferior glenohumeral ligament by transferring the conjoint tendon closer to the joint, and lowering the inferior part of the subscapularis to create a “sling-effect.” In this chapter, we describe our arthroscopic, guided surgical approach using cortical button fixation to increase the accuracy of bone-block placement, enhance the reproducibility of the procedure, and reduce the risks of complications.

27.1 Goals of Procedure

In the setting of recurrent glenohumeral instability, the Latarjet procedure stabilizes the shoulder by providing a triple-blocking effect: reconstructing glenoid bone loss, reinforcing the weak inferior glenohumeral ligament by transferring the conjoint tendon closer to the joint, and lowering the inferior part of the subscapularis to create a “sling effect.” ¹ ^– ³ It has classically been done through an open exposure using two bicortical screws, ⁴ but an arthroscopic approach has been developed. ² ^, ⁵ ^, ⁶ Our guided surgical approach using cortical button fixation increases the accuracy of bone-block placement, enhances the reproducibility of the procedure, and reduces the risks of complications. ⁷

27.2 Advantages

There are many benefits to completing the Latarjet procedure arthroscopically in addition to decreased bleeding, less postoperative pain, better cosmesis, and earlier return to sport. Improved intra- and extra-articular visualization and use of a drilling guide allow accurate positioning of the coracoid bone graft. Using a guided drilling system also allows parallel placement of the cortical button fixation with the glenoid to obtain excellent bone graft compression ⁷ and reduces risk to the suprascapular nerve. ⁵ ^, ⁸ ^– ¹¹ Cortical button fixation is an alternative to screws allowing equivalent bone graft union while minimizing complications reported with screw fixation. ¹² The arthroscope allows effective identification of the anterior neurovascular structures reducing risk of injury. Finally, there is the ability to treat associated pathologic lesions (biceps lesions, labral tears, capsular distension, and rotator cuff disease).

27.3 Indications

Recurrent anterior shoulder instability with instability severity index score (ISIS) greater than 3; glenoid bone loss greater than 20 to 25%; and failed previous surgical stabilization (Bankart repair and/or remplissage).

27.4 Contraindications

Voluntary dislocator, painful shoulder without Bankart lesion, active infection, and surgeon inexperience.

27.5 Preoperative Preparation/Positioning

A standard history and physical examination is performed. Preoperative imaging includes X-ray (true anteroposterior in internal rotation, neutral, and external rotation, axillary, scapular Y, and Bernageau profile views) and 3D CT with particular attention to glenohumeral bone loss or associated lesions ( Fig. 27.1 ). Patients receive an ISIS to guide surgical management.

**Fig. 27.1** Case example of a patient with recurrent anterior shoulder instability and significant glenoid bone loss. **(a)** Pre-op (glenoid en face view) and **(b)** 6-month post-op X-ray and CT (axillary and sagittal views) showing complete union of the coracoid bone graft.

Our patients receive a preoperative interscalene block and general anesthesia. The patient is positioned in the lazy beach-chair position (30–40 degrees), which allows lower systemic blood pressure to reduce intraoperative bleeding while maintaining cerebral perfusion ( Fig. 27.2 ). The arm is placed on a movable support (Spider Limb Positioner, Smith & Nephew, Andover, MA) without traction. The shoulder is placed in 60 degrees of flexion (to relax the anterior deltoid) and 30 degrees of internal rotation (to increase the subcoracoid space and to relax the axillary nerve). The elbow is placed at 90 degrees of flexion (to relax the conjoint tendon). Shoulder abduction is absolutely contraindicated as it brings the neurovascular structures laterally, in front of the scapular neck, putting them at risk; this is one of the reasons why we prefer the beach-chair position instead of the lateral decubitus position. Shoulder extension is also contraindicated as it reduces the anterior subdeltoid space and puts the axillary nerve under tension.

**Fig. 27.2** Patient set up in a lazy beach-chair position (30–40 degrees) with mobile arm support.

27.6 Operative Technique

The arthroscopic Latarjet includes five major steps: (1) coracoid preparation, drilling, and osteotomy; (2) glenoid labrum preparation and anchor placement; (3) subscapularis splitting and axillary nerve protection; (4) coracoid transfer and fixation; and finally (5) Bankart repair.

We use a standard posterior portal and five anterior portals ( Fig. 27.3 ). The north-west portal is used for intra-articular work; it is located at the anterolateral corner of the acromion. Four additional anterior portals will be created on each side of the coracoid during the procedure, primarily for extra-articular work. ⁵ ^, ⁷ Relative to the coracoid, the north portal is one fingerbreadth proximal, the south portal is two fingerbreadths distal (in the axillary fold), the west portal is two fingerbreadths lateral, and the east portal (passing obliquely through the pectoralis major muscle) is three fingerbreadths medial. A 70-degree scope is used to enhance visualization of the anterior neck of the scapula and eliminates instrument crowding as it has the capacity to view around acute angles. ¹³

**Fig. 27.3** Anterior portals: the north-west portal is located at the anterolateral corner of the acromion. Relative to the coracoid, the north portal is one fingerbreadth proximal and just medial; the south portal is distal in the axillary fold; the west portal is lateral to the conjoint tendon and midway between the north-west and south portals; and the east portal (passing obliquely at 45 degrees through the pectoralis major muscle) is three fingerbreadths medial to the conjoint tendon in line with the west portal.

27.6.1 Coracoid Bone-Block Preparation, Drilling, and Osteotomy

The location of the posterior portal is crucial and is located 1 cm inferior and medial to the posterior angle of the acromion. A spinal needle is used to make sure that the scope and instruments will be flush with the glenoid surface and at the level of the equator. After a diagnostic arthroscopy, the north-west portal is created. A needle is used to ensure that instrumentation will be tangential to the anterior neck of the glenoid and perpendicular to the undersurface of the coracoid.

The scope is advanced through the rotator interval and using electrocautery and following the subscapularis tendon medially, the coracoid process is identified. The coracoacromial ligament is released from the lateral border of the acromion and the conjoint tendon is identified. The north portal is created just medial to the coracoid process with the help of a spinal needle. Using a cautery through the north portal, the pectoralis minor is released from the medial border of the coracoid. In order to limit devascularization of the coracoid bone graft, do not dissect distal to the tip of the coracoid by more than 1 cm. A motorized rasp is introduced through the north-west portal and the undersurface of the coracoid process is abraded to create a flat surface to oppose the glenoid neck ( Fig. 27.4a). ⁵

**Fig. 27.4** **(a)** The coracoid rasp through the north-west portal to flatten inferior coracoid surface. **(b)** The coracoid drill guide placed through the north portal positions a drill hole 5 mm from the tip and medial and lateral edges. **(c)** The glenoid peg button is shuttled into position through the north portal in the coracoid. **(d)** The coracoid osteotomy through the north-west portal is performed 15 to 20 mm from the tip.

The coracoid drill guide (Smith & Nephew) is introduced through the north portal to grasp the coracoid perpendicular to its surface ( Fig. 27.4b). This guide ensures that the tunnel for the cortical button is equidistant to the margins and coracoid tip by 5 mm. The drill guide must be tilted 45 degrees medially to remain perpendicular to the coracoid surface; this is confirmed by visualizing the medially tine inferior to the coracoid. A drill-tipped K-wire housed inside an outer sleeve is advanced through the guide until it exits the inferior surface of the coracoid. The K-wire is replaced with a polydioxanone (PDS) suture, which is passed through the coracoid tunnel and retrieved through the west portal. The coracoid guide and sleeve are removed. The coracoid peg button (with the four-strand white suture) is pulled into place using the PDS suture as a shuttle ( Fig. 27.4c). The blue/white Cobraid suture is retrieved through the south portal and the white sutures are retrieved through the north portal. The PDS suture is left attached to the white sutures and an alligator grasper is positioned 1 cm from its tip to be used later when passing the cortical button suture across the glenoid. It is important to protect these suture strands while performing the coracoid osteotomy. An oscillating motorized saw is introduced through the north-west portal and the coracoid is osteotomized, harvesting 15 to 20 mm of bone ( Fig. 27.4d). The north portal is closed with a clip to avoid losing water outside the shoulder.

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