Anatomic glenoid reconstruction with fresh osteochondral allograft for failed Latarjet

Jun 24, 2023

The Latarjet procedure has been shown to restore anterior glenohumeral stability with bone loss, although the rate of recurrence has been reported as high as 5% to 19%.

There are numerous potential issues that affect a Latarjet procedure, including graft lysis, graft nonunion or malunion, reinjury, early osteoarthritis and neurovascular issues. In addition, the nonanatomic nature of the Latarjet provides a challenge for surgeons to manage the failed procedure.

One potential graft option in the revision setting of a failed Latarjet is the distal tibial allograft (DTA). The DTA has a nearly similar radius of curvature as the native glenoid and provides excellent fixation with a large, dense bone block with an articular chondral surface. These features make it an ideal option in cases with large amounts of glenoid bone loss or after a failed prior bone block procedure.

This article aims to provide some helpful pearls and tips for performing a DTA in the setting of revision Latarjet.

The patient is placed in the beach chair position with the head elevated at approximately 45°. An exam under anesthesia is carried out to confirm the diagnosis and to determine the degree and direction of shoulder laxity. Following this, a standard deltopectoral approach is used to gain access to the anterior glenoid. The subscapularis (SSc) tendon is then exposed by releasing adhesions superiorly and inferiorly with Metzenbaum scissors.

A SSc split is made using a 15-blade in line with the fibers of the SSc at approximately the 60% (superior)/40% (inferior) split of the SSc tendon. However, in the revision situation, an SSc split may be difficult to perform, and the surgeon may convert to an SSc tenotomy at the superior half of the SSc to have adequate exposure. An L-shaped capsulotomy is then performed using a 15-blade with the apex of the "L" located superiomedially and tagged with a #2 nonabsorbable suture. The anterior aspect of the glenohumeral joint and glenoid are fully exposed with the combination of a Fukuda retractor and a small anterior glenoid retractor. The axillary nerve is palpated and protected inferiorly.

Surgical tip: The SSc split should be made medially to the level of the musculotendinous junction. Over-medialization of the split should be avoided because it increases the risk of iatrogenic nerve injury. A stay suture is placed in the superomedial corner of the capsule to help with capsular retraction and mobilization (Figure 1).

Following the Latarjet procedure, there are changes to the neurovascular anatomy of the shoulder and coracoid that surgeons must consider in the revision setting. Neurovascular complications have been reported in up to 2% of cases. A previous study by Christopher M. LaPrade, MD, and colleagues described a surgical safe zone medial to the glenoid during revision procedures for a failed Latarjet. This minimum safe zone is described as 19.8 mm medial from the glenoid to the axillary nerve, 23.6 mm to the posterior cord, 24.4 mm for the musculocutaneous nerve without neurolysis and 20.2 mm for the musculocutaneous nerve with neurolysis.

Any prior bone block or Latarjet is generally removed carefully with blunt dissection and/or Metzenbaum scissors. The conjoint tendon can be reattached to the glenoid through the SSc split with an anchor or it can just be released. It is generally scarred in at this point. If it is loose and mobile, it can be reattached to the glenoid, but generally we leave this free. In addition, any hardware is removed, so it is important to have good hardware or broken screw removal kits, depending on what the hardware looks like, as there have been broken screws or washers, bent screws and other considerations.

A Fukuda retractor is placed into the glenohumeral joint and used to gently retract the humeral head laterally. A Cobb elevator is used to elevate the scarred capsule from the anterior glenoid. The anterior glenoid is then prepared for the DTA with a high-speed burr and flattened using a powered rasp until the cortical bleeding has been recognized (Figure 2). Next, a graft template block that is sized 7 mm or 10 mm, 5° or 15° is placed on the glenoid to check for full exposure and adequate glenoid preparation (Figure 3).

Surgical tip: The capsule should be elevated as inferiorly as possible to aid with inferior graft placement. Circumferential release of adhesions from the SSc is critical to allow tendon excursion and visualization of the anterior inferior glenoid. A powered rasp can help to provide a uniformly flat anterior glenoid surface.

On a back table, the fresh DTA graft should be cut to size based on the preoperative CT scan planning. The authors’ preferred technique is using the Distal Tibial Allograft Workstation (Arthrex). Graft preparation begins by placing the intramedullary (IM) portion of the DTA over the cutting jig post and securing it with spanning Kirschner wires (Figure 4). A parallel guide with a finger projection is placed over the graft and the guide is aimed centered on the graft and at the sulcus of the graft (Figure 5). Two K-wires are inserted through the guide and over-drilled using a 4.0-mm cannulated drill bit. The cutting blocks are used to size the graft in multiple planes as per the preoperative planning. Copious irrigation is utilized to keep the fresh allograft cool while making the cuts. A small sagittal saw can be used to bevel the anterior edges of the graft prior to fixation to better match with the glenoid.

Surgical tip: Prior to fixation, two K-wires are placed in the graft, 25° to the articular surface, to assist with graft placement. The graft undergoes pulse lavage to remove remnant bone marrow elements and reduce cross-reactivity and inflammatory response risk following transplantation. Platelet-rich plasma is used to soak the graft for enhancing graft-to-bone healing. Sizing of the graft is usually 6 mm to 12 mm of glenoid surface, 1 cm depth, 20 mm to 28 mm height (superior to inferior) and it is tailored based on preoperative CT scan, as well as the guide.

The graft is then placed on the native glenoid to assess for conformity, size match and angle relative to the articular surface using the finger guide. Once the graft and glenoid positions are acceptable, two or three K-wires are placed to provisionally secure the graft. Care should be taken to ensure there is no gapping at the glenoid articular surface (Figure 6). A 2.5-mm drill is used to create the glenoid screw holes at the pre-drilled graft hole. After that, two 3.75-mm fully threaded, non-cannulated screws, each with a Suture Washer, Titanium with #2 FiberWire and Curved Needle (Arthrex), loaded with a high tensile suture, are inserted through the graft and into the glenoid (Figure 7). Then, the graft position, motion and stability are evaluated prior to capsular closure. The SSc split is repaired with standard technique using high strength, nonabsorbable sutures.

The preoperative and postoperative radiographs for a patient who had recurrent shoulder instability after the Latarjet procedure and underwent open anatomic glenoid reconstruction using fresh DTA are shown (Figures 8 and 9).

Surgical tip: Pre-loaded suture washers are used to repair the anterior capsule and labrum to the bone graft. In addition, suture anchors may be used on the native glenoid, especially at the inferior to superior margins of the graft, to facilitate capsulolabral repair.

Patients are placed in a sling for 4 to 6 weeks. The rehabilitation protocol is divided into six phases. The first phase, which begins in weeks 1 to 2, restricts biceps activation and encourages passive range of motion (ROM) up to 120° of motion in the scapular plane and forward flexion, 30° of external rotation at 0° of abduction, and abduction to 90°. The second phase, which begins in weeks 2 to 4, introduces isometric exercises for extension, external and internal rotation, and abduction, as well as increases the passive ROM to 150° of motion in the scapular plane and forward flexion, 45° of external rotation at 0° of abduction, and abduction to 90°. Week 4 begins isometric exercises for the deltoid. The third phase, which begins in weeks 6 to 12, introduces active-assisted ROM and increases passive ROM to 160° of motion in the scapular plane and forward flexion, 45° of external rotation at 0° of abduction, and abduction to 140°. The fourth phase, which begins in weeks 12 to 16, progresses to active ROM and internal and external rotation exercises are done. The main goal of the fifth phase is to increase strength, as well as introduce cable external and internal rotation at 90°, push-ups and plyometric exercises. The final phase, which begins at or after 16 weeks, allows for the gradual return of the patient to previous activities.