29 Distal Tibia Allograft for Failed Latarjet

10.1055/b-0039-167678

29 Distal Tibia Allograft for Failed Latarjet

Matthew T. Provencher, Anthony Sanchez, Colin P. Murphy, Liam A. Peebles, and George Sanchez

Abstract

Recurrent shoulder instability can be a frustrating condition for both patients and surgeons alike. Following a failed Latarjet procedure in the setting of significant glenoid bone loss, bony augmentation with an osteochondral allograft is indicated, and our preferred choice of allograft for these patients is the lateral one-third of a fresh distal tibia allograft (DTA). There are several advantages of the DTA, including its accessibility, dense bone quality, and congruity with the native glenoid. In this chapter, we describe the indications and contraindications of this procedure, its associated risks and benefits, and the authors’ preferred surgical technique and postoperative management.

29.1 Goals of Procedure

This procedure allows for the anatomical and biomechanical restoration of the shoulder in the setting of substantial anterior glenoid bone loss, avoiding the use of autograft. ¹ ^– ³ The goals are to prevent further instability and degenerative changes while restoring normal functionality to the glenohumeral joint. This technique is performed using the lateral one-third of a fresh DTA. ³

29.2 Advantages

Since this is an allograft technique, no autograft is required, and donor site morbidity is therefore avoided. This procedure allows for the treatment of significant glenoid bony defects, especially in the setting of a failed Latarjet revision ( Fig. 29.1a). The distal tibial surface has a similar curvature to that of the native glenoid and an excellent congruency with the humeral head can be achieved using unmatched grafts. The distal tibia allograft (DTA) is also more readily available than glenoid allografts due to the risk of infection while harvesting the more centrally located glenoid. The dense bony quality of the DTA provides a stronger fixation for the screws in the construct. This technique is performed using the modified deltopectoral approach. Furthermore, this technique can be performed to address anterior defects on the glenoid, and has been shown to restore the anatomy and biomechanics of the glenoid with a cartilaginous surface. ³

**Fig. 29.1** **(a)** Postoperative 2D CT of failed Latarjet. **(b)** Postoperative 3D CT of failed Latarjet.

29.3 Indications

DTA is indicated for patients with large anterior or posterior glenoid bony defects. This technique can be used as a primary intervention or as a revision treatment option in cases with a failed Latarjet procedure ( Fig. 29.1b). ⁴

29.4 Contraindications

Global glenoid pathology is a contraindication to this procedure, as the DTA cannot augment the entire glenoid. Small glenoid defects are a relative contraindication for this procedure; in these cases, a Bankart repair is more suitable.

29.5 Preoperative Preparation/Positioning

We recommend the use of preoperative ultrasound-guided interscalene block for regional anesthesia. The patient is then transported to the operating room, placed in a supine position, and general anesthesia is induced. Following induction, the patient is placed in the beach-chair position with all bony prominences appropriately well padded and with a bump placed behind the medial border of the scapula. The knees are slightly flexed using a foam pad. The head must be well secured. A thorough preoperative physical examination under anesthesia is performed on the shoulder to confirm the position and degree of glenohumeral instability. The shoulder is then prepared and draped in the usual sterile fashion. Using a surgical pen, all relevant bony prominences of the shoulder are marked.

29.6 Operative Technique

29.6.1 Approach

Using a scalpel, an incision is performed starting at the tip of the coracoid process and extending inferiorly along the axillary fold for approximately 7 cm, creating a modified deltopectoral incision that is slightly more medial than the standard approach ( Fig. 29.2 ). The clavipectoral fascia is identified and incised following the skin incision. The cephalic vein is identified, retracted, and protected. Gelpi or Weitlaner retractors are used to expose the fascia overlying the conjoined tendon, which is incised, and the lateral aspect of the conjoined tendon is retracted medially. The deltoid is retracted laterally using a Fukuda retractor. The subscapularis insertion on the lesser tuberosity is then identified. In primary cases, a subscapularis split can be sharply performed in line with its fibers with ease, at the junction of the superior and middle thirds. However, for revision cases, we recognize that the subscapularis tissue may not allow a split and a subscapularis takedown may be the best option for joint access ( Fig. 29.3 ). The subscapularis is tagged with a no. 2 Fiberwire suture (Arthrex, Naples, FL) for easier identification and repair later on in the technique. The underlying capsule is then released from the posterior aspect of the subscapularis tendon using Metzenbaum scissors, and a T capsulotomy is performed. The remaining capsule is sharply elevated off the glenoid neck medially in a subperiosteal fashion. Attention is then turned to the evaluation of the glenoid defect. In a revision of a prior failed Latarjet, the graft and screws must be removed, as well as any soft tissue from the anterior glenoid aspect. We use a combination of coagulator, rongeur, and high-speed burr to create a bleeding anterior bone surface for the DTA. The humeral head is also evaluated for defects and, if present, the dimension and location of the defect are identified in order to evaluate the necessity for correction.