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Latarjet and Coracoid Transfer in Athletes

Alexander Beletsky, BA; Ian J. Dempsey, MD, MBA; Brandon J. Manderle, MD; and Nikhil N. Verma, MD

Anterior shoulder instability includes a broad range of physical findings, ranging from seemingly benign subluxations to complete dislocation of the humeral head from the glenohumeral joint. Of those presenting with primary anterior instability, as many as 40% to more than 95% go on to develop recurrent instability depending on the targeted patient population.^1–4 Recurrent instability further destabilizes the shoulder because of weakening of critical capsuloligamentous structures.⁵ Repeated translation of the humeral head over the glenoid rim can lead to bony lesions to the glenoid, bony Bankart of bone atrition^6,7 as well as the humeral head (ie, Hill-Sachs lesion).^8,9 Surgical intervention is often turned to as a means of decreasing the risk of recurrent dislocation, preventing progression of glenoid and humeral bone loss, and maintaining appropriate quality of life.^9,10 Surgical procedures for the treatment of anterior shoulder instability include both open and arthroscopic soft-tissue procedures such as the Bankart repair. When bone involvement is present, several surgical options are available. In situations with minimal glenoid bone involvement, an open or arthroscopic Bankart repair incorporating any bone fragment may be performed. Large degrees of glenoid bone involvement lends itself to bony procedures like the Latarjet, Bristow, iliac crest bone graft, and distal tibial allograft (DTA).^11–14 Additionally, the use of an iliac crest bone graft or DTA is often reserved for revision scenarios.^9,15 Hill-Sachs lesions can also play a major role in recurrent anterior shoulder instability.¹⁶ Soft-tissue procedures like remplissage or bony procedures like bulk allograft transplant may be necessary to address humeral head bone loss.^17,18 The majority of patients with recurrent anterior instability exhibit a bony Bankart lesion or glenoid rim irregularities, but may also exhibit “bipolar bone loss” in the scenario of bony changes to both the glenoid and humeral head.^8,19,20 Although traditionally bone loss thresholds surpassing 20% have been linked to increased risk of failure with soft-tissue repair,^21,22 new literature has suggested that “subcritical” glenoid bone loss may also pose heightened risks of recurrent instability.^23–25 As a result, bony techniques are receiving increased consideration, particularly in cases of recurrent instability and even primary instability in patients with significant bone loss.^26,27

EVALUATION AND INDICATIONS

Initial Evaluation and Diagnostic Steps

Clinical assessment begins with a thorough patient history, physical examination, and appropriate imaging. During the initial history taking, one must identify the mechanism of injury (subluxation vs dislocation) with specific discussion on how the shoulder was reduced if a dislocation occurred (eg, self-reduction, on-field reduction, need for emergency department evaluation, and sedation). Other key features include the frequency of dislocation and/or subluxation events, history of hyperlaxity, and sport-specific factors (eg, collision sports, swimming, overhead athletes). Physical examination should include inspection, palpation, and the assessment of a patient’s range of motion (ROM) (ie, flexion, extension, abduction, internal rotation, external rotation), strength, and neurovascular status to exclude neurological sequelae common in shoulder dislocation (ie, axillary nerve palsy, brachial plexus palsy). Provocative testing should be used to assess for the presence of specific patterns of instability (ie, anterior, posterior, multidirectional). Anterior and posterior instability can be assessed using a combination of the sulcus sign on arm traction and the load-shift test.28 The relocation test is particularly useful in the diagnosis of anterior instability, given a positive predictive value of 98% and a specificity of 99%.²⁹ Other clinical tests, such as the hyperabduction test, Kim test, and jerk test, can assess for inferior and posterior instability.^30,31

Imaging evaluation is particularly critical in the evaluation of acute instability, in that anatomic reduction is confirmed on radiographs. Important views to obtain include true anterior-posterior (Grashey), axillary, and scapular-lateral views. These images are critical in establishing humeral head alignment and aid in the diagnosis of any related fractures. Computed tomography (CT) is the optimal imaging modality for assessment of the role of glenoid bone loss in management. The preferred methodology for optimal glenoid bone loss measurement is the use of thin-slice CT imaging with 3-dimensional (3D) reconstruction, allowing for subtraction of the humeral head to provide an en face view of the glenoid. Magnetic resonance imaging (MRI) has an important role in the evaluation of possible soft-tissue injury, including the evaluation of capsulolabral structures of the shoulder. MRI may also be used to calculate bone loss; however, correlations between modalities ranged from 0.39 to 0.64 depending on the dimension of interest.^32–34 After gathering this important information, the provider and athlete should discuss the athlete’s functional expectations as it relates to return to future play.

Bone Loss: Glenoid, Humeral Head, or Bipolar?

The importance of assessing bone loss cannot be overlooked both in the primary and recurrent anterior shoulder instability patient. The presence of specific bony defects can in some cases signal the need for urgent surgical intervention (eg, bony Bankart lesion in acute instability).³⁵ When using the aforementioned imaging techniques (eg, 3D CT) to evaluate for bone loss, it is critical to evaluate for bony changes both to the glenoid and humeral head. Bipolar bone loss has traditionally been evaluated using the concept of “engaging or nonengaging” humeral head lesions that rely on the identification of important risk factors for failure after arthroscopic Bankart repair (ie, “inverted-pear” glenoid, a Hill-Sachs lesion that engages the glenoid in abduction and external rotation).³⁶ More recently, Itoi et al used 3D CT to define the contact zone between the glenoid and humeral head as a “track.” An “on-track” is a nonengaging Hill-Sachs lesion that occurs when the medial margin of a Hill-Sachs lesion falls onto the glenoid rim so the bony support exists medially. An “off-track” or engaging lesion on the other hand occurs when the edge of the Hill-Sachs lesion is more medial than that of the glenoid track, so no bony support exists.^37,38

The methodology to determine the on-track or off-track nature of a Hill-Sachs lesion in the presence of glenoid bone loss begins with the use of 3D-CT with bone reconstruction to model the glenoid and humeral head. Glenoid bony defect size may be assessed using various methods, such glenoid length,³⁹ width-to-length ratio,²² glenoid index,⁴⁰ and the defect area.¹⁹ The method preferred at our institution involves the glenoid index, using the sagittal view on CT to superimpose a circle encapsulating the glenoid circumference (Figure 10-1). If CT of the contralateral shoulder is available, it may be used as a reference point for estimation of the total glenoid width. Otherwise, we estimate a perfect circle fit of the glenoid on the operative side and measure the total circle diameter and defect diameter. Dividing the defect diameter by the total circle diameter yields the estimated percentage of glenoid bone loss. Eighty-three percent of the total glenoid width minus the defect size is calculated.⁴¹ The medial rotator cuff attachment margin is estimated on the humeral head, and the previous measurement is used to mark the medial glenoid track edge with the presence of a glenoid defect. If the Hill-Sachs lesion extends beyond the estimated medial edge, the lesion is considered to be off-track37 (Figure 10-2).

Management Options

Nonoperative management may be favored in patients with primary instability without signs of Bankart lesions on MRI, although previous studies have demonstrated that up to 97% of athletes with anterior shoulder instability present with either a labral lesion or damage to supporting ligaments.⁴² A Sullivan brace may be used in athletes to permit completion of the season of play, although the benefit of delaying management must be weighed against the risk of redislocation and further injury. Surgical management most often applies to the athlete suffering recurrent instability with the goal of further injury prevention, maintenance of appropriate neurovascular status, and re-establishing confidence in shoulder function. Two distinct classes of surgical interventions include soft-tissue operations and bony procedures. The primary soft-tissue repair technique is the arthroscopic Bankart repair, often performed using suture anchors placed along the inferior glenoid rim.^43–45 Bony procedures include the Latarjet, Bristow, iliac crest bone graft, and DTA, each of which harvest various bony grafts and transfer them to the anterior glenoid to provide a bony block to future anterior dislocation.^{12–14,46,47} Risk factors of failure following primary arthroscopic shoulder stabilization include the following: male sex,⁴⁸ age younger than 20 years,⁴⁸ 3 or more preoperative dislocations,⁴⁸ 3 or fewer suture anchors,⁴⁹ and beach-chair positioning.^50,51 Significant glenoid or humeral head bone loss is the most well-established risk factor across the literature. Significant glenoid bone loss is classically defined as an inverted-pear glenoid configuration or more than 20% glenoid bone loss, and significant humeral head bone loss defined as an engaging off-track Hill-Sachs lesion.^8,14,37,49 Greis and colleagues showed that as bone is lost from the anterior glenoid, the contact area of the glenoid decreases significantly, thus resulting in increased contact pressure in the anteroinferior quadrant.⁵² Biomechanical studies have set the stage for re-examination of the benefit of bony procedures at lesser degrees of “subcritical” bone loss. Jeon et al demonstrated comparable outcomes between Bankart repair and the Latarjet in those with glenoid bone loss levels of 15% to 20%,⁵³ and Shaha and colleagues demonstrated the need to redefine the “critical” bone loss threshold given bone loss of more than 13.5% leading to decreased patient-reported outcome scores postoperatively.²⁴ All relevant risk factors should be balanced with an athlete’s expectations for return to sport (RTS) success and time. A recent meta-analysis suggested that patients undergoing Bankart repair have the greatest rates of return to preinjury sport levels compared to the Latarjet, respectively (91.5% vs 69.0%).⁵⁴ Accordingly, soft-tissue fixation with arthroscopic Bankart repair is the most common first line of treatment in the athlete with low to intermediate risk factors of surgical failure. When decision making is unclear, an Instability Severity Index Score can be used to better predict the risk of failure after arthroscopic Bankart repair based on age, involvement in competitive sport, and hyperlaxity, among other variables.⁵⁵

Bony Surgical Intervention for Anterior Instability: Latarjet

The Latarjet, also known as the Latarjet-Bristow procedure, has been established as a reliable treatment option for individuals with recurrent anterior shoulder instability.^56–58 In the context of recent studies suggesting increased failure rates with even “subcritical” levels of bone loss as low as 13.5%, interest in the use of the Latarjet is increasing.^24,56 The premise of this surgical technique is the transfer of the coracoid process from its natural position in the anterior shoulder to the anterior edge of the glenoid where the bony defect resides. Transfer of the coracoid in this fashion presents a possible “triple effect” of mechanisms bringing stability to the glenohumeral joint, including (a) the “sling effect,” in which the subscapularis and/or conjoint tendon increase dynamic stabilizing forces on the glenohumeral joint^58,59; (b) the “bone-block effect,” in which the transferred bony fragment provides a hard stop preventing full dislocation of the humeral head59–61; and (c) the “Bankart” effect in which repair of the capsulolabral complex or coracoacromial ligament (CA) provides additional stability to the labrum.²⁶ The Latarjet offers superior results with respect to instability event recurrence, perceived apprehension, and patient satisfaction when compared to soft-tissue repair.^57,58 Recurrent instability rates are in the single digits after Latarjet and have been reported to exceed 20% after soft-tissue repair for recurrent instability.^57,62

Indications and Contraindications for Latarjet

The 2 primary indications for Latarjet include (1) recurrent anterior instability in the context of failed primary soft-tissue fixation, and (2) primary surgical intervention for anterior instability in the context of “significant” bone loss.⁶³ Previously, absolute thresholds for significant bone loss (ie, > 20%) have been replaced with more nuanced views that even subcritical bone loss (13.5% to 20%) may predispose patients to failure after soft-tissue repair.^{8,19,24,25,56} Accordingly, providers must synthesize this structural information with known risk factors based on patient history (ie, young age, male sex, previous surgery on operative shoulder, hyperlaxity) to appropriately educate the patient to make an informed medical decision. Specific contraindications to the Latarjet procedure include (1) recurrent anterior instability associated with a massive irreparable rotator cuff tear, (2) primary traumatic dislocation in the presence of glenoid rim fracture requiring open reduction and internal fixation of the rim fracture, (3) patients suffering from uncontrolled seizure activity despite adequate medical intervention, and (4) unstable painful shoulders with high suspicion of “micro-instability,” a relatively new clinical entity defined by any pathological laxity leading to abnormal shoulder mechanisms without frank instability.^26,64,65

Athletes warrant special consideration with respect to surgical options for anterior shoulder instability. Glenohumeral instability accounts for nearly 1 in 4 shoulder injuries suffered by American collegiate athletes.⁶⁶ Specific athletic populations have demonstrated a predisposition toward recurrence of anterior shoulder instability, including collision sports such as rugby and football. Collision sport athletes (eg, rugby, football, hockey) have demonstrated recurrence rates ranging from 14.7% to 28.6% after soft-tissue stabilization when compared to contact sport athletes (eg, field hockey, soccer, basketball, wrestling), who have demonstrated recurrence rates of 0.0% and 14.7%, respectively.^67,68 Consequently, there may be value in having a lower threshold for pursuing bony procedures in collision athletes with the hope of minimizing the risk of recurrent dislocation and the need for potential revision surgery.³⁶ These benefits must be weighed against the possible disadvantages, including decreased RTS rates reported for the Latarjet when compared to Bankart repair.⁵⁴ Further study is required to more definitively identify differences in the rates and time to RTS in athletes based on competitive status (recreational vs competitive) and by sport (collision, contact, noncontact).

SURGICAL TECHNIQUE FOR LATARJET

This section details the technique used to perform a mini–open Latarjet as practiced by the senior author. Important technical variations are detailed with respect to approach, treatment of the subscapularis, optimal coracoid technique (eg, standard, articular congruity), optimal positioning on the anterior glenoid, and capsular management.

Anesthesia, Patient Positioning and Diagnostic Arthroscopy

Patients undergoing the Latarjet receive general anesthetic agents often in conjunction with regional anesthesia (commonly an interscalane block) to provide appropriate intraoperative analgesia and full muscle relaxation. Adjunctive interscalene nerve blocks demonstrated reduce postoperative pain and postoperative analgesic requirements in open-shoulder surgery patients, in addition to increasing patient satisfaction more broadly in those undergoing shoulder surgery.^69,70 The mini–open technique described in this section seeks to use a standard deltopectoral incision while limiting incision size. Once the patient is appropriately anesthetized, an exam under anesthesia is performed to confirm previous exam findings characteristic of shoulder instability. Diagnostic shoulder arthroscopy using a standard 2-portal approach is performed with the patient in a beach-chair position sitting upright at approximately 90 degrees.^71,72 Appropriate positioning of the patient aligns the medial border of the scapula with the lateral edge of the bed to allow for full scapular retraction, external rotation, and abduction. This is particularly important during the harvesting of the coracoid graft, when the arm is externally rotated and abducted for appropriate visualization. The patient is repositioned for the Latarjet by lowering the head of the bed to a 20- to 30-degree incline and placing the arm into an externally rotated and abducted position. It is important to note that the Latarjet is being performed arthroscopically with more frequency, although the literature demonstrates a significant learning curve and consequent risk of inappropriate graft placement and possible redislocation.^73–77

Deltopectoral Approach, Coracoid Exposure, and Coracoid Osteotomy

A 5 cm deltopectoral incision is made approximating the medial and inferior edge of the deltoid following Langer’s lines in line with the coracoid. Careful attention is paid to mobilize the cephalic vein laterally opening the deltopectoral interval. The subscapularis is identified. Retractors are strategically placed to avoid structural damage to adjacent neurovascular structures. The conjoint tendon is identified and tracked proximally to the coracoid tip. Retractors are then repositioned to have full visualization of the superior, inferior, medial, and lateral surfaces of the coracoid. Laterally, the CA ligament is dissected and released with a 1-cm stump, which is important for later closure. The coracohumeral ligament is also released just deep enough to reach the CA ligament because this tissue can prevent appropriate mobilization of the coracoid after osteotomy. Medially, the insertion of the pectoralis minor is identified and released off the coracoid in a subperiosteal fashion. Once mobilized appropriately, the anterior aspect of the coracoid process can be appropriately palpated to approximate the extent of the osteotomy (Figure 10-3). A Bovie cautery may be used to identify the top of the coracoid and the proposed osteotomy site. At this time the coracoclavicular ligaments should be palpated at the base of the coracoid to ensure they are not disrupted during the osteotomy. The osteotomy site is marked 2 to 3 cm proximally to the anterior coracoid edge. A coracoid retractor is placed medially. The osteotomy is performed using a 90-degree saw cutting from medial to lateral. The osteotomy is completed using an osteotome. The Bovie cautery is used to free the coracoid from any remaining medial soft tissue. Keep in mind during dissection that the musculocutaneous nerve lies approximately 5 cm distal to the coracoid.

Coracoid Graft Preparation

With the coracoid graft freed, a coracoid holder is used to prepare the graft. The inferior aspect of the graft is flattened and decorticated to aid in bony fusion. A coracoid drill guide is attached to determine appropriate spacing of the 2 drill holes. Two holes are drilled through the coracoid process from inferior to superior and marked with the Bovie cautery. The offset guide is placed in either hole to determine the appropriate offset to the articular surface. This also determines which offset guide that will be used later for fixation. The depth of the coracoid is also measured using a depth gauge. It is important to note that the standard Latarjet technique fixes the inferior coracoid surface onto the anterior glenoid (the technique described here), with the lateral edge of the graft lying in plane with glenoid articular surface. This is in contrast to the congruent arc modification, in which the medial surface is fixed onto the anterior glenoid with the inferior edge of the graft lying in place with the glenoid articular surface.⁴⁶ Neither technique has been appropriately compared with respect to RTS or outcomes in athletes. Cadaveric studies have suggested that the congruent arc technique allows the bone graft to more closely match the native glenoid curvature and gives an overall wider graft, but it also requires fixation through the thinnest portion of the glenoid which may predispose the graft to intraoperative fracture (Figure 10-4).⁷⁸

Glenoid Exposure, Subscapularis Treatment, and Coracoid Fixation

With the coracoid bone graft prepared appropriately, a horizontal split of the subscapularis in the middle of the tendon (50-yard line) in line with its fibers is preferred. The angle of the horizontal split is typically 20 degrees cephalad. This is particularly important in athletic patients hoping to preserve strength with respect to internal rotation and adduction. Other treatment strategies for the subscapularis include partial tenotomy and an L-shaped incision; however, these techniques are largely inappropriate in the athletic patient because of concern for subscapularis atrophy and reduced strength of internal rotation when compared to the horizontal split technique described.79,80 After the subscapularis is split and retracted, the capsule is identified and dissected away from the subscapularis. A horizontal incision is made sharply through the capsule to expose the anterior glenoid. A Fukuda retractor is placed to move the humeral head laterally. An anterior glenoid retractor is placed exposing the capsule. A Bovie is used to “T” open the capsule for anterior glenoid exposure. The superior and inferior leaflets of the capsule are tagged at this time for retraction and later closure.

Related posts:

Decision Making in Surgical Treatment of Athletes With First-Time vs Recurrent Shoulder Instability Open Treatment of Anterior Instability Evaluation of Shoulder Instability on the Field and in the Clinic Management of In-Season Athletes With Posterior Glenohumeral Instability Arthroscopic Anterior Shoulder Instability in the Athlete Imaging of Posterior Shoulder Instability

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