28.1 Introduction

Primary glenohumeral dislocations without bone loss are most commonly treated with arthroscopic anterior labral repair. However, with recurrent dislocations and/or dislocations with significant bone loss, recurrent instability after arthroscopic repair is problematic. The Latarjet procedure is the most commonly utilized procedure for recurrent dislocation or instability with critical bone loss. The Latarjet has three mechanisms of stabilization: (1) the bony support of the coracoid increasing the glenoid surface area, (2) the conjoint tendon acting as a dynamic sling on the inferior subscapularis, and (3) the repair of the capsulolabral junction. ¹

When there are larger degrees of bone loss, the Latarjet procedure may not provide sufficient stability. The Eden–Hybinette uses an iliac crest bone graft (ICBG) to reconstitute glenoid bone loss and is an alternative to the Latarjet procedure, especially in revision cases or cases of larger bone loss.

28.2 Goals of Procedure

The goal of the Eden–Hybinette is to reconstitute glenoid bone loss using autogenous ICBG.

There is continued debate on what constitutes critical glenoid bone loss. Gerber et al defined significant glenoid bone loss when the length of the defect is greater than half of the maximum anteroposterior diameter of the glenoid fossa. ² Itoi et al concluded in a cadaveric study that a defect of greater than 21% of the superoinferior glenoid length cannot be addressed by a labral repair without bone grafting. ³ Burkhart et al reported that a defect greater than 25% of the glenoid width failed without bone grafting; in such cases, the Bankart repair alone did not yield satisfactory results. ⁴ Given the importance of evaluating glenoid defects in anterior shoulder instability, Jankauskas et al concluded that the loss of sclerotic glenoid line (LSGL) serves as a diagnostic indicator of anterior glenoid rim defects that cannot be treated by Bankart repairs. ⁵

Yamamoto et al showed that critical bone loss in bipolar lesions is often associated with glenohumeral instability. ⁶ They defined the “glenoid track” in a cadaveric study as the contact zone between the glenoid and the humeral head. He concluded that if the medial margin of a Hill–Sachs lesion is more medial than the glenoid track in bipolar lesions, standard stabilization procedures such as Bankart repairs would be unlikely to restore stability of the shoulder.

Although there is debate on what defines critical bone loss, most shoulder experts agree that a soft-tissue Bankart repair is insufficient. In most situations with critical bone loss, the Latarjet is a good surgical option; however, there are situations where the Latarjet may not be adequate. The literature reports a 5 to 6% redislocation rate after the Latarjet. ^{7 , 8} Adopting the concept of the “glenoid track,” Mook et al argued if there is a persistent “off-track” relationship, then there is a significantly higher probability of recurrent instability after the Latarjet. ⁹ This off-track relationship occurs if the Hill–Sachs lesion is medial to the track and/or if the patient has a relatively undersized coracoid process with a large glenoid defect.

When there are larger degrees of bone loss, the Latarjet procedure may not provide sufficient stability. In such situations, the Eden–Hybinette using the ICBG is an option that provides a larger amount of bone graft for stabilization.

28.3 Advantages

The Eden–Hybinette is advantageous compared to the Latarjet because it allows treatment of larger defects; however, this comes at the expense of the graft harvest site. There are advantages of healing and avoiding the risk of disease transmission when compared to distal tibia allograft.

Lunn et al reported their series on the treatment of recurrent anterior dislocation after a failed Latarjet procedure using the modified Eden–Hybinette operation. ¹⁰ In their series, 79% reported good or excellent results. Warner et al reported a case series of anatomic glenoid reconstruction using the modified Eden–Hybinette. ¹¹ In this series, all patients returned back to preinjury level of activity. This has been reported to have good to excellent results. In using autogenous graft, there is no concern for disease transmission or graft rejection. Furthermore, the use of the autogenous graft is a cost-efficient alternative to allograft (tricortical iliac crest or distal tibia).

28.4 Indications

We perform the Eden–Hybinette in the following situations: (1) glenohumeral instability with bone loss greater than 40%, (2) revision surgery after failure of Latarjet, and (3) acute, unreconstructable glenoid fracture with subluxation or frank instability.

28.5 Contraindications

Patients with active infections, uncontrolled seizures, or the inability to follow postoperative directions are contraindications to the Eden–Hybinette procedure.

28.6 Preoperative Preparation/Positioning

For preoperative planning of the Eden–Hybinette procedure, CT of the scapula with 3D reconstruction is obtained to calculate the amount and shape of glenoid bone loss. If available, computerized/virtual surgical tools for patient-specific instrumentation and planning should be used to best understand the patient’s anatomy and defect. If possible, obtaining a sterilized 3D printed model of the scapula will allow the surgeon to shape and position the iliac crest on to the model prior to placing it on the native scapula.

The patient is placed on the operation room table in the beach-chair position with the head elevated between 30 and 80 degrees, and the ipsilateral iliac crest is exposed. In patients with static subluxation, lower degrees of elevation may help with keeping the humeral head in a more reduced position. To obtain the ICBG, the bolsters along the iliac crest are positioned so as to support the patient, but not to impede access to the iliac crest. An electric/hydropneumatic limb positioner is utilized to manipulate and position the shoulder throughout the procedure. The shoulder, arm, and ipsilateral iliac crest are prepared and draped in the standard sterile fashion.