Recurrent anterior shoulder instability in patients over 40 years old presents a difficult therapeutic problem when it is associated with an irreparable rotator cuff tear. This type of anterior instability, which is mainly secondary to the loss of the posterior check rein, was initially described by McLaughlin and was described by Craig as “instability from the posterior mechanism” whereby the intact anterior labrum and capsule act as a hinge while the humeral head rolls over the anterior glenoid rim. The Trillat procedure stabilizes the shoulder by placing the conjoint tendon closer to the glenohumeral joint and lowering the subscapularis, using the same dynamic “sling effect” as the Latarjet procedure. Furthermore, the arthroscopic technique is easier (i.e., no need to pass the bone block through the subscapularis muscle) and safer (i.e., no pectoralis minor detachment) than the Latarjet procedure.

The Trillat procedure consists of performing a closed-wedge osteotomy of the coracoid, which is tilted downward, posteriorly, and medially and then fixed to the glenoid neck with a nail or screw implanted above the subscapularis. The procedure stabilizes the shoulder by placing the conjoint tendon closer to the glenohumeral joint and lowering the subscapularis using the same dynamic “sling effect” (or “seat belt effect”) as the Latarjet procedure.