**8.8 Complications**

The most common complication is the recurrence of instability, which may be attributed to diagnostic and technical errors, or to additional trauma. Misdiagnosis may occur when a significant glenohumeral bone loss is not properly evaluated or a multidirectional component escapes diagnosis. Inadequate capsular tensioning and restoration of the glenoid concavity are the commonest technical errors met. It is therefore crucial to reassess range of motion and humeral head alignment after the repair. In athletes, the risk of recurrence increases with return to sports, since the demands placed on the shoulder are analogous to those that caused the initial injury.

Hardware failure commonly involves misplacement of the suture anchors. Absorbable implants have reduced the occurrence of late anchor displacement and complications during revision surgery. However proper anchor placement is mandatory and a careful evaluation should be performed whenever symptoms appear. Osteopenia along the glenoid rim has been correlated with absorbable anchors along with disuse during the postoperative period.

Nerve injury is not common. Structures at risk, however, include the axillary nerve that lies 1-1.5 cm below the inferior glenohumeral capsule and the musculocutaneous nerve situated 5-8 cm below the coracoid. Manipulation at the extremes of the range of motion should be avoided.

A recent concern after arthroscopic instability repair has been chondrolysis (Levine et al, 2005). Although rare, it is devastating because it often requires additional surgery and potentially causes permanent deficits. Intra-articular use of thermal devices, articular pain pumps, and local anesthetics within the articular space, as well as increased articular pressure during surgery have been implicated in the pathogenesis of chondrolysis.
