[Arthropathy of instability. Causes, treatment options and results]

Glenohumeral arthritis may develop after primary or recurrent shoulder dislocation or after surgery for stabilization. Postoperatively, the incidence is reported to be from 12% to 62%, depending on different risk factors. There is no certain correlation between the surgical technique and the rate of arthrosis. Capsulorraphy arthropathy is biomechanically and clinically a well defined entity. The risk of developing severe arthrosis of the shoulder following dislocation of the shoulder is between 10 and 20 times greater in comparison to the normal population. Risk factors are the age during the first episode of instability, the age at instability surgery, bony lesions on the humeral head or the glenoid and rotator cuff tears.For mild stages of glenohumeral arthritis, arthroscopic revision with removal of intraarticular metallic parts, arthroscopic debridement or arthroscopic arthrolysis of an internal rotation contracture might be sufficient. For more severe stages mobilization of the internal rotation contracture and glenohumeral arthroplasty are indicated. With sufficient integrity of the head and glenoid, a surface replacement is adequate. With intact rotator cuff and without bone graft the results for shoulder arthroplasty are comparable to those following primary omarthrosis. With a bone graft at the glenoidal side the risk for implant loosening is 10 times greater. For the functional outcome the quality of the rotator cuff, i.e. the fatty degeneration, is more predictive than the type of previous surgery or the preoperative external rotation contracture.