THE EFFECTS OF ARTHROSCOPIC ACROMIOPLASTY ON THE ACROMIOCLAVICULAR JOINT

Thirty patients with 31 shoulders underwent clinical and radiologic ev aluation 5 to 6 years after arthroscopic acromioplasty. The mean age w as 51 years. The acromioclavicular (AC) joint was assessed for tendern ess on palpation and pain on horizontal adduction of the shoulder. All patients underwent a radiologic examination consisting of an anteropo sterior view of he AC joint and bilateral stress views. No patient had superior translation or widening of more than 1 mm of the AC joint on stress views on the unoperated side. On he operated side 12 (38%) sho ulders showed signs of instability consisting of a superior translatio n of the clavicle of 2 to 3 mm, distraction on weight bearing view, or both. No severely osteoarthritic AC joint (grade 3 or 4) was unstable . The degree of osteoarthritis did not differ for both shoulders, sugg esting hat arthroscopic acromioplasty does not accelerate osteoarthrit ic change in the AC joint but can induce instability. Nine patients ha d tenderness over he AC joint and instability on stress views. They ha d a significantly reduced University of California Los Angeles score o f 25 +/- 5 compared with the other patients (29.5 +/- 7). We conclude that preservation of the inferior capsule during arthroscopic acromiop lasty is important for the integrity of the AC joint in patients witho ut severe osteoarthritic changes.