Early degenerative joint disease simulating impingement syndrome: arthroscopic findings.

Eighteen patients who underwent shoulder arthroscopy for impingement syndrome were shown at operation to have coexisting glenohumeral degenerative joint disease (DJD) which was not apparent during preoperative clinical and radiographic evaluation. Because traditional ("open") techniques of anterior acromioplasty do not allow inspection of the glenohumeral joint, it is almost certain that this pathology would have been missed at operation if open acromioplasty had been performed. We conclude that arthroscopic subacromial decompression (ASD), by allowing easy inspection of the glenohumeral joint, offers a distinct advantage over traditional acromioplasty. Furthermore, arthroscopic evaluation of some of these patients' glenohumeral joints provided us with evidence supporting the existence of subluxation arthropathy. We have also developed a new clinical test, the "compression-rotation" test, which has been helpful in distinguishing patients with both impingement syndrome and early DJD syndrome from those with isolated impingement syndrome. Although patients in this study appeared to be doing well at short-term follow-up status post-ASD and glenohumeral debridement, no long-term results are yet available.