Arthroscopic subacromial decompression. An anatomical study.

Anterior acromioplasty as described by Neer has been an effective procedure for shoulder impingement syndrome. Recent presentations by Ellman suggest that an effective acromioplasty may be performed arthroscopically. These clinical reports have not been supported by any laboratory experience. The purpose of our study was to examine the feasibility and attempt to quantitate the results of arthroscopic subacromial decompressions. Six acromioplasties were performed according to the recommended technique of Dr. Neer to create a standard for comparison. Fourteen fresh postmortem specimens were studied. In seven shoulders a standard acromioplasty was performed with an osteotome. In seven shoulders an acromioplasty was performed using standard arthroscopic approaches and motorized instruments. In five shoulders an isolated division of the coracoacromial ligament was performed arthroscopically. The coracoacromial ligament was completely divided in all five cases. In the osteotome group adequate bone was resected in 75% (21/28) measured locations. In the arthroscopic group adequate bone was removed at 86% (24/28) location. This difference is not statistically significant. In the cadaver, anterior acromioplasty was performed effectively and predictably with arthroscopic instruments. This compared favorably to a conventional osteotome acromioplasty. It was concluded that coracoacromial ligament division can be accomplished.