Abstract
The acromion is a bony process that juts out from the lateral end of the scapular spine. It is continuous with the blade and the spinous process. The process is rectangular, and carries a facet for the clavicle. Inferiorly is sited the subacromial bursa. Inferior encroachment or displacement of the acromion can result in impingement.
The aim of this osteological study was to assess the presence of acromial displacement and variations predisposing to compaction of the subacromial space. Using the method described by Morrison and Bigliana, we assessed the scapulae of 128 men and women ranging from 35 to 92 years of age. We found a flat acromion in 30%, no hook in 48%, a small hook in 18% and a large hook in 4%. The presence of a hook was associated with a subacromial facet and a large hook with glenoid erosion.
This study confirms the presence of four types of acromion.
The abstracts were prepared by Professor M. B. E. Sweet. Correspondence should be addressed to him at The Department of Orthopaedic Surgery, Medical School, University of Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
