Abstract
Biopsies from the subacromial bursa were obtained from 30 patients with an impingement syndrome and from an autopsy series of 13 “normal” shoulders. Bursal fibrosis seemed to be a characteristic of the patient group; inflammatory cells, found in 7/30 specimens from the patients, were not found in the autopsy series. The microscopic findings could not be predicted from peroperative observations. There was an association between a poor outcome of surgery and absence of bursal fibrosis.