We evaluated 67 shoulders in 65 patients who had pain and dysfunction for more than two years after an initial acromioplasty for impingement syndrome without a rotator cuff tear. In addition to a thorough history, physical examination, local anaesthesia injection and any other necessary investigations all patients had arthroscopic evaluation of the shoulder. In 27 shoulders there had been diagnostic errors, and in 28 operative errors; only in 12 had the diagnosis and the operative procedure both been correct. Subsequent operative intervention in patients not receiving worker's compensation benefit had a 75% success rate, whereas in those receiving such benefits the success rate was only 46%.

Arthroscopic surgery of the shoulder was performed on 439 patients over a 10-year period: these patients are reviewed after a minimum follow-up of one year. Diagnostic arthroscopy is known to be valuable and we have found that arthroscopic surgery also is safe and effective. It was useful in treating frozen shoulder, early osteoarthritis, isolated tears of the glenoid labrum and lesions of the biceps tendon. It was less useful in treating partial tears of the rotator cuff, tendonitis and severe osteoarthritis, and of little value in treating complete tears of the rotator cuff or in treating patients in whom previous operations on the rotator cuff had failed. It may prove to be a useful method of performing synovectomy in rheumatoid arthritis and of treating instability.