Medium-term clinical results after operative and non-operative treatment of subacromial impingement

Treatment of subacromial outlet impingement can be operative or non-operative. The purpose of this prospective study was to compare the results of these two types of treatment over a fairly long period. To this end, 72 patients suffering from grade II outlet impingement were prerandomized into two different groups. Group I was made up of 32 patients who were treated operatively; the 40 patients in group II underwent a nonoperative treatment. Follow-up time was 4 years for both groups. Depending on the surgeon an arthroscopic subacromial decompression according to Ellman or an anterior acromioplasty according to Neer was performed in each patient in group I. During a 2-week hospital stay a non-operative treatment was administered to all patients in group Il. Before the sta rt of treatment patient evaluation was performed: clinical examination, transscapular, a. p. and oblique X-rays, ultrasonography and the IA test; in addition, the Subjective Shoulder Rating Scale (SSRS) was used. This is basically a modification of the Constant-Murley Scoring System. The patients were familiarized with the SSRS sheet before starting the treatment, The sheet was mailed to the patients for then to evaluate their shoulders al yearly intervals. The median total score in group I started from a lower level, with 54 points. The nonoperativ median total score in group II started at 59 points. During the 4-year follow-up the improvement in the operatively treated shoulders was 30 points and that in the nonoperatively treated shoulders, 15 points. Over the years there was a tendency for the operatively treated shoulders to improve. The pain score in group I improved from 10 points preoperatively to 25 points 1 year postoperatively and to 30 points in the 2nd, 3rd and 4th years after the operation. In group II the pain score declined. An increase of 5 points was found in the first 2 years after starting the treatment, and the same score, 20 points, as at the sta rt was found in the 3rd and 4th years. The range of motion changed from 20 to 30 points only in group I. The activity score paralled the range of motion. Ability to work overhead was consistently reduced throughout the follow-up period and was not influenced by the treatment received. Instability was not a problem for these patients. There was no change in the scores in the two groups. In summary, both forms of treatment led to an improvement of the subacromial impingement. The improvement in pain was the most marked. The long-term results are required for the final evaluation, because results tend to change after both operative and non-operative treatment. In addition, clinical examination and diagnostic imaging techniques should be applied and are necessary to find the reasons for this change.