The relationship between clinical outcomes and the amount of arthroscopic acromial resection.

Purpose: In 47 consecutive patients who had a shoulder impingement syndrome treated by arthroscopic subacromial decompression, we compared the functional outcome with the amount of the acromion resection.

Type Of Study: Prospective study.

Methods: The inclusion criteria for patient selection was a chronic impingement syndrome unresolved by conservative treatment with an intact rotator cuff or with an irreparable rupture of the rotator cuff. The assessment was performed with the scoring system of Constant preoperatively and postoperatively. Quantitative measurements of the acromion resection were made by comparing preoperative and postoperative anteroposterior radiographic views, standardized under fluoroscopic control in order to become reproducible and comparable. There were 39 patients (41 shoulders) available for follow-up at 37 months.

Results: The condition of the shoulder, concerning pain, motion and activities, was improved at the time of follow-up, the mean gain of the total functional score was 29 points/100. Age, side, activity, duration of pain before procedure and cuff statement had no influence on preoperative and postoperative Constant's score. The difference between preoperative and postoperative measurements of anterior acromion protuberance was significant. There was no correlation between the amount of the acromion resection and the improvement of Constant's score (P =.84).

Conclusions: The origin of impingement syndrome is multi-factorial, and efficiency of arthroscopic decompression may not be only due to the amount of acromion resection. From these results and a literature review, this study analyzes several morphologic factors, which could explain the good results of arthroscopic subacromial decompression in impingement syndrome.