A preoperative scoring system to select patients for arthroscopic subacromial decompression.

BACKGROUND This study investigated the clinical and radiographic factors that influence outcome after arthroscopic subacromial decompression (ASAD) for shoulder impingement syndrome. The goal was to develop a new preoperative scoring system to identify patients who would have a prompt and sustained benefit from ASAD. METHODS We prospectively reviewed 112 consecutive patients with impingement syndrome who subsequently underwent ASAD. The Oxford Shoulder Score (OSS) was recorded preoperatively and 3 and 12 months postoperatively. A statistically significant improvement in OSS at 3 months after surgery was considered a good outcome. RESULTS The variables associated with good outcome were shoulder pain with overhead activities, persistent symptoms for more than 6 months, symptoms persistent despite a 3-month course of supervised physiotherapy, consistently positive Hawkins test result, radiologic changes of impingement on both acromion and humerus in the subacromial region, and improvement for more than 1 week after a steroid injection. These 6 criteria were combined into a single score for this study, termed the preoperative score (PrOS). Sixty-two patients who had been symptomatic for 1 year with a preoperative score of 5 to 6 showed significant improvement in OSS at 3 months after surgery (P < .001). Thirty-eight patients with a score 3 to 4 had no statistically significant improvement in OSS at 3 months but had a further slight improvement at 1 year. Twelve patients with a score of ≤2 had no significant improvement in OSS at 3 months or 1 year. CONCLUSION This scoring system can identify patients who would have a prompt benefit from ASAD. The impact of surgery in patients with a PrOS of ≤4 points is questionable.