Correlation between Results of Preoperative Impingement Test and Clinical Outcomes after Arthroscopic Rotator Cuff Repair

Background: The aim of the present study was to determine the correlation between the amount of pain reduction after local anesthetic injection into the subacromial space preoperatively and clinical outcome after arthroscopic rotator cuff repair. Methods: A total of 127 patients who underwent arthroscopic rotator cuff repair and followed up at least 1 year were analyzed retrospectively. Preoperatively, a visual analogue scale (VAS) for pain was measured in all patients before and after the ultrasound guided impingement test. The participants were divied into four groups according to pain reduntion ater impingement test (Group A: >75%, Group B: 50%-75%, Group C: 25%-50%, Group D: <25%). VAS for pain, shoulder range of motion, shoulder isometric strength, ASES score were evaluated preoperatively and at 3, 6, 9, and 12 months postoperatively. Results: After surgery, the amount of pain reduction shows significantly at 3, 6 months in Groups A, B as compared to Groups C, D (p<0.05). Among the range of motion of shoulder joint, forward flexion was significantly improved in Group A at 3 months (p<0.05). The ASES score significantly improved at 3, 6 months in Groups A, B as compared to Group C, D (p<0.05). Conclusions: Preoperative degree of pain reduction after impingement test correlates with the improvement of pain after arthroscopic rotator cuff repair, especially in the early phase. Therefore, the impingement test could be effectively used.