Platelet-rich plasma versus steroid injection for subacromial impingement syndrome

Abstract

Purpose: To compare the 6-week and 6-month outcome in 60 patients who received a single-dose injection of platelet-rich plasma (PRP) or steroid for subacromial impingement syndrome (SIS).

Methods: 22 men and 38 women (mean age, 49.7 years) opted to receive a single-dose injection of PRP (n=30) or steroid (n=30) for SIS that had not responded to conservative treatment for >3 months. The PRP or a mixture of 1 ml 40 mg methylprednisolone and 8 ml prilocaine was administered via a dorsolateral approach through the interval just beneath the dorsal acromial edge. Both groups were instructed to perform standard rotator cuff stretching and strengthening exercises for 6 weeks. The use of non-steroid anti-inflammatory drugs was prohibited. Patients were evaluated before and 6 weeks and 6 months after treatment using the Constant score, visual analogue scale (VAS) for pain, and range of motion (ROM) of the shoulder.

Results: No local or systemic complication occurred. Improvement in the Constant score and VAS for pain at week 6 and month 6 was significantly better following steroid than PRP injection. The difference in the Constant score was greater than the mean clinically important difference of 10.4. Nonetheless, the 2 groups were comparable for improvement in ROM of the shoulder.

Conclusion: Steroid injection was more effective than PRP injection for treatment of SIS in terms of the Constant score and VAS for pain at 6 weeks and 6 months.

Keywords: platelet-rich plasma; shoulder impingement syndrome; steroids.