Effects of intra-articular Platelet-Rich Plasma (PRP) injections on osteoarthritis in the thumb basal joint and scaphoidtrapeziotrapezoidal joint.

Intra-articular injection of platelet rich plasma (PRP) has been reported to decrease pain and improve function in knee osteoarthritis. There are few reports on the effect of PRP in the treatment of osteoarthritis in the hand. Our aim was to evaluate the effect of PRP-injections on pain and functional outcome in the short-term for osteoarthritis in the thumb basal joint and scaphoidtrapeziotrapezoidal (STT) joint. A retrospective analysis was performed of 29 patients treated with intra-articular PRP injection for painful osteoarthritis in the thumb basal joint (21 patients) or STT joint (eight patients). The patients received two consecutive, radiologically guided PRP injections at an interval of 3-4 weeks. Pain at rest and on load (numerical rating scale (NRS) 0-10), Patient-rated Wrist and Hand Evaluation (PRWHE) score (0-100), grip strength (Jamar) and key pinch were recorded pre-injection and 3 months after the second injection. Mean age was 63 (range 34-86) years and 17 patients were women. We used generalized estimating equations (GEE) to analyze the effect on the outcome variables. Possible predictors were included in the model (high pain level pre-injection, gender, age, manually demanding work, affected joint (thumb base or STT) and use of analgesic). The GEE analysis showed that PRP injections had no effect on reported pain, PRWHE score, grip strength or key pinch. 16/28 patients experience a positive effect according to a yes/no question. The short-term effect of PRP for osteoarthritis in the thumb base and STT-joint is doubtful and needs to be properly investigated in placebo-controlled studies.