Improved Outcomes With Platelet-Rich Plasma for Treating Extra-articular Hip Pathology Especially Greater Trochanteric Pain Syndrome and Hamstring Injury: A Systematic Review of Randomized Controlled Trials.

Abstract

To perform a systematic review evaluating indications, preparation methods, and outcomes of randomized controlled trials (RCTs) involving platelet-rich plasma (PRP) injections for extra-articular hip pathology. A literature review was performed using the PubMed-MEDLINE, Embase, and Cochrane databases. Only RCTs evaluating extra-articular PRP hip injections were included. Study design, patient and disease characteristics, PRP processing methodology using the Platelet-Activation-White blood cell (PAW) classification, and patient-reported outcomes were analyzed. Study quality was assessed by the revised Cochrane risk-of-bias tool for randomized trials (RoB2). Meta-analyses were performed for studies evaluating the same pathology with comparable outcome metrics. Eleven RCTs (581 hips) were included with a focus on hamstring (five studies, 4 acute muscular injury; 208 patients, 1 chronic proximal tendinopathy; 17 patients), greater trochanteric pain syndrome or abductor tendinopathy (five studies; 263 patients), and piriformis (one study; 60 patients) pathology. PRP yielded superior outcomes compared to control groups for at least one time point in three RCTs (60%) on gluteal tendinopathy and two RCTs (50%) evaluating return to sport rate following acute hamstring injury. Meta-analyses found high heterogeneity (I² = .92) in greater trochanteric pain syndrome (GTPS) studies with a significant treatment effect for the modified Harris Hip Score favoring PRP (P = .005) compared to control groups (P = .08). There was lower heterogeneity for hamstring studies (I² = .65) and a significant treatment effect favoring PRP with an 8-day shorter return to sport (P = .005). All RCTs found improvements in pain and function following PRP injection with clinically relevant outcome thresholds and meta-analyses favoring PRP when treating GTPS and hamstring pathology. While there is substantial heterogeneity in study design, PRP formulations, control groups, outcome metrics, and follow-up time, all reviewed RCTs showed comparable or superior outcomes with PRP compared to controls. Level I, systematic review of Level I randomized controlled trials.