Plasma versus autologous whole blood in the treatment of lateral epicondylitis: A systematic review and meta-analysis of randomized clinical trials

Background To compare platelet-rich plasma and autologous whole blood in adults with lateral epicondylitis, evaluating functional improvement and pain reduction across follow-up periods. Methods Randomized clinical trials enrolling adults with clinically confirmed lateral epicondylitis and a minimum symptom duration of three months were systematically identified by searching PubMed, ScienceDirect, and the Cochrane Central Register of Controlled Trials. Functional improvement was prespecified as the primary outcome, whereas pain was the secondary outcome. Pooled effect estimates were obtained using random-effects meta-analyses conducted with Review Manager (RevMan) version 5.4.1, and between-study heterogeneity was quantified using the I 2 statistic. Sensitivity analyses were performed to assess robustness in scenarios of substantial heterogeneity or when individual trials exerted excessive influence. The study protocol was prospectively registered in PROSPERO (CRD420250655318). Results Four randomized clinical trials involving 322 participants were included, with 167 receiving platelet-rich plasma. Follow-up ranged from 1 to 12 months for function and 1 to 6 months for pain. No significant differences were observed between platelet-rich plasma and autologous whole blood for function, although a non-significant early trend favoring platelet-rich plasma was not sustained over time, with heterogeneity between 11% and 67%. Subgroup analysis showed no heterogeneity across follow-up durations (χ 2 = 1.96; df=3; p=0.58; I 2 = 0%). Pain reduction appeared greater with platelet-rich plasma when all studies were pooled; however, this difference disappeared after exclusion of a single high-risk-of-bias study, with heterogeneity decreasing to null levels except for low heterogeneity (25%) at six months. This indicates that pain outcomes were sensitive to an individual trial. Conclusion Platelet-rich plasma did not demonstrate statistically significant superiority over autologous whole blood for functional outcomes, although a non-significant tendency favoring platelet-rich plasma was observed in early follow-up. Given the limited number of included studies, these findings should be interpreted with caution and considered exploratory.