BACKGROUND Lateral epicondylitis is a common painful elbow disorder. Several approaches to treatment have been proposed, with a local injection of corticosteroids being the most frequently used. Recent insights into the pathophysiology encouraged the introduction of autologous blood injections as an alternative treatment method. AIM: The aim of this meta-analysis is to summarize quantitatively the evidence regarding the efficacy of
corticosteroids and autologous blood injections for treatment of pain in lateral epicondylitis. DESIGN Meta-analysis. SETTING Outpatient treatment. POPULATION Studies were considered eligible based on the following inclusion criteria: adult human, diagnosis of lateral epicondylitis, randomized controlled trials comparing corticosteroids versus autologous blood injections, pain assessment. Exclusion criteria were previous surgery for lateral epicondylitis or for other elbow disorders, concurrent treatment with drugs or physiotherapy, diagnosis of musculoskeletal systemic disorder. METHODS A systematic search of literature was performed according to PRISMA statement. Effect size of each included study was calculated and analyzed in a random-effects model. RESULTS Four studies, enrolling total of 218 patients (139 females and 79 males), were included in quantitative analysis. At 2 weeks there was a trend towards a reduction of VAS score in the corticosteroid group (WMD = 2.12 [95% CI: 4.38 to 0.14], P=0.07). No significant differences were recorded in the medium-term (4-12 weeks; WMD = 0.85 [95% CI: -0.44 to 2.15], P= 0.19) and long-term (24 weeks; WMD = 0.63 [95% CI: -2.40 to 3.66], P= 0.68) follow-up. CONCLUSIONS Few high-quality trials compare the efficacy of corticosteroid and autologous blood injections in the control of pain related to lateral epicondylitis. Available data indicate that corticosteroids tend to reduce VAS score in short-term follow-up, although these data are not statistically significant. No differences were recorded in the medium and long term. CLINICAL REHABILITATION IMPACT Contrary to popular opinion among medical professionals, and despite pathophysiological cues, the currently available data offer no support for the effectiveness of autologous blood injections in medium- and long- term follow-up. Further studies are necessary to establish which treatment has more impact on pain in lateral epicondylitis. These data could be then used as a basis for practical guidelines and new protocols of treatment.