Abstract
BACKGROUND: Previous meta-analyses have been conducted to compare outcomes of various treatment injections for lateral epicondylitis (LE), including corticosteroid injection (CSI) and autologous blood products such as autologous blood (AB) and platelet-rich plasma (PRP). PURPOSE: To conduct a systematic review of overlapping meta-analyses comparing different injection treatments (CSI, AB, PRP) for LE to determine which meta-analyses provide the best available evidence. STUDY DESIGN: Systematic review; Level of evidence, 2. METHODS: A systematic review was performed by searching PubMed, Embase, and the Cochrane Library to locate meta-analyses that compared clinical outcomes of CSI, AB, and PRP for the treatment of LE. Search terms included "injection," "corticosteroid," "platelet-rich plasma," "autologous blood," "tennis elbow," "lateral epicondylitis," and "meta-analysis." Results were reviewed to determine study eligibility. Patient outcomes were extracted from these meta-analyses. Meta-analysis quality was assessed with the Oxman-Guyatt and Quality of Reporting of Meta-analyses (QUOROM) systems. The Jadad decision algorithm was then used to determine which meta-analyses provided the best level of evidence. RESULTS: Nine meta-analyses (two level 1 studies, seven level 2 studies) containing 8656 patients met the eligibility criteria. Seven meta-analyses found that autologous blood products such as AB and PRP significantly improved pain and elbow function in the intermediate term (12-26 weeks), while 4 studies found that CSI effectively relieved pain and improved elbow function in the short term (<12 weeks). The study by Arirachakaran et al in 2016 received the highest QUOROM and Oxman-Guyatt scores; therefore, this meta-analysis appears to have the highest level of evidence. In addition, this study was rated the highest-quality study in this systematic review according to the Jadad decision algorithm. Lower-quality meta-analyses indicated that dosage, number of injections, and differences in therapeutic duration between CSI and autologous blood products may be essential factors in determining the appropriate treatment injection protocol for LE. CONCLUSION: The current best available evidence suggests that CSI improves functional outcomes and pain relief in the short term, while AB and PRP are the most effective treatments in the intermediate term.