Injection therapies in muscle injuries: A systematic review

Objective: Injection therapies are widely used as a treatment option in sports and musculoskeletal medicine, but with limited evidence. The aim of this systematic review was to review the literature to identify the different injection therapies used, their purpose and to suggest future areas of research. Methods: The following databases were searched up to April 2015 to identify studies using injection therapies for patients with muscle injuries: Medline via PubMed, CINAHL via EBSCO, Cochrane Library, SportDiscus via EBSCO, and Google Scholar. Results: A systematic search of all electronic databases identified 1177 articles. Ten studies on different injection treatments of acute muscle injuries were included: two studies on Actovegin, two on corticosteroid, five on platelet-rich plasma (PRP) and platelet-derived growth factor, and one on autologous conditioned serum. Five studies were randomized control trials (RCTs). Two studies on PRP injection were single case studies and two were case series. All studies included the time to return to sport or to competitive training as an outcome measure. In five studies, the intervention was compared to a control group. All studies reported the positive outcomes of the injection treatment or no effect. No side effects were reported in any publications after the intervention. Conclusion: More research has been published recently into the use of PRP in muscle injuries: one placebo controlled RCT using PRP concluded it to be no better than placebo. It is hard to compare different injections therapies due to different solutions, volumes and times between injections being used. Hence, more highquality trials with standard treatment and rehabilitation protocol are warranted, including a reliable and valid outcome measure to evaluate clinical outcomes being needed.