The effect of dextrose prolotherapy versus placebo/other non-surgical treatments on pain in chronic plantar fasciitis: a systematic review and meta-analysis of clinical trials

Background Prolotherapy is the injection of a small volume of sclerosing or irritant solutions into an injured tissue. We aimed to investigate the effect of dextrose prolotherapy (DPT) versus placebo/other non-surgical treatments on pain in chronic plantar fasciitis. Methods We searched seven electronic databases (PubMed/MEDLINE, Web of Science, EMBASE, Scopus, ProQuest, CENTRAL, PEDro) from inception to December 31, 2021 with no language restriction for publications comparing the effect of DPT with placebo/other non-surgical treatments in patients with chronic plantar fasciitis. Our primary outcome was pain and the secondary outcomes were foot function and plantar fascia thickness. The risk of bias was assessed using the Cochrane Collaboration’s tool. Results Overall, eight studies with a total of 449 patients were included in the meta-analysis. All the included studies reported short-term pain. A large effect size (dppc2 = -0.97, 95% confidence interval [CI] -1.84 to -0.10) was observed favoring the use of DPT to reduce pain in patients with chronic plantar fasciitis in the short-term. The results for foot function improvement (dppc2 = -1.28, 95% CI -2.49 to -0.07) and plantar fascia thickness reduction (dppc2 = -1.02, 95% CI -1.99 to -0.05) in the short-term were also in favor of DPT. Conclusions Since almost all the included studies had high risk of bias and multiple trials lacked long-term follow-ups, further high-quality research is required to determine the long-term effects of DPT vs placebo/other non-surgical interventions.