Effectiveness of Hypertonic Dextrose Injection (Prolotherapy) in Plantar Fasciopathy: A Systematic Review and Meta-analysis of Randomized Controlled Trials

To systematically review the effectiveness of hypertonic dextrose prolotherapy (DPT) in plantar fasciopathy (PF) compared with other non-surgical treatments. PubMed/MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, Allied and Complementary Medicine Database, Global Health, Ovid Nursing Database, Dimensions, and WHO ICTRP were searched from inception to April 30th, 2022. Two independent reviewers selected randomized controlled trials (RCTs) that evaluated the effectiveness of DPT in PF compared with non-surgical treatments. Outcomes included pain intensity, foot and ankle function, and plantar fascia thickness. Two independent reviewers conducted data extraction. Risk of bias (RoB) assessment was conducted using the Cochrane Risk of Bias 2 (RoB 2) tool, and certainty of evidence was assessed with Grading of Recommendation Assessment, Development, and Evaluation (GRADE). Eight RCTs (n=469) met the inclusion criteria. Pooled results favored the use of DPT versus normal saline (NS) injections in reducing pain (weighted mean difference [WMD] -41.72; 95% confidence interval [CI] -62.36 to -21.08; P<.01; low certainty evidence) and improving function [WMD -39.04; 95% CI -55.24 to -22.85; P<.01; low certainty evidence] in the medium term. Pooled results also showed corticosteroid (CS) injections was superior to DPT in reducing pain in the short term [standardized mean difference 0.77; 95% CI 0.40 to 1.14; P<.01; moderate certainty evidence]. Overall RoB varied from "some concerns" to "high". The overall certainty of evidence presented ranges from very low to moderate based on the assessment with the GRADE approach. Low certainty evidence demonstrated that DPT was superior to NS injections in reducing pain and improving function in the medium term, but moderate certainty evidence showed that it was inferior to CS in reducing pain in the short term. Further high-quality RCTs with standard protocol, longer-term follow-up, and adequate sample size are needed to confirm its role in clinical practice.