Clinical Efficacy of Botulinum Toxin in the Treatment of Plantar Fasciitis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

To evaluate the efficacy of botulinum toxin A (BTX-A) for the treatment of plantar fasciitis through a meta-analysis of randomized controlled trials (RCTs) focusing on pain and functional outcomes since current literature has supported a potential benefit of BTX-A. The MEDLINE, EMBASE, Web of Science, and Scopus databases were searched until December 2020 for RCTs reporting the effects of BTX-A injections on plantar fasciitis. The complementary literature search included Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and greylit.org. Only RCTs assessing the effect of BTX-A injections on pain, functional improvement, or plantar fascia thickness in patients with plantar fasciitis were included. Multiple researchers carried out the screening process of the 413 records. Data were extracted independently and in duplicate using a standardized data extraction format. Information was contrasted by a third observer. BTX-A injections resulted in significant pain relief (mean difference, −2.07 [95% CI, −3.21 to −0.93]; P=.0004; I2=97%) and functional improvement (standardized mean difference, 1.15 [95% CI, 0.39-1.91]; P=.003; I2=87%). A subanalysis indicated that pain relief was sustained at 12 months while functional improvement remained significant after 0-6 months. The results were not affected by a single study after sensitivity analysis. The site of injection and the use or not of ultrasound-guided injections may account for potential sources of interstudy heterogeneity. This meta-analysis suggests both a statistically significant and a clinically meaningful improvement on plantar fasciitis symptoms after BTX-A treatment.