RESUMO
OBJECTIVE: 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. DATA SOURCES: 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. STUDY SELECTION: 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 EXTRACTION: Data were extracted independently and in duplicate using a standardized data extraction format. Information was contrasted by a third observer. DATA SYNTHESIS: 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. CONCLUSIONS: This meta-analysis suggests both a statistically significant and a clinically meaningful improvement on plantar fasciitis symptoms after BTX-A treatment.
