Abstract
Context: Published data on extracorporeal shock wave therapy (ESWT) for chronic plantar fasciitis provide controversial evidence about the clinical relevance and effectiveness. Treatment parameters have significant influence on outcome and optimal treatment protocols have to be determined.
Objective: To assess the effect size and safety of ESWT compared to placebo in the treatment of chronic painful heel syndrome with a new electromagnetic device and an optimized protocol.
Design, Setting, and Participants: Prospective, double-blind, randomized, placebo-controlled trial conducted among 40 patients. Interventions: ESWT (0.25 mJ/mm2) or placebo without anesthesia. Both groups received 3 treatments of 2000 shock wave impulses, each session 1 week apart. Main Outcome Measures: The primary outcome was the percentage change of heel pain quantified by VAS composite score 12 weeks after the last intervention compared to baseline. Secondary endpoints were defined as changes of single VAS scores (morning pain, pain at daily activities and pain with force-meter application), success rates and changes in Roles and Maudsley score.
Results: ESWT resulted in a 73.2% reduction of heel pain regarding the primary endpoint VAS composite score compared to baseline, being 32.7% superior to placebo. Effect size reached clinical relevance (Mann-Whitney effect size (MW) = 0.6737; 0.6400 being the benchmark for medium-sized, relevant superiority, p = 0.0302 single-sided). With regard to the percentage changes of the single VAS scores and the Roles and Maudsley score, the effect size denoted relevant superiority of the ESWT as well (all MWs ≥ 0.6400). No relevant adverse events occurred.
Conclusion: The results of the present study advocate ESWT for refractory painful heel syndrome demonstrating clinically relevant effect sizes. Specific treatment protocols with proven effectiveness ought to be used in the clinical setting.
Correspondence should be addressed to Ms Larissa Welti, Scientific Secretary, EFORT Central Office, Technoparkstrasse 1, CH-8005 Zürich, Switzerland