Background: It remains unclear whether application of local anesthesia (LA) interferes with clinical efficacy of extracorporeal shock wave therapy (ESWT) for chronic plantar fasciitis.
Aims: To evaluate the effect of local anesthesia on the clinical outcome after repetitive low-energy ESWT for chronic plantar fasciitis.
Methods: Eighty-six patients with chronic plantar fasciitis were randomly assigned to receive either low-energy ESWT without LA, given weekly for three weeks (Group I, n=45; 3 x 2000 pulses, total energy flux density per shock 0.09 mJ/mm2) or identical ESWT with LA (Group II, n=41). Primary outcome measure was: Reduction of pain from baseline to month 3 post-treatment in a pain numeric rating scale [0-10 points] during first steps in the morning, evaluated by an independent blinded observer. Calculations were based on intention-to-treat.
Results: No difference was found between the groups at baseline. At 3 months, the average pain score was 2.2+/-2.0 points for patients of Group I, and 4.1+/-1.5 points for patients of Group II. The mean between-group difference was 1.9 points (95% CI: [1.1-2.7 points]; P<.001). Significantly more patients of Group I achieved 50% reduction of pain compared to Group II (67% vs 29%, P<.001).
Conclusion: ESWT as applied should be done without LA in patients suffering from chronic heel pain. LA applied prior treatment reduced the efficiency of low-energy ESWT.