Terapia de ondas de choque focal para osteoartrose de joelho: um ensaio clínico randomizado duplo-cego

Abstract

Objective: To assess the efficacy of focused extracorporeal shockwave therapy (f-ESWT) when compared to placebo for pain and disability in patients with knee osteoarthritis (OA). Methods: Randomized, parallel, double-blind, placebo-controlled clinical trial. Patients with primary knee OA were given a set of exercises (hamstring stretching and quadriceps strengthening) and randomized into f-ESWT or placebo (sham probe). All patients were submitted to 4 weekly sessions of 7,000 pulses, and in the f-ESWT group energy was up to 0.15mJ/mm2. Primary outcome was visual analog scale (VAS) for pain at 1 month. Secondary outcomes were WOMAC, TUG, Lequesne's index and OMERACT-OARSI responder index at 1 and 3 months; as well as VAS at 3 months and adverse events (AEs). Both patients and outcome assessors were blinded. Mann-Whitney U test and Fisher's exact test were used with alpha=5% and power=80% in an intention-to-treat analysis. Continuous outcomes were reported as mean± standard deviation. Results: 18 patients were included (9 in each group), aging 60.6±8.7, with 33.3% males. There was no significant difference at baseline across groups in any variables. f-ESWT was not superior to placebo at 1 month: VAS=-2.97±3.18 and -2.68±2.33cm, respectively, p=0.96. TUG at 1 month had significant differences: 9.09±2.30 and 11.01±2.85sec, p=0.01. No serious AEs were observed. Conclusions: f-ESWT was not superior to placebo for knee OA. This RCT was underpowered to detect differences in this study. New RCTs should use WOMAC A (pain subscale) as primary outcome and recruit at least 92 patients.