RESUMO
OBJECTIVE: Plantar fasciitis (PF) is one of the most common causes of heel pain. The affected area is often close to the attachment of plantar fascia to calcaneus bone. The purpose of this study was to compare the effects of ozone (O2-O3) injection to corticosteroid injection under ultrasound guidance for the treatment of chronic PF. DESIGN: Randomized clinical trial. SETTING: Academic University and Neuromusculoskeletal Research Center. SUBJECTS: Thirty patients with chronic PF. METHODS: The patients were randomly divided into two groups receiving methylprednisolone (15 subjects) vs ozone (O2-O3; 15 subjects). The following outcome measures were assessed before injection and then two weeks and 12 weeks after the injection in each group; morning and daily pain via visual analog scale, daily life and exercise activities via the Foot and Ankle Ability Measure, and plantar fascia thickness at insertion and 1 cm distal to its insertion into the calcaneus via ultrasound imaging. RESULTS: Intragroup changes showed significant improvement in pain, functional parameters, and sonographic findings in both groups (P < 0.05). Pain reduction (both daily and morning) and daily activity improvement were better in the corticosteroid group two weeks after injection; however, at 12 weeks, the ozone (O2-O3) group had significantly more improvement (P = 0.003, P = 0.001, and P = 0.017, respectively). CONCLUSIONS: Both methods were effective in the treatment of chronic PF. Steroid injection provided a more rapid and short-term therapeutic effect. However, ozone (O2-O3) injection led to a slow and longer-lasting treatment outcome. Ozone (O2-O3) injection can be an effective treatment, with slow onset and a longer durability in the treatment of chronic PF.