Botulinum toxin type A in chronic plantar fasciitis: clinical effects one year after injection

Objective: To determine whether the efficacy of botulinum toxin type A in chronic plantar fasciitis was maintained for more than six months after treatment. Design: Observational follow-up study. Subjects: Twenty-four patients who received botulinum toxin type A injection in a previous randomized study of chronic plantar fasciitis (active treatment group) and who presented a benefit one month after treatment. Methods: A visual analogue scale for pain and the Foot Health Status Questionnaire were used to re-evaluate results 12 months after the botulinum toxin injection. No further injections of botulinum toxin had been administered during the follow-up period. Patients were also asked to give a subjective assessment of treatment outcome. Results: At 12 months, compared with the six-month evaluation, there was a further improvement in foot pain measured using the visual analogue scale, though this did not reach significance (1.78 at 6 months versus 1.22 at 12 months; P = 0.142). However, there were significant improvements in two domains of Foot Health Status Questionnaire: foot pain (91.11 at 6 months versus 80.00 at 12 months; P = 0.001) and foot function (96.19 at 6 months versus 89.38 at 12 months; P = 0.047). There was a small, non-significant deterioration in the shoe and foot health domains. Satisfaction with the outcome was good or very good in the large majority of patients. Conclusions: In patients with chronic plantar fasciitis, the positive effect detected six months after treatment with botulinum toxin type A was maintained at 12 months and there was a further improvement in pain and foot function.