Randomized controlled study of the efficacy of the injection of botulinum toxin type A versus corticosteroids in chronic plantar fasciitis: results at one and six months.

OBJECTIVE: To determine the efficacy of botulinum toxin type A in chronic plantar fasciitis compared to the local injection of a corticosteroid plus local anaesthetic.

METHODS: Patients with a clinical diagnosis of plantar fasciitis made at least six months earlier were selected to enter a randomized, single-blind study of treatment with injections of botulinum toxin type A or corticosteroid. There were 28 patients in each treatment group. Patients were evaluated at one month using the Foot Health Square Questionnaire and those with no clinical response subsequently received a second injection with the drug of the other arm of the study, creating two new treatment groups. Re-evaluation was performed at six months.

RESULTS: One month after injection there was a clear clinical improvement in both treatment groups but it was greater in the botulinum toxin group, with a significant difference for the pain item (P = 0.069), though not in other items. At six months, patients treated with botulinum toxin type A had continued to improve in all items, whereas the corticosteroid group lost part of the improvement achieved at one month (improvement with botulinum toxin vs. corticosteroid: pain 19.10/-6.84 (P = 0.001), function 16.00/-8.80 (P < 0.001), footwear 13.48/-7.95 (P = 0.004), self-perceived foot health 25.44/-5.41 (P < 0.001).

CONCLUSION: Botulinum toxin type A should be considered for the treatment of chronic plantar fasciitis in view of the improvement found at one month, and particularly at six months, when this treatment clearly has better results than corticosteroid injections. Further studies with larger samples are necessary to confirm these results.