Treatment of Morton neuroma with botulinum toxin A: a pilot study.

BACKGROUND AND OBJECTIVE: Morton neuroma is a common cause of metatarsalgia of neuropathic origin. Systematic reviews suggest that insufficient studies have been performed on the efficacy of the different treatments available. OnabotulinumtoxinA has shown a degree of usefulness in other conditions associated with neuropathic pain. The aim of this study was to investigate the therapeutic potential of onabotulinumtoxinA in Morton neuroma. PATIENTS AND METHODS: We present an open-label, pilot study with 17 consecutive patients with Morton neuroma and pain of more than 3 months' duration that had not responded to conservative treatment with physical measures or corticosteroid injection. Patients received one onabotulinumtoxinA injection in the area of the neuroma. The main outcome measure was the variation in the pain on walking evaluated using a visual analogue scale (VAS) before treatment and at 1 and 3 months after treatment. The secondary outcome was the change in foot function, which was assessed using the Foot Health Status Questionnaire. RESULTS: In the overall group, the mean initial VAS score on walking was 7. This mean score had fallen to 4.8 at 1 month after treatment and to 3.7 at 3 months. Twelve patients (70.6 %) reported an improvement in their pain and five patients (29.4 %) reported no change; exacerbation of the pain did not occur in any patient. Improvements were also observed in two of the dimensions of the Foot Health Status Questionnaire: foot pain, which improved from a mean of 38.88 before treatment to 57 at 3 months, and foot function, which improved from a mean of 42.27 before treatment to 59.9 at 3 months. Clinical variables including age, sex, site and size of the lesion, standing activity, weekly duration of walking, footwear, foot type and footprint had no influence on the outcome. No adverse effects were reported. CONCLUSIONS: In this pilot study, injection with onabotulinumtoxinA was shown to be of possible usefulness to relieve the pain and improve function in Morton neuroma. This finding opens the door to further clinical research.

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.