Treatment of pain attributed to plantar fasciitis with botulinum toxin a: a short-term, randomized, placebo-controlled, double-blind study.

OBJECTIVE: To investigate the effect of botulinum toxin A on associated pain and functional impairment of refractory plantar fasciitis.

DESIGN: This is a randomized, double-blind, placebo-controlled study of 27 patients (43 feet) with plantar fasciitis. Block randomization was performed using computer software. In patients with bilateral symptoms of comparable severity, botulinum toxin A was injected in one foot and saline in the other foot. The treatment group received a total of 70 units of botulinum toxin A divided into two sites per foot. One of the two sites was the tender area in the medial aspect of the heel close to the calcaneal tuberosity (40 units), and the other was in the arch of the foot between an inch anterior to the heel and middle of the foot (30 units). The placebo group received the same volume of normal saline. Main outcome measures included: Pain Visual Analog Scale, Maryland Foot Score, Pain Relief Visual Analog Scale, and pressure algometry response. Patients were assessed before injection, at 3 wks, and at 8 wks.

RESULTS: The study revealed statistically significant changes in the treatment group. Compared with placebo injections, the botulinum toxin A group improved in all measures: Pain Visual Analog Scale (P < 0.005), Maryland Foot Score (P = 0.001), Pain Relief Visual Analog Scale (P < 0.0005), and pressure algometry response (P = 0.003). No side effects were noted.

CONCLUSIONS: Botulinum toxin A injection for plantar fasciitis yields significant improvements in pain relief and overall foot function at both 3 and 8 wks after treatment.