Serial Ultrasonographic Findings of Plantar Fasciitis After Treatment With Botulinum Toxin A: A Case Study

Chou L-W, Hong C-Z, Wu E-S, Hsueh W-H, Kao M-J. Serial ultrasonographic findings of plantar fasciitis after treatment with botulinum toxin A: a case study.Plantar fasciitis is a common cause of heel pain and is the result of a degenerative process of the plantar fascia at its calcaneal attachment. A case study of a preliminary experience with local injections of botulinum toxin A (BTX-A) for the treatment of chronic plantar fasciitis in a 43-year-old woman is presented. We injected the patient with 70 units of BTX-A (0.7mL) in 2 divided doses: 40 units (0.4mL) in the tender region of the heel, and 30 units (0.3mL) in the most tender point of the foot arch. Visual analog scale (VAS) and pressure pain threshold (PPT) were measured to evaluate the efficacy of BTX-A injections. Real-time, high-resolution ultrasonographic findings of the plantar fascia after BTX-A injections were also used for serial follow-ups. After BTX-A injection, decreased VAS values were reported and increased PPT was observed. In ultrasonographic studies, the thickness of the plantar fascia and the hypoechogenicity of the fascia were reduced. Decreased plantar fascia thickness was observed on the first and third week after BTX-A injections. The findings were compatible with the changes in pain assessed by VAS and PPT. Ultrasonographic findings also indicated a progressive decrease in the thickness of the underlying muscle belly. Ultrasonography seems to be a valuable, noninvasive diagnostic tool for the evaluation of plantar fasciitis treated with BTX-A injections. It can offer objective measurements of therapeutic effects and is feasible for serial follow-ups.