Sonography of plantar fibromatosis

Plantar fibromatosis is a rare benign fibroproliferative disorder of the plantar fascia that can be evaluated on sonography. Our study details the sonographic appearances of plantar fibromatosis.

We conducted a retrospective review of the clinical presentation, sonographic appearances, and clinical progress in 14 patients (range, 35-85 years; mean age, 53.1 years;) with plantar fibromatosis. Sonography was performed using either a 13-5-MHz multidimensional or 12.5-MHz linear array transducer. The location, sonographic appearances, and size of the plantar fibromatosis nodules were noted and correlated with symptom duration and clinical outcome.

A total of 25 fibromatosis nodules in 19 feet were examined. On sonography, plantar fibromatosis was seen as a discrete fusiform nodular thickening of the plantar fascia, separate from the calcaneal insertion. Approximately one third (36%) of lesions were bilateral, and one quarter (26%) were multiple. All lesions were located either medially (60%) or centrally (40%) in the fascia. Most were hypoechoic (76%), were well defined (64%), and showed no acoustic enhancement (80%) or intrinsic vascularity (92%). No correlation was found between the echogenicity and size of plantar fibromatosis nodules or duration of symptoms (p < 0.01). One quarter of the affected feet had coexistent thickening of the plantar fascia at the calcaneal insertion with no related symptoms.

Although the sonographic appearances of plantar fibromatosis vary, the appearances are characteristic enough to allow a specific diagnosis to be made. No clear relationship was found among the sonographic appearances, duration of symptoms, or clinical outcome.