Causes / typical injury mechanism: Plantar fibromatosis, also known as Ledderhose disease, is characterized by a benign overgrowth of fascia on the sole of the foot.

Classic history and presentation:

• Patients will present with progressively growing nodules / lumps on the sole of their foot, more frequently localized to the medial band of the plantar fascia in the arch of the foot, although nodules can occur anywhere over the sole of the foot.
• The condition occurs bilaterally in approximately 25% of patients.
• Nodules are painless at first but become symptomatic as they enlarge. Pain is most commonly felt with pressure during walking or standing.
• The lumps are often swollen and tender due to pressure on the nodules.

Prevalence: Plantar fibromatosis is fairly common in middle-aged and elderly patients.

• Age – Middle-aged to elderly individuals.
• Sex / gender – Disproportionately affects men.

Risk factors: Patients are more likely to develop this disease if they have suffered repeated trauma or injuries to their foot or have long-term alcohol consumption, chronic liver disease, diabetes, or epilepsy. Additionally, patients with plantar fibromatosis are more likely to develop Dupuytren contracture, a similar disease affecting the hands.

Pathophysiology: The exact cause of plantar fibromatosis is unknown; however, it has been linked to a hyperproliferation of the aponeurosis of the foot. Some have considered a decrease in collagen and increase in fibroblasts to be the cause. An alternative theory is that there is a defect in the wound repair system leading to an overgrowth of the plantar fascia. Further research is needed to determine the exact cause. Some medications have rarely been associated with the development of plantar fibromatosis.

Grade / classification system: Plantar fibromatosis occurs in 3 phases: the proliferative phase, active phase, and resting phase –

• The proliferative phase has increased fibroblast activity and cell growth.
• The active phase is when the nodules form.
• The resting phase has decreased fibroblast activity and contracture / scar formation.