Plantar Fibromatosis (Ledderhose Disease)

Plantar fibromatosis (Ledderhose disease) is the plantar counterpart of Dupuytren disease: a benign fibroblastic proliferation of the plantar aponeurosis that shares its biology and mimics it on histology. Unlike Dupuytren, it rarely causes contracture of the toes. It produces firm, often painless nodules in the medial plantar arch that can become symptomatic with weight-bearing.

What the examiner wants. The hallmark is the very high recurrence rate after surgical excision, approaching 100% after local excision in some series. It is the single most tested point, and it is why conservative management is the cornerstone and surgery is reserved for refractory, symptomatic disease. Examiners also test the Dupuytren association and the rationale for non-operative management.

Who gets it. It is less common than Dupuytren disease, at approximately one-tenth of its prevalence. Onset peaks at 30-60 years, with a slight male predominance that is less pronounced than in Dupuytren, and like Dupuytren it predominantly affects people of Northern European descent. Between 25 and 50% of cases are bilateral.

The Dupuytren association. Dupuytren disease is the strongest risk factor, present in 10-65% of patients. A family history also counts: autosomal dominant inheritance with variable penetrance has been suggested.

Other risk factors. Diabetes mellitus carries the metabolic association seen across the fibromatoses. Chronic heavy alcohol intake is linked to both Dupuytren and Ledderhose, as is liver disease, especially alcohol-related cirrhosis. Anti-epileptic drugs, particularly barbiturates and phenytoin, are implicated, and recurrent microtrauma to the plantar fascia is debated as a trigger.

The plantar aponeurosis. The plantar fascia has three bands: medial, central and lateral. The central band is the thickest and strongest; it arises from the medial calcaneal tubercle and inserts into the forefoot through slips to each toe. Plantar fibromatosis most commonly affects the medial band, in the mid-arch, and not the central band origin that is the site of plantar fasciitis.

View larger

The lesion. Plantar fibromatosis is not a true neoplasm, but it is a clonal proliferative disorder, not a reactive one. The nodules are myofibroblasts in a collagenous matrix, and they follow the same three-stage biology as Dupuytren: proliferative, involutional and residual (see Classification).

The cells and the matrix. The myofibroblasts carry a contractile apparatus (alpha-smooth muscle actin positive) and align along lines of mechanical tension, as in Dupuytren. The matrix is dominated by type III collagen, the same as in Dupuytren disease: type III (immature) predominates in the proliferative phase, transitioning to type I (mature) in the residual phase. TGF-beta, especially beta-1 and beta-2, is the key cytokine driving fibroblast proliferation and collagen synthesis. Chromosomal abnormalities (trisomy 8, trisomy 14) have been reported in some nodules.

Why recurrence is so high. The entire plantar fascia is predisposed to fibromatosis, not just the excised nodule. This field defect means that removing one nodule does not eliminate the predisposition, and the genetic propensity to fibromatosis cannot be excised.

What surgery adds. Surgical trauma itself triggers TGF-beta release and myofibroblast activation. Excision is incomplete when microscopic disease extends beyond the palpable nodule, and weight-bearing stresses the repair, promoting fibroproliferation. This is why even total plantar fasciectomy has measurable recurrence rates.

Superficial versus deep fibromatosis. An examiner will often broaden "what is Ledderhose?" into "classify the fibromatoses". In the WHO classification of fibromatoses, plantar fibromatosis is a superficial (fascial) fibromatosis, a completely different clinical animal from the deep (desmoid) fibromatoses, and the two should not be lumped together.

The superficial family. Superficial (fascial) fibromatoses are small and slow-growing, arise from fascia or aponeurosis, do not metastasise and are only minimally locally aggressive. This family is the fibromatosis diathesis: palmar (Dupuytren), plantar (Ledderhose), penile (Peyronie) and knuckle pads (Garrod). They are managed conservatively, with surgery for symptoms.

The deep family. Deep (musculoaponeurotic) fibromatoses, the desmoid tumours or aggressive fibromatosis, arise from deep musculoaponeurotic structures and are locally infiltrative and aggressive, though still non-metastasising. They are driven by beta-catenin (CTNNB1) mutations when sporadic, or APC mutations in familial adenomatous polyposis and Gardner syndrome. Subtypes are extra-abdominal, abdominal-wall and intra-abdominal.

A different treatment pathway. Desmoid disease is managed by active surveillance, systemic therapy (for example tamoxifen or NSAIDs, tyrosine-kinase inhibitors, and the newer gamma-secretase inhibitor nirogacestat), radiotherapy, and wide resection only when needed.

Ultrasound first. Imaging is primarily by ultrasound or MRI, and ultrasound comes first. It shows a fusiform or nodular thickening of the plantar fascia, hypoechoic or isoechoic, continuous with the fascial fibres. It is quick, inexpensive, allows dynamic assessment and guides injection, but it is operator-dependent and offers limited soft-tissue characterisation of atypical lesions.

MRI second. Sequences are T1, T2, fat-suppressed T2 (STIR) and contrast-enhanced. The lesion is a nodular thickening arising from the plantar fascia, typically along the medial band, of low-to-intermediate signal on T1. T2 signal varies with stage: cellular proliferative nodules may show higher T2 signal, while mature collagenous nodules are low on both T1 and T2. MRI is the gold standard for pre-operative planning and for ruling out sarcoma, and is indicated before surgery, when sarcoma is a concern, and after failed conservative management.

Telling it from sarcoma. The features that separate plantar fibromatosis from malignancy are its origin from and continuity with the plantar fascia, homogeneous signal and enhancement, and the absence of necrosis. The reassurance is weakest in the cellular nodule: the Robbin review in the evidence section notes that its high T2 signal overlaps with other soft-tissue tumours, which is why an atypical lesion needs histology rather than reassurance.

Biopsy when atypical. The indications for biopsy:

• Rapid growth
• Large size (greater than 5 cm)
• Deep location
• Heterogeneous MRI enhancement
• Necrosis

If any atypical feature is present (rapid growth, size greater than 5 cm, necrosis, deep extension), biopsy is mandatory before any excisional surgery.

Use core needle biopsy under imaging guidance and avoid excisional biopsy as the initial diagnostic step. The aim is to exclude fibrosarcoma, malignant fibrous histiocytoma or synovial sarcoma.

Conservative first, for everyone. The vast majority of nodules are asymptomatic or minimally symptomatic and never require surgery, and the natural history is one of slow progression to a static residual phase. Non-operative management is first line for all patients because surgical recurrence rates are so high. Its goal is symptom relief and functional improvement; the disease may remain stable or even regress.

After surgery. Post-operative complications are common, and recurrence may present months to years after surgery.

Prognosis. The best outcomes come with a solitary nodule, residual phase disease, no Dupuytren diathesis and a patient willing to manage conservatively. The worst come with multiple nodules, bilateral disease, a strong Dupuytren diathesis (young onset, family history, multiple fibromatosis sites) and surgery in the proliferative phase.

Proportion. Plantar fibromatosis is a benign condition that rarely causes significant functional impairment, and treatment should be proportionate to symptoms. Aggressive surgical treatment of a minimally symptomatic nodule is inappropriate given the recurrence risk.