Point-Counterpoint: Is Conservative Care The Best Approach For Plantar Fibromatosis?
This author says conservative treatment can reduce the symptomatology and shrink the plantar fibroma whereas wide excision surgery has a high recurrence rate and increased potential for wound healing issues and nerve entrapment.
By Michael S. Downey, DPM, FACFAS
Plantar fibromatosis is a benign, locally invasive soft tissue tumor characterized by fibroblast proliferation within the plantar fascia. The vast majority of plantar fibromas are asymptomatic and require no treatment other than to reassure the patient as to the benign nature of the affliction.
When clinicians encounter a plantar fibroma that they cannot diagnose clinically, a magnetic resonance image (MRI) or musculoskeletal ultrasound can confirm the soft tissue character of the nodular mass as homogenous and collagenous in nature. Only atypical masses or those that remain suspicious after diagnostic imaging studies necessitate biopsy. Treatment beyond biopsy is only indicated if the plantar fibromatosis is symptomatic, locally invasive or prominent in shoes or with weightbearing.
When treatment is necessary, one should use conservative treatment initially for the significant preponderance of plantar fibromatoses. Conservative treatment can be divided into biomechanical and pharmacological measures. Pharmacological treatment can be further subdivided into topical, oral and injectable medications. Although much of the conservative treatment lacks direct supporting evidence-based medicine and studies to support its efficacy, many of the modalities available have some evidence to support their use.
Non-surgical treatment typically begins with modalities aimed at offloading the plantar fibromatosis.
One can construct a simple, removable donut pad for an isolated or smaller plantar fibroma. For larger lesions, over-the-counter insoles or custom-molded orthotics may be needed to decrease hyperpronation and the tension on the plantar fascia, potentially decreasing the symptoms associated with the plantar fibromatosis.1
Assessing The Impact Of Topical And Injectable Medications
Although there are many pharmacological options for the conservative management of plantar fibromatosis, it is important that the treating physician understand their indications, contraindications, intended effect and dosage. Currently, topical and injectable medications merit the greatest consideration for the management of the symptomatic and/or enlarged plantar fibromatosis.
Recently, much attention has been given to the transdermal topical delivery of verapamil. Verapamil belongs to a class of drugs known as calcium channel blockers. Research has shown calcium channel blockers, in both in vivo and in vitro studies, to inhibit fibroblasts and the synthesis and secretion of extracellular matrix macromolecules, including the components of fibrous tissue disorders, collagen, glycosaminoglycans and fibronectin.
There have been no reported studies on the effectiveness of topical transdermal verapamil or intralesional verapamil injections for plantar fibromatosis. However, logically, it would appear the use of topical transdermal verapamil gel and intralesional verapamil injections may have some effectiveness in the management of plantar fibromas. Since the primary effect of the medication is to inhibit fibroblast activity, the effectiveness would likely be greatest in the proliferative or involutional (active) phases of the fibromas’ development and less helpful in chronic fibromatosis that has entered the residual (end) phase.
Recently, the use of topical transdermal 15% gel (150 mg verapamil per cc of gel) has been promoted and become popular. The recommended dosage is 1.0 cc of the gel twice daily to the skin directly over the plantar fibromatosis for six to 12 months.1 I have effectively used this protocol of topical verapamil to decrease the symptomatology associated with plantar fibromatoses and to soften the nodular mass volume. To date, I have not seen topical transdermal verapamil gel completely resolve a plantar fibroma.