by Boyd W. Haynes III, MD
The human body, while amazing in structure and function, is prone to getting little lumps, cysts and other small, usually benign growths, especially as we age. As an orthopaedist, I see patients every day who have these, which we treat conservatively and they eventually resolve. One of these musculoskeletal “lumps” that develops in the foot is called a plantar fibroma.
No one is exactly sure what causes plantar fibromas, but it is believed there is a genetic component to their formation. It was once thought that a puncture wound or running on hard pavement caused them, but those theories are now discounted. They can develop in one or both feet and seem to occur in men and women with equal frequency. They usually develop in the age ranges of 20-70 years of age.
Plantar fibromas occur in the arch area of the foot on the plantar fascia, the thick connective tissue that wraps from our ankle, behind and under our heel and to the base of the toes. They are slow growing lesions and even though noticeable, most are asymptomatic. They may look like peas or marbles under the skin, but some can be as big as golf ball. They usually don’t hurt unless hit or stepped on, but in some cases, become painful and troublesome. They will not go away unless surgically removed.
Diagnosis involves an examination of your foot to look for the lump that is causing the pain. I will ask you questions about the lump, how long you have had it, what causes it to hurt, etc. X-rays are usually done to rule out other causes for a lump, such as an infection, bone spur, tumor or cyst, because tendons cannot be visualized on x-ray. MRI is not usually needed to diagnose this problem.
I can inject a steroid medication into the fibroma to help reduce inflammation and its size. I can also order orthotics for you, which can be put into your shoes to help relieve the pressure on the fibroma. I can also recommend Physical Therapy for you to help strengthen the foot and keep it flexible.
If the fibroma doesn’t shrink and the pain is not relieved after trying conservative measures, we will discuss surgery. Fibromas are removed during a short, outpatient procedure, which is usually very effective at relieving the pain.
Recurrence after surgery can occur. This tends to be the case in people who have multiple fibromas. Complications can include wound infection, flat-footedness and the possible development of hammertoes down the road. Permanent nerve damage is a small risk, causing a patient to have pain in the operated site, although anatomically, the surgery was a success.
Recovery requires keeping the operated foot elevated, using ice to control swelling and allowing the site to heal. You will need to wear a loose fitting shoe for about a month and restrict weight-bearing activities for 1-2 months. Crutches will be given to you to use. Return to work is in one to two weeks for a sedentary job where you can keep the foot elevated, longer for more active, labor intensive jobs.
Plantar fibromas can arise out of nowhere and can cause pain and disability. Thankfully, we can easily treat them so that you can get back to the activities you enjoy quickly.