plantar fibromaIf you have found a lump in your arch, more than likely you have developed a plantar fibroma. A plantar fibroma (also known as plantar fibromatosis) is a benign growth or nodule, really a thickening, of the plantar fascia – a thick ligament in the bottom of your foot. If you have found a bump or lump in your arch, make an appointment to see us in our Seattle foot and ankle clinic. 

Video: How to Treat Plantar Fibromas

Cause of Plantar Fibromas

No one is quite sure of the cause of plantar fibomas, but there is evidence that trauma to the plantar fascia may cause them to form. The most common type of trauma is simply over-stretching of the plantar fascia due to the arch flattening too much. When the arch flattens, the foot gets longer and this stretches the fascia. In some people this excessive stretching can lead to formation of fibromas.

Are Plantar Fibromas Painful?

The fibroma itself doesn’t cause pain, but pressure on the lump can lead to pain in the arch when walking or standing.

Diagnosis of Arch Lumps

We can usually diagnose the lumps in your arch by examining your foot. If further information is required we can visualize the mass using diagnostic ultrasound in our office.

Treatment of Plantar Fibromas

Custom Orthotics for Fibromas and Other Lumps in the Arch

Custom orthotics are the most effective treatment for plantar fibromas. Orthotics must accomplish two things to best treat this problem:

  1. Decrease tension on the plantar fascia
  2. Decrease pressure on the lump in your arch

In order to effectively reduce both tension and pressure, orthotics for fibromas must:

  1. Conform very close to the arch of the foot (figure 2). Most orthotics we see made for fibromas do not conform close enougth (figure 3).
    orthotics for fibromas

    Fig 1: Close fitting orthotic

  2. Incorporate an indentation for the fibroma. This indentation should be very deep to best reduce pressure. Most orthotics we see for this problem either do not include an indentation or the indentation is too shallow.
  3. Be as wide as the entire foot in order to transfer pressure off of the fibromas. Most of the orthotics we see for this issue are simply too narrow.

Fig 2: Orthotic gaps from arch

It’s critical that the orthotics act to maximally reduce tension and pressure on the fibromas in order to provide the best outcome so let’s go over this in more detail.

To decrease tension, we prescribe an orthotic that hugs your arch very close – this is called a total contact orthotic. By aggressively supporting your arch, we prevent the foot from flattening and decrease tension on the plantar fascia. By decreasing tension on the fascia you decrease tension on the fibroma.

We have to be very careful, however, because an orthotic that hugs your arch very close could irritate the plantar fibroma. To prevent this, we have an indentation or pocket added to the orthotic exactly in the location of the fibroma. This acts to distribute pressure off of the lump. But to be effective this indentation must be both deeper and wider than the fibroma itself. Too often orthotics for plantar fibromatosis simply do not have the indentation(s) or the indentation is much too shallow.

If made correctly orthotics are extremely effective at reducing the pain of plantar fibromas. If you have had orthotics made that have not been effective get a second opinion from a podiatrist who specializes in orthotic therapy.

We are experts in providing orthotics that are both extremely effective and comfortable. Make an appointment today to see us in our Seattle clinic

Injections for Plantar Fibroma

Injection of the fibroma can be help shrink the fibroma in some patients. It doesn’t work all of the time, but many patients find this is the most effective way to make the lump smaller. Injection should always be done in conjunction with orthotics to help reduce pressure and tension on the fibroma.

Other Treatments for Fibromas

  • Surgery: Surgical removal has also not been found to be very effective. The surgery itself has some significant side effects including flattening of the arch due to weakening of the plantar fascia. In addition, there is an extremely high likelihood of recurrence of the fibroma. We do not recommend surgery except in cases where nothing else has helped and there is significant pain.
  • Topical Medication: There is one topical prescription cream that has been shown in a single study to help reduce plantar fibromas. We think that more study is needed to determine it’s true effectiveness, but we can discuss this with you at your appointment.