plantar fibromatosis

So…. you are reading this discussion because you have this lump on the bottom of your foot and you are obviously concerned. Fact is you may have more than one lump; there may actually be a cluster of lumps.

This condition is known as plantar fibromatosis (not to be confused with plantar fasciitis)and in the vast, vast majority of cases these are benign growths that occur on the bottom of the foot. Incidentally, a similar condition occurs on the palms of the hands known as Dupuytren’s contracture.

Plantar fibromatosis is a disorder of unknown origin. It is basically a herniation of the plantar fasciathrough its outer covering known as the aponeurosis. Some speculate that it is the result of tiny tears in the plantar fascia, which then undergo rapid repair, and actually over repair the area. This leads to thickened nodules ranging in size from .5cm to 3.0cm in diameter. They can then invade the dermis of the skin and sometimes the flexor tendons on the bottom of the foot making them appear even larger. These nodules may lay dormant for years only to rapidly increase in size in a very short period of time.

Note the nodular lesion in the picture below.

Typically, patients will present to the office more out of concern about the lump rather than pain, but these growths can be painful. If the nodules are not painful the treatment of choice is to leave them alone. Sometimes an MRI may be helpful in an effort to show the true extent of the fibroma and whether or not it is pressing on adjacent tissue.

If, however, there is pain conservative management is indicated. Conservative care involves orthopedic padding around the area via padding in the shoe to keep pressure off the area. An orthotic can be very helpful in two ways. One is to keep the plantarfascial ligament from overstretching, which is considered by some to be an aggravating factor, plus the orthotic can be built in a certain manner to keep pressure off the lesion.

Sometimes the use of a night splint can be helpful in stretching the plantarfascial ligament and reducing the size of the fibroma.

I have injected these nodules with cortisone, which in many cases shrinks them somewhat or at the very least eliminates the pain. But, I will tell you that they can be painful injections.

There is also available on the market a topical medication that can be applied. The histology behind plantar fibromatosis is hyper-fibroblastic activity. Fibroblasts, which are the building blocks of collagen formation, are working in overload in the case of plantar fibromatosis. It has been shown that Verapamil (a drug used in hypertension as a calcium channel blocker) can be effective when applied topically to the nodule. This medication is made by a group of compounding pharmacists in Texas. It has to be applied daily and over the course of a few months the nodules are supposed to shrink in size. I have to say that I have not had any personal experience with the medication but I do know it is quite expensive as I inquired on behalf of a couple of patients.

I have read studies that suggest the success rate (reduction of pain and size of the growth) can be over 70 percent. It may take as long as six months of twice a day application to achieve these results.

If conservative measures fail and if these nodules are very painful, your only other option is surgical removal. This is not a straightforward procedure as there are many potential complications.

Experience has shown us that more than the nodule itself has to be removed. Just removing the nodule alone results in a high incidence of recurrence; I have read as high as 57%. So in order to avoid recurrence, sections of healthy plantarfascial ligament on both sides of the nodule have to also be removed. This then creates the problem of not having use of the plantarfascial ligament whose purpose is to maintain the arch of the foot similar to the way a bowstring works on a bow and arrow. Secondly, the incision obviously has to be made on the bottom of the foot and it is generally a long curvy type incision, which opens the risk of scar formation in the incision when healed. The patient may no longer have the fibroma but they may end up with a painful scar that hurts just as much to walk.