The Truth About Plantar Fibromatosis (Fibroma) Surgery: Is It Really Necessary?

My reply to Finn about treating plantar fibromas, also known as plantar fibromatosis, is basically a blog post, so here it is.

Finn on March 7, 2018, at 12:08 pm

Comment on your comment on Missrunner’s question from 2013 ( Yes, very late). Could plantar fibroma be the same as what was described? If yes, how would that be treated?

aoeditor on March 11, 2018, at 4:43 pm

Hi Finn,

It is never too late, my man—great question to bring up a good subject for all the peeps out there in the AO nation. However, now you've gone and really made me mad. Besting the AO is not allowed, but you got me fair and square. I just read Missrunner's question, and you have a great point, and I think you are right- she is describing a plantar fibroma. So, let’s talk about plantar fibromas or plantar fibromatosis (PFb). First, don’t take my word for it. If you possibly have one, go to a podiatrist or orthopaedic foot and ankle specialist and have it looked at.

Here are the basics of plantar fibromatosis:

• Plantar fasciitis and PFb have nothing to do with each other. Nothing.

• PFb is benign. If you want to really stir a hornet’s nest and spend lots of money, go ahead and have someone biopsy it.

• PFb is diagnosed 100% of the time by a bit of history and simple exam. Period.

• MRIs have no place here. The last patient I saw who came with an MRI in hand was scheduled for surgery within a week because there was a question as to the possibility of malignancy. This person was a level 4 plus tennis player at 55 years old who did not want the interruption imposed by surgery. Especially when they found out from me that it was not needed. I talked them through it, and 8 years later, they still play tennis at a high level and have a painless lump along the medial border of the plantar fascia slightly larger than when I saw them the first time. By the way, malignant tumors are rare in the foot. Really.

• PFbs are on the medial border of the plantar fascia (see image below of fairly large PFb) and can be single or multiple in a sort of chain. They are typically painless unless someone sticks an orthotic, especially a rigid one, in the shoe or the person keeps messing with it to physically irritate it. I can say if one presses on any part of the body long enough and enough times it gets pissed off just like me. I don’t care where or what it is.

• They can have a very loose association with Type II diabetes. I said very loose, so forget it.

• They typically grow to a certain point and stop. Who knows why? Just be glad they do. I have seen a couple out of 500 plus over the years get larger than 4 cm, and most remain smaller.

• The best treatment is to (after being seen and you know it is a PFb) IGNORE it. Even if it is mildly painful.

• If the pain from contact/irritation is significant, then here is what can be done short of surgery. To be honest and to be a bummer, if you are having enough pain to seek help and even consider surgery, these mitigations don’t really work too well.

  • Reduce any arch in your shoes, and take orthotics out. Actually, that is good advice for everyone. Orthotics aren’t all that, but they are a great money maker.

  • Soft true custom orthotics with strategic relief areas to match the PFb bumps can help, but they are not too predictable

  • No cortisone injections, but Xiaflex may have some promise. I have no opinion or experience with Xiaflex type injections.

• If the pain and really any quality of life issues get to be too much, then surgical resection is the last resort. My personal stats are about 12 done out of >500 PFb seen, just to give you some perspective.

• Know that there are three fairly commonly known and too often encountered surgical complications: (This is why a good surgeon might actively steer you away from harm’s way)

     –Recurrence. The PFb can return/regrow in 25-33% of cases. Just to brag a bit, mine was far less (see margins below).

     –Neuroma formation. Nerve injury that can lead to painful amputation (of the nerve, not the foot) neuromas of the intertwined or adjacent sensory nerves. Ouch!

     –Wound dehiscence. The incision, by definition, creates a closed “pocket” that can fill with blood (hematoma and ultimately a seroma) just after surgery or not seal or takes time to bond together. This pocket produces a space or a barrier between the walls of the internal surgical site. The walls are not juxtaposed and thus can't heal. Think of applying glue to two boards to be joined that never touch each other- no dice. Then, if you walk on, it slips and slides and opens up or is a dehiscence. I had only two, and both times, the patients walked against my advice. My patients were asked to be non-weight bearing for 3 weeks, and I would advise this for any of you as well. It is a hassle, but not as much as the hassle as the extra time to wait for a wide-open wound dehiscence to heal. The good news is that the dehisced wounds heal just fine, however, it is a big detour.

If you have this surgery:

• Make sure the surgeon is skilled and has done at least a few

• The resection must be fairly radical with what we call wide margins, or recurrence will be more likely if only the main mass is excised. The microscopic satellite lesions nearby get missed, and they love to grow back

• Watch weight bearing post op as noted above. I say be extra safe here, why not? As Forest Gump said, “And that’s all I have to say about that.”

Wait, one more thing. Plantar fibromas do not respond to calf stretching.

Stay healthy, my friends,

AO