strange curvature/bump on top of foot

by Angela
(Houston, TX)

I had a lapidus bunionectomy 4 months ago. The last xray I had (2 months ago) was "normal" and indicated proper healing. However, I've recently noticed a huge, hard, bump on the top of my foot when viewed from the side. From what I've been able to find on the internet, my foot appears to have an increased meary's angle w/ bony prominence mainly over cuneiform area. It's almost as if my metatarsals have taken on a curved/arched position. I am planning to go to podiatrist, but I'm terrified I will have to have surgery re-done. Could this strange bump be something benign?

RESPONSE

Hi Angela,

I would expect your condition to be benign in the area of 99.9% keeping in mind there is always a possibility of something out of the ordinary being present.
You do not mention the onset of any pain. That is a good thing. Two possibilities come to mind.
The first would be a failure of the fusion at the tarsal-metatarsal joint which in theory would create a large Meary's angle. However, if the fusion did not "hold" I would figure there would be pain involved because of the motion that would be now occurring at the level of that joint, every time you walk.
Since you describe the bump as huge I will assume this bump is not the type of bumps that we see in the actual incision line itself which indicates an inclusion cyst. This is an inflammation, generally from a deep suture. In these cases, there is a small lump which also is painful on direct pressure. So, we have ruled that out.
For me, with no way to actually see your foot, the most likely explanation is displaced hardware that was put into the foot to hold the fusion. Sometimes screws start to back out or metal plates will dislodge and all of a sudden the patient will have a protrusion where none existed the day before.
Your surgeon will be able to identify that immediately. If that is the case, then the decision has to be made about what to do with it. Depending on how well fused the joint is, he or she may elect to remove the hardware as it will only cause problems going forward. If the fusion of the joint is not totally resolved, the surgeon may choose to put everything back together, or might even just consider putting you on crutches, so the fusion can finish healing. Again, I am just guessing here because I cannot examine you.
There is also the possibility that the "bump" is a soft tissue swelling, of the tendon that runs over the bone is this area. It may have been irritated from the hardware in the surgical site.
Just to finish the thought, one other problem that occurs after bone surgery is an overgrowth of new bone, where bone has previously been removed. The problem here is that this overgrowth generally takes more than four months to occur, usually well over a year, so I am not sure this is a consideration in your case.
The right thing to do is to see your surgeon and let he or she figure out whats going on.

Marc Mitnick DPM
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