The Center for Podiatric Care and Sports Medicine

Bumpy Ride: Saddle Bone Deformity

Posted by on Wednesday, August 1st, 2012

Sure, you may think you know everything about bumps on your foot because you read about ganglion cysts, those squishy lumps that can grow on the top of your foot. How about this, though–what if that bump on the top of your foot is hard and bony?

Okay, you got me–what if that bump on the top of my foot is hard and boney? Then you, my friend, most likely have a saddle bone deformity. Or as we fancy anatomical types call it, a “metatarsal cuneiform exostosis.”

I like the first name better. I thought you would, but the official name helps us understand where this is all happening. The metatarsals are the long bones of the foot that connect to our toes. The metatarsal cuneiform joints are the three joints at the base of the metatarsals at midfoot. An exostosis is a bony growth. So we’re talking about a bony growth at midfoot, right about at the bottom of a metatarsal bone.

Where does the saddle bone part come in? If your foot was a horse and you wanted to put a saddle on it so a tiny elf could ride your foot on a mystical night lit by a crazy full moon, you’d put the saddle right about where your metatarsal cuneiform joint is located. At least that’s my story. It’s more like the saddle bone deformity  is at the peak of the arch of your foot, “saddling it.”

So why would I have a bony growth there? A saddle bone deformity can occur for a number of reasons. People with high arches may be prone to them. Poor foot mechanics can cause the bone to grow. An injury in the area may lead to a saddle bone deformity. If the metatarsal cuneiform joint moves around too much, bone may grow in order to stop the excess movement.

Is it bad, other than being weird and ugly? No, a saddle bone deformity isn’t a serious condition. It just causes problems when you put a shoe on and have to deal with a bump. They may also press down on the peroneal nerve, which will add pain.

How do I know I have a saddle bone deformity? Well, you’ll see a bump on the top of your midfoot that feels hard and bony if you touch it. It probably won’t hurt if you don’t have shoes on or wear open shoes like flip flops. If you do have full cover shoes on or sandals with straps that come across midfoot, you’ll feel pain and irritation on the lump.

You can find out whether your saddle bone deformity is pressing on your peroneal nerve by testing for a Tinel’s sign. Just tap the bump with your thumb and index finger; if you feel tingling, then the saddle bone deformity is pressing on your nerve.

Of course it’s always best to see a podiatrist at The Center for Podiatric Care and Sports Medicine (212.996.1900) to get a full diagnosis and make sure the bump isn’t anything else.

So what do I do about this deformity? In most cases, a podiatrist  would recommend conservative treatment: choose shoes that don’t rub or irritate the bump, put padding into shoes that would be a problem. If the problem is poor foot mechanics, a podiatrist may recommend physical therapy to help correct your gait problem.

If, however, the saddle bone deformity is causing you a great deal of pain, a podiatrist may recommend surgery to remove the bony outgrowth. This is a relatively simple procedure that usually takes no more than an hour, and you’ll be able to put weight on that foot immediately, unlike most foot surgeries. Of course you won’t be instantly healed–it will take about four to six weeks for you to return to your full level of activity.

All in all, that’s not so bad, though. No one likes to have a deformity of any kind, let alone something that sounds like it should be associated with horses and stables more than feet. However, it’s likely that you’ll be fine, whether you choose to have the outgrowth removed or just want to live with it.

If you have any foot problems or pain, contact The Center for Podiatric Care and Sports MedicineDr. Josef J. GeldwertDr. Katherine Lai, and Dr. Ryan Minara have helped thousands of people get back on their feet. Unfortunately, we cannot give diagnoses or treatment advice online. Please make an appointment to see us if you live in the NY metropolitan area or seek out a podiatrist in your area.