What is a Saddle Bone Deformity?

The top of the foot has occasionally been referred to as the "saddle" as it is thought to resemble the back of a horse where the saddle might go. There is particular deformity or lump that can develop on the top of the foot, so you see this sometimes called a Saddle Bone deformity. Technically this is known as a dorsal metatarsal cuneiform exostosis. It is an overgrowth of some bone that develops on the top of the foot at the base of the first metatarsal bone and the bone behind that. It is almost never called a saddle bone deformity in the medical literature. The bone becomes enlarged due to jamming of the joints at the base of the first metatarsal and the bone grows in response to this jamming due to the excessive movement of that metatarsal. It can appear as a hump over the top of the foot. The enlarged piece of bone can become painful due to pressure on the lump from the shoe, especially if the laces are done up tightly. This can also be a particular problem in sports like skiing or ice skating as the boots that are used are quite rigid and can place a lot of pressure on the enlarged bone. The pressure may also cause a bursitis to develop, and this can become inflamed. If there are shooting type pains associated with this then that might mean that a nerve has been impinged, otherwise the pain is usually described as a dull or sharp in its nature. There may be some redness over the area. The enlarged bone is easy to see on a x-ray. There may also be some osteoarthritis in the joints seen on x-ray that may be contributing to the symptoms. There are other conditions that can mimic a saddle bone deformity such as a ganglion cyst or a tendinitis.

The best initial management of a saddle bone deformity is simply to avoid closed in footwear as much as possible as that will mean that there is no pressure on it. Sometimes you can just simply remove the laces from the eyelets in the shoe over the area of the enlarged bone and that could be enough to get pressure off it for the symptoms to improve. Another way to get pressure off the area is to stick a pad under the tongue to the shoe over the area. These pads can be shaped like a donut with a hole in the middle or a U shape. Both of these are designed to get pressure off the painful area. Adhesive felt can be used and stuck under the tongue of the shoe. If this works well, then a more permanent material such as poron can be used and glued in place for the long term. If the saddle bone deformity is particularly swollen then a steroid injections and nonsteroidal anti-inflammatory drugs may be needed in the short term to get relief. If these measures do not work for a saddle bone deformity, there are surgical options to excise the bone and fuse the joint.

Craig Payne is a University lecturer, runner, cynic, researcher, skeptic, forum admin, woo basher, clinician, rabble-rouser, blogger and a dad.