Bunions: Overview

Bunions: Overview

A bunion is a common condition of the foot that impacts patients from all walks of life. By definition, a bunion is poor alignment of the big toe that happens over time. The medical term for a bunion is hallux valgus, where hallux means big toe, and valgus describes how the toe is angled.

Who can get a bunion? Anyone can develop this problem, but females tend to get bunions more than males do, and since bunions usually develop over time, they are seen more in older patients than younger ones. There are several factors that would put someone at risk for developing a bunion. Besides age and gender, wearing high heels, or actually, any shoe with a narrow toe box, can squeeze the toes together, pushing the bones out of alignment. People who have loose ligaments to begin with are also at risk, as is someone with flat feet.

To really understand what a bunion is, knowing the bones involved is important. Let us take a look at this right foot from an inside view. Here is the big toe, and here is the pinky toe. These first two bones, called phalanges, make up the part of the big toe that you can wiggle. This bone called a metatarsal, is the bone that connects the phalanges to the midportion of the foot.

Let us dive a little deeper into why a bunion looks the way that it does. This is a top down view of a right foot. On the left is a foot with normal alignment of the toes. On the right is a foot with a bunion. In the normal foot, the angle between the metatarsal and phalanges is really small, almost a straight line. But, in the foot with the bunion, the angle is much more pronounced. Not only is there a large angle at this joint, there is also a larger angle at this joint, making the alignment look even worse.

Patients usually want to know how a bunion forms. It is a result of any combination of the risk factors previously mentioned, but the first thing to happen is the soft tissue on the inside of this joint starts to stretch out and get weak. As a result, the big toe shifts in and a bump can be seen on the inside of the foot. The tendons that move the big toe are now also out of alignment and keep the toe from straightening back out.

When a patient goes to the doctor's office to have their foot looked at, the health care provider will ask several questions that can give them a good idea if a bunion is the problem. They will move the joints of the big toe to see how loose they are, and if it is possible to straighten them back out. X-rays will give the doctor all the info they need to confirm that a bunion is causing the deformity. They can measure the angle of the two bones, called the hallux valgus angle, to determine how severe the deformity is.

This chart gives a generic grading scale based on how big the angle is. CT scans for a bunion are not common and are not required to make an accurate diagnosis. Over the years, health care providers have used many different ways to treat bunions, so choosing the right treatment for each individual patient is important to get the foot back in the right alignment.