A tarsal coalition is a bone condition that causes decreased motion or absence of motion in one or more of the joints in the foot. The lack of motion or absence of motion is due to abnormal bone, cartilage or fibrous tissue growth across a joint. When excess bone has grown across a joint, there is usually little or no motion in that joint. Cartilage or fibrous tissue growth can restrict motion of the affected joint to varying degrees, causing pain in the affected joint or in surrounding joints.

The bones found at the top of the arch, the heel, and the ankle are referred to as the tarsal bones. A tarsal coalition is an abnormal connection between two of the tarsal bones in the back of the foot or the arch. This abnormal connection between two bones is most commonly an inherited trait and passed down from generation to generation.

Symptoms usually include an aching sensation deep in the foot near the ankle or arch, accompanied by muscle spasms on the outside of the affected leg. Non-surgical treatment includes special shoes or inserts, physical therapy and anti-inflammatory medication. Consult your physician before taking any medication.

Surgery sometimes is performed to allow for more normal motion between the bones, or to fuse the affected joint or surrounding joints.