Tarsal coalition is a fusion or sticking together of the tarsal bones in the foot. The tarsals are 7 bones located at the back of the foot. It is a congenital disease meaning you are born with it. Midfoot pain may appear in adolescents with this condition, but symptoms may not show until later in some people.
Symptoms of Tarsal coalition include:
- Pain in the midfoot area in adolescents, usually after hard training or activity
- Collapsed foot arch
- Reduced ankle mobility
- Walking with a limp
- Stiffness in the foot and ankle
Symptoms usually do not appear until the bones start to mature, between the ages of 10 and 16. However, some people do not display any symptoms until later on in life. Sometimes they only find out following a sprained ankle which fails to heal. Tarsal coalition sometimes causes tarsal tunnel syndrome and the patient never knew they had it.
An X-ray may show up an osseous coalition and an MRI may show up a fibrous one.
What causes tarsal coalition?
The bones involved are the Calcaneus, Talus, Navicular, Cuboid, and the three Cuneiform bones. The most common joints affected are the calcaneonavicular joint between the Calcaneus and the Navicular, and the talocalcaneal joint between the Talus and the Calcaneus.
It usually affects adolescents as the fibrous or cartilaginous joints between the bones ossify (turn to bone) and harden. This causes a decreased range of motion in the rearfoot causing strain on the ankle joint. Tarsal coalition can occasionally develop in later life due to an infection or arthritis in the joints, or an ankle injury.
After diagnosis, your doctor places your foot in a cast or walking boot to allow proper rest. Initially the aim is to reduce pain and inflammation.
They may perform biomechanical analysis to identify and correct foot problems such as overpronation. This is where your foot rolls in or flattens too much. Specialist insoles called orthotics correct this.
When pain allows, perform exercises to improve foot and ankle mobility.
Corticosteroid injections are sometimes also recommended.
If conservative treatment fails your doctor may recommen surgery for tarsal coalition. Surgery involves either removing excess bone growth, or completely fusing the two joints together.