A tarsal coalition is where there is a soft tissue or bony bridge across a joint that prevents the joint from moving and thereby the foot. The foot assumes a flat position that is not reducible i.e. it cannot be moved to the correct position. Tarsal coalitions occur in utero where the cells that form the coalition fail to separate. There are several different types of coalitions which become apparent at varying stages of development, generally between the ages of three to sixteen. Symptoms include aching within the feet which is increased following sporting activities. Coalitions can silent for many years and may only become a problem following an injury to the foot i.e. stepping off a kerb badly or spraining the ankle.
X-ray of the ankle showing coalition and arthritis of the subtalar joint
Managing Your Condition
Management of the condition is dependent on the type and the amount of arthritic changes that have developed at adjacent joints.
Conservative management includes:
• Immobilisation to help reduce the pain
• Insoles to control the movement of the foot
• Activity modification
• Steroid injections
Surgical management includes
• Isolated resection of the coalition
• Resection of the coalition with realignment of the heel bone
• Resection of the coalition with fusion of the arthritic joints