A tarsal coalition is an abnormal bridge of bone, cartilage, or fibrous tissue joining two tarsal bones, most often the calcaneus to the navicular or the talus. It affects around 1% of the population, becomes painful in early adolescence as the bridge ossifies, and typically presents as a stiff flat foot with recurrent ankle sprains.
A calcaneonavicular coalition usually becomes symptomatic between ages 8 and 12, a talocalcaneal coalition between 12 and 16. The child reports deep, vague pain below the ankle, worse on uneven ground and after sport, with a foot that feels 'locked'. Peroneal muscle spasm gives the older name, peroneal spastic flatfoot.
When immobilisation and orthoses fail, resection of the bar with interposition of fat or extensor digitorum brevis prevents regrowth and restores subtalar motion. Results are best when the coalition is small, the articular surfaces are preserved, and hindfoot valgus is corrected at the same sitting — often with a calcaneal lengthening — so the reconstructed foot is not left overloaded laterally.
Most children are in a splint or boot for two to four weeks after isolated resection, begin motion early to prevent scarring, and return to sport at around three months. When an osteotomy is added, protected weight-bearing extends to six weeks and full return takes four to six months.
Regrowth is uncommon when the resection is complete and the gap is filled with interposition tissue. Persistent pain after surgery more often reflects uncorrected hindfoot valgus or established arthritis than true recurrence.
Often yes. It arises from failed segmentation in the embryo and shows autosomal dominant inheritance with variable penetrance, so it is worth examining siblings who complain of foot pain.
Dr. Mutasem Aldhoon is a leading Pediatric Orthopedic Consultant specializing in complex lower extremity deformities. With extensive experience in advanced joint-sparing and reconstructive techniques, he is the trusted authority for severe pediatric flatfoot and neurological foot reconstructions.
