Isolated subtalar arthrodesis.

Forty-eight isolated subtalar arthrodeses in 44 patients with an average follow-up of 59.5 months were retrospectively reviewed. Original diagnoses included talocalcaneal coalition, healed calcaneal fracture with subtalar arthrosis, acquired flatfoot because of posterior tibial tendon dysfunction, degenerative subtalar arthrosis, subtalar instability, and psoriatic arthritis. Ninety-three percent of patients were very satisfied or satisfied with their treatment. Pain and function improved significantly, and the American Orthopaedic Foot and Ankle Society ankle-hindfoot score at follow-up was 89. There were six unsatisfactory results: three feet had calcaneal fractures and three were malpositioned. Union was achieved in all cases. Transverse tarsal motion was diminished by 40%, dorsiflexion by 30%, and plantarflexion by 9%. There was a 36% and 41% incidence of mild radiographic progression of arthrosis in the ankle and transverse tarsal joint, respectively. Isolated subtalar arthrodesis provided a highly successful result in the disease presented, and this study provides support for the use of a selected hindfoot fusion procedure for specific indications.