Subtalar fusion for isolated subtalar disorders. Preliminary report.

Retrospective observations on subtalar fusions performed for isolated subtalar disorders in 11 feet were performed to determine whether a satisfactory result could be obtained without significant changes to the talonavicular and calcaneocuboid joints. Preoperative diagnoses included five feet with degenerative arthritis secondary to a calcaneal fracture, four feet with a talocalcaneal bar, one foot with a degenerative subtalar arthropathy of unknown cause, and one foot with an unstable subtalar joint secondary to a peroneal tendon rupture. The average follow-up period was 41.5 months (range, 23-103 months). The hindfoot was fused in a average of 6 degrees of valgus. The feet maintained approximately 50% of their transverse tarsal motion, compared with the contralateral side. No foot developed hypermobility of any tarsal joint. Three feet fused for degenerative joint disease developed very mild talar beaking, and two feet fused for a tarsal coalition developed a mild progression or increase in talar beaking. Three feet demonstrated very minimal osteophyte formation at the calcaneocuboid joint. Functional and pain ratings for patients who had fusions for talocalcaneal bars or degenerative joint disease were good to excellent. Minimal radiographic changes at the talonavicular and calcaneocuboid joints secondary to increased stress brought about by the fusion did not seem to be clinically significant. Isolated subtalar fusion for lesions limited to the subtalar joint, which includes talocalcaneal bars, is a satisfactory method of treatment.