Subtalar arthrodesis for subtalar arthritis.

Primary subtalar arthritis is not common except in cases of generalized arthritis such as rheumatoid arthritis. The majority of subtalar arthritis results from intraarticular calcaneal fractures. Arthrodesis seems to be the only way to solve this problem. Thirteen patients (15 feet) were treated with subtalar arthrodesis at KMCH. Preoperative diagnosis included 13 feet with traumatic arthritis secondary to a calcaneal fracture, one foot with rheumatoid arthritis and one foot with primary osteoarthritis. The mean follow up period was 24.9 months. Lateral approach without fibular osteotomy was done with decompression if there was entrapment syndrome and the arthrodesis were accomplished with use of staples for internal fixation. Eleven (85%) of the patients were satisfied with the results. Objectively, the results were excellent after 11 arthrodesis (73%), good or fair after three (20%), and poor after one (7%). There was no nonunion. Complications occurred in 1 patient who developed superficial wound infection, and in 1 patient with staple loosening. Though there was no case of nonunion, the fusion time was rather long. This might have been due to the fixation method because staples can not provide compression force which accelerates union. We believe subtalar arthrodesis is appropriate for isolated subtalar arthritis unless there are associated talonavicular or calcaneocuboid arthritis in which case triple arthrodesis will be more appropriate.