Retrospective analysis of the rate and interval to union for joint arthrodesis of the foot and ankle.

Arthrodesis is a common procedure indicated for surgical treatment of end-stage degenerative joint disease of the foot and ankle. Many published studies have reviewed the union rate, focusing on specific technique or fixation. However, studies reporting on the average period required to achieve fusion, irrespective of the type of fixation or surgical method used, have been lacking. We report on the union rate and interval to fusion in patients who had undergone primary arthrodesis of various joints of the foot and ankle. A retrospective review of the medical records of 135 patients was performed. The specific joints studied were ankle, and the subtalar, triple, first tarsometatarsal, first metatarsophalangeal, and hallux interphalangeal joints. Our results showed that the average interval for complete fusion was significantly less for the joints in the forefoot, with the subtalar joint, ankle, and triple arthrodesis requiring a longer period to achieve complete fusion. The nonunion rate was also greater when the fusion involved the joints of the rearfoot. Our results have refuted the idea that 6 weeks is the minimum period required to achieve fusion in the foot and ankle. The results of our study support the need for additional education of the patients and surgeons that the interval required for recovery after foot and ankle fusion depends on the location and surface area that has been fused.