Of 103 subtalar extra-articular arthrodeses followed for over five years, 58 per cent were rated satisfactory. The main cause of unsatisfactory results was over-correction at the time of surgery, converting the hind part of the foot from a valgus to a varus position. During the past five years, the incidence of postoperative varus deformity has been reduced drastically by establishing proper position of the talus and calcaneus by roentgenograms made in the operating room. Since the study showed that the Grice procedure, properly performed, is durable, it seems safe to predict that further follow-up of the procedures done in the last five years will reveal a much higher incidence of satisfactory results.
Valgus deformity of the ankle joint is common in a lower extremity severely paralyzed by poliomyelitis. since this makes correction by subtalar arthrodesis more complex, the plane of the ankle joint must be determined roentgenographically prior to fusing the subtalar joint.