[Long-term development of tibio-astragalus arthrodesis]. / Evolution à long terme des arthrodèses tibio-astragaliennes.

ABSTRACT

Twenty-eight arthrodeses of the ankle have been reviewed with a mean follow-up of nine-and-a-half years. The arthrodeses were all carried out using the same technique of osteotomy of the lateral malleolus and fixation with a Charnley compression device. The main indication for fusion was post-traumatic arthritis. The number of complications, most of them benign, was not negligible and amounted to 42 per cent, including superficial infections, skin necroses and lesions of the posterior tibial nerve. Revision operations were needed in 17.5 per cent of cases during the year after operation, most of them for malposition. The clinical results were satisfactory in three-quarters of the cases and poor in one-quarter. Radiological changes in the joints distal to the fusion were relatively marked in the subtaloid joint and slightly less in the midtarsal joint. Theses changes are a source of concern for the future because of their pre-arthritic appearance and their progressive nature. Adaptive hypermobility of the midtarsal joint was seen in only one-third of the cases. The changes were greater when the hindfoot was in equinus, a position which was often aimed for in this series. The author advises internal fixation with screws and discusses the future potential for arthroplasty.