TIBIOCALCANEAL ARTHRODESIS FOR NONBRACEABLE NEUROPATHIC ANKLE DEFORMITY

Seven patients with nonbraceable, neuropathic ankle joints have been successfully treated by tibiocalcaneal arthrodesis utilizing an adolescent condylar blade plate, large cannulated AO screws, and a special cancellous allograft mixture. All patients had fragmentation and partial resorption of the talus. This procedure was considered as an alternative to below-knee amputation. Goals were limb salvage and limited community ambulation. Criteria for proceeding with the fusion were a commitment by the patient to 6 to 8 months of nonweightbearing ambulation, a biopsy and culture of the talus revealing no evidence of infection, and a nonbraceable deformity of the foot and ankle that would otherwise require amputation. A toe-level Doppler index or a transcutaneous oxygen index of greater than 0.45 was required. All patients were treated initially in a total contact cast or bivalved total contact ankle-foot orthosis (AFO) until wounds and swelling were controlled and there was no erythema. Presence of an ulcer did not preclude surgery. The arthrodesis used a combination of 7.0-mm AO cannulated screws and an adolescent condylar blade plate. A special preparation of fresh-frozen, irradiated, cancellous allograft mixed with tobramycin and vancomycin powder was used. All ankles fused solidly in an average of 5.2 months. No infectious complications were encountered. Two patients developed a stress fracture of the tibia at the proximal aspect of the blade plate before use of a bivalved AFO. These healed with nonoperative treatment in 6 weeks. All patients were satisfied with their result at their latest follow-up (average 26.9 months). They were all ambulatory in a lined, bivalved, molded AFO without the use of an ancillary device. With strong patient commitment, stringent preoperative criteria, and meticulous surgical technique, tibiocalcaneal arthrodesis can be achieved with this technique and should be added to the orthopaedist's armamentarium of nonbraceable neuropathic ankle procedures.