Treatment of malunion and nonunion at the site of an ankle fusion with the Ilizarov apparatus. Surgical technique.

BACKGROUND Malunion and nonunion of an ankle fusion site are associated with pain, osteomyelitis, limblength discrepancy, and deformity. The Ilizarov reconstruction has been used to treat these challenging problems. METHODS We reviewed the results in twenty-one ankles that had undergone a revision of a failed fusion, with simultaneous treatment of coexisting pathologic conditions, with use of the Ilizarov technique. Eight patients had undergone ankle fusion only, eleven had undergone ankle and subtalar fusion, and two had undergone pantalar fusion. Eighteen patients with an average limb-length discrepancy of 4 cm underwent limb lengthening simultaneously with the revision surgery. The average patient age was forty years. Indications for treatment were malunion (eleven patients), aseptic nonunion (eight patients), and infected nonunion (two patients). Clinical, subjective, objective, gait, and radiographic analyses were performed after an average duration of follow-up of 83.4 months. RESULTS Solid union was achieved in all ankles. The functional result was excellent for fifteen patients, good for three, fair for two, and poor for one. The bone result was excellent for ten ankles, good for nine, fair for one, and poor for one. All eighteen patients who underwent gait analysis had a heel-to-toe progression gait, and twelve achieved normal walking velocity with their shoes on. A plantigrade foot was achieved in each case, and only two patients had >5 degrees of residual deformity. During the Ilizarov treatment, forty-one minor complications (treated conservatively) and twenty major complications (treated surgically) occurred. After removal of the circular frame, seven other complications, which required four additional operations, occurred. CONCLUSIONS In patients with a failed ankle fusion, infection, limb-length discrepancy, and foot deformity can be addressed simultaneously with use of the Ilizarov apparatus to achieve a solid union and a plantigrade foot, usually with a clinically satisfactory result.