Osteonecrosis of the talus: treatment by hindfoot fusion

The results were reviewed for 11 ankles (10 patients) that had been treated with various hindfoot arthrodeses because of symptomatic osteonecrosis of the talus. Follow-up averaged 6.5 years (range, 2-15 years). A functional assessment using a modified Mazur grading system was performed both before surgery and at final follow-up. Data were also collected on the duration of the procedure, intraoperative findings, and the patient's assessment of postoperative cosmesis (excellent, good, fair, or poor). Radiographs were analyzed to determine the interval from the procedure until bony union. Nine of the 11 arthrodeses (82%) fused with the primary procedure and achieved excellent Mazur ratings (mean, 86 points; range, 81-90 points). The average interval until radiographic fusion was 7 months (range, 4-13 months). All eight patients (nine fusions) with successful fusions graded their cosmetic outcomes as excellent or good. The average length of the procedure was 148 minutes (range, 130-300 minutes), compared with an average of 92 minutes (range, 62-151 minutes) for ankle arthrodeses performed by the same surgeons in rheumatoid or osteoarthritic ankles (P < 0.001) and 102 minutes (range, 75-164 minutes) from a report in the literature. Two of the procedures were complicated by nonunions secondary to infections. In one patient, after treatment by debridement and intravenous antibiotics, reinfection and chronic osteomyelitis developed with a subsequent below-knee amputation. The other patient was treated successfully with debridement, antibiotics, and subsequent revision arthrodesis, which fused solidly at 9 months with an excellent result. We conclude that hindfoot arthrodeses for osteonecrosis can be technically demanding, but, despite having a long time to bony union, they can have an excellent clinical outcome.