Transfibular ankle arthrodesis with rigid internal fixation: an assessment of outcome

BACKGROUND: Transfibular ankle arthrodesis with internal fixation and fibular onlay grafting has resulted in acceptable fusion rates. This study analyzed the results of ankle arthrodesis using one operative technique in a large series of patients with high and low risks for nonunions. METHODS: Fifty consecutive patients had a transfibular ankle arthrodesis with rigid internal fixation and fibular onlay strut grafting from 1997 to 2004. Two patients were lost to followup. The remaining 48 patients had preoperative and postoperative clinical and radiographic examinations and then were stratified into high-risk and low-risk groups for ankle nonunions. Fifteen of 48 patients were considered at high risk for nonunion. Rate of osseous fusion, satisfaction with the procedure, correction of the deformity, and relief of pain were evaluated. Thirty-five of 48 patients were evaluated with the AOFAS ankle-hindfoot scale at an average 45 months after surgery. RESULTS: Forty-six of 48 patients had bony union (96% union rate). Fourteen of 15 (93%) high-risk patients had bony fusion in an average of 83 days. Thirty-two of 33 patients (97%) in the low-risk group had bony fusion at an average of 81 days. The AOFAS ankle-hindfoot score improved from 38 to 74 in 12 of 15 patients in the high-risk group and from 34 to 69 in 24 of 33 patients in the low-risk group from preoperative to postoperative scores. CONCLUSIONS: A transfibular ankle arthrodesis with rigid internal fixation and fibular onlay strut grafting can achieve a high rate of union in both a low-risk and high-risk patient populations. This technique can be an effective approach for most primary and revision cases with or without significant deformity. In addition the AOFAS ankle-hindfoot score improved significantly both in the high-risk and low-risk groups.