An analysis of 2 fusion methods for the treatment of osteomyelitis following fractures about the ankle.

Abstract

In the setting of chronic osteomyelitis following fractures about the ankle, reconstruction through bony arthrodesis may be used as a reconstructive alternative to amputation. During these cases, surgeons often avoid using internal fixation in an attempt to avoid reinfection or premature hardware failure. In this retrospective review, we analyzed the outcomes of chronic osteomyelitic patients who had an arthrodesis of the ankle using either internal or external fixation, focusing on salvage rates, infection clearance, union rates, and functional outcomes. No device was implanted into a known active infection. We performed a retrospective chart review of adult patients undergoing arthrodesis in the setting of a previously septic ankle following a traumatic injury. In each case, multiple irrigation and debridement procedures and local and systemic antibiotics were used. Infection status was determined by clinical exam, MRI, nuclear medicine studies, and ultimately bone biopsies. No fixation device was implanted in ankles with known active infections. Patients were divided into 2 cohorts: those fused with internal devices and those fused with external fixators. Thirty patients underwent a total of 32 arthrodesis procedures. Mean follow up time was 27 months (range, 6 to 144). Nineteen fusions were performed using internal fixation; only 2 required amputations, therefore limb salvage was 90%. Fifteen were able to ambulate with or without the assistance of an orthosis (79%). Four patients experienced recurrent infection (21%) and 5 developed nonunion (26%). Of the 13 fusions performed with external fixators, only 1 required an amputation, putting limb salvage at 92%. Ten patients were able to walk with or without the assistance of an orthosis as their final functional status (77%). Two patients experienced recurrent infection (15%), and 4 went on to nonunion (31%). When analyzing these 2 fusion methods in posttraumatic patients with previously septic ankles, with the numbers available both methods achieved similar rates of limb salvage and final functional status in these patients, as well as similar rates of infection clearance and bony union. As internal fixation is often less labor-intensive for the surgeon and more palatable for the patient postoperatively, we encourage surgeons to consider arthrodesis with internal fixation once the infection is successfully eradicated, especially in a noncompliant patient population. Level III, retrospective comparative series.