Bone Transport In Chronic Infected Non-Union Using AO External Fixator

Abstract

We used AO external fixator for bone transport in 4 patients with chronic osteomyelitis after trauma including 2 cases with femoral shaft fracture (type I and III A), one femoral supracondylar fracture (type III B) and one case with fracture of the proximal of tibia (plateau) type III B. The mean age of the patients was 34.7 years (24-46 years). All fractures were open because of car accident. Internal fixation had been initially carried out for the patients with femoral fracture and calcaneal pin traction for the patient with plateau fracture. The mean time between fracture and the onset of bone transport external fixation was 85 days (24-180 days). All the patients were culture-positive, identified the gram negative bacteria including Pseudomona, E-coli and Enterobacter as the causative pathogens. The mean of bone defects was 10.2 centimeters (7-14 centimeters).The mean duration of bone transport was 134 days (77-210 days). The total duration of treatment from placing AO external fixator until bringing out the device was 11-25 months (mean, 19.2 months). According to our experience when bone transport carried out by AO external fixator and with use of a five-toseven day latency period and a rate of distraction of one millimeter per day, approximately 1.9 month treatment (including time for distraction and healing) was required per each centimeter bone defect which is less than the duration of treatment using Ilizarov technique for bone transport requiring 2 to 3 months treatment per centimeter. In our experience major intercalary defects in femur and also tibia have been bridged and new bone has formed in the defect with concomitant restoration of the osseous integrity and alignment of the limb.