RECONSTRUCTION OF SEGMENTAL BONE DEFECTS DUE TO CHRONIC OSTEOMYELITIS USING AN EXTERNAL FIXATOR AND AN INTRAMEDULLARY NAIL

Abstract

Callus distraction over an intramedullary nail is a rarely used technique for the reconstruction of intercalary defects of the femur and tibia after radical debridement of chronic osteomyelitic foci.

The aim of this study was to summarize our experience of distraction osteogenesis with an external fixator combined with an intramedullary nail for the treatment of bone defects and limb shortening produced as a result of radical debridement of chronic osteomyelitis.

Sixteen patients aged 16 to 63 years underwent radical debridement to treat nonunion associated with chronic osteomyelitis of 8 tibias and 8 femurs. The lesions were staged as Cierny and Mader type IVA (10) and IVB (6). The resulting segmental defects and any limb length discrepancy were then reconstructed by distraction osteogenesis over an intramedullary nail. A monolateral frame was used for the femur, and a ring type external fixator for the tibia. Two patients required local gastrocnemius flaps. Free non-vascularised fibula grafts were added to the regenerate for augmentation of a femoral defect at the time of external fixator removal and locking of the nail. At the latest follow-up, functional and radiographic results were evaluated using the Paley’s criteria.

In the femur, the mean defect was 10 centimeters (range 6 to 13 centimeters), while in the tibia it was 8.4 centimeters (range 5 to 11 centimeters). The mean external fixator index was 13.5 days per centimeter, the consolidation index was 36 days per centimeter and the mean time to union at the docking site was 9 (range 5–16) months. The average follow-up was 31.3 months. We obtained 81.25% (13 of 16) excellent results in terms of both bone and functional assessment. There were two recurrences of infection necessitating nail removal. These patients underwent revision with an Ilizarov fixator. Subsequently, infection was controlled and the non-unions healed.

This combined method may prove to be an improvement on the classic techniques for the treatment of long bone nonunions associated with chronic osteomyelitis, in terms of external fixation period and consolidation index. These appears to be no increase in the risk of complications, and the earlier removal of the external fixator is associated with patient comfort, decreases the complication rate and facilitates convenient and quick rehabilitation.