Acute shortening versus bone transport for the treatment of infected femur non-unions with bone defects

Abstract

Background: The bone transport technique has been a well-known method in the treatment of osteomyelitis of the long bones with large segmental bone defects. However, one of the major drawbacks with this traditional technique is the long-lasting consolidation period, which may entail infectious and non-infectious complications. To overcome this drawback, several techniques were developed, one of which is acute shortening and re-lengthening. The aims of this study were: 1) to present our experience with a new modified technique of acute shortening and re-lengthening using a monolateral external fixator combined with a retrograde intramedullary nail, and 2) to compare its results with the classic Ilizarov bone transport method in the management of infected non-unions of the distal femur with bone loss.

Methods: This retrospective study compared these two techniques. 17 patients were treated using our modified technique of acute shortening and re-lengthening (Group A); 15 patients were treated using segmental bone transport (Group B). The average follow-up was 66 months (range: 24-180) in Group A and 70 months (range: 24-240) in Group B. The mean bone loss was 5.5 cm (range: 3-10) in Group A and 5.9 cm (range: 3-10) in Group B. The primary outcome of the present study was to compare the external fixator time (EFT) and external fixation index (EFI) between the two groups. The bone and functional status were also assessed.

Results: The mean EFI was lower in Group A (mean: 31.8 days/cm; range: 24-50) than in Group B (mean 48.7 days/cm; range: 40-100) (p = 0.02). The mean EFT was shorter in Group A (mean: 120 days; range: 100-150) than in Group B (mean: 290 days; range: 100-400) (p = 0.0003). With respect to the bone and functional results, no difference was observed.

Conclusions: Although both techniques could be employed safely in the treatment of infected non-union of the distal femur with size defects ranging between 3 cm and 10 cm, our modified technique of acute shortening and re-lengthening may confer greater patient satisfaction because of shorter EFI.

Keywords: Acute shortening; Bone defect; Bone transport; Infected non-unions of the femur.