Evaluation of complications associated with bifocal bone transport as treatment for either proximal, intermediate or distal femoral defects caused by infection: outcome analysis of 76 patients.

Background: The purpose of this study was to evaluate the outcomes of bifocal bone transport in the treatment of femoral bone defects caused by infections.

Methods: Clinical and radiographic data of patients with infected femoral nonunion treated by the bifocal bone transport at our hospital were analyzed retrospectively, from January 2008 to December 2019. Depending on the location of bone defects, the patients were divided into three groups (proximal, intermediate, and distal). The Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria was applied to assess the bone and functional outcomes. Postoperative complications of three groups were documented and compared.

Results: Seventy-six cases of infected femoral bone defects (31 cases of proximal, 19 cases of intermediate, and 26 cases of distal) were managed by bifocal bone transport successfully with a mean follow-up time of 30.8 months (range, 23 to 41 months). There were 58 men (76.3%) and 18 women (23.6%), with a mean age of 38.8 years (range, 23 to 60 years). The bone union was received in 76 cases with a mean of 6.9 months (range, 5 to 8 months). Pin tract infection was observed in twenty-nine cases (38.1%), 7 cases (9.2%) of muscle contractures, 3 cases (7.9%) of joint stiffness, 13 cases (17.1%) of axial deviation, 2 cases (2.6%) of delayed union, one case (1.3%) of nonunion, and none (0%) of transport gap re-fracture. One patient (1.3%) was scheduled for knee arthroplasty when bone transport treatment ended.

Conclusions: Bone transport using an external rail fixator was a practical method to treat the femoral bone defects, since the satisfactory rate of bone union and limb function recovery. Complications of distal femoral bone transport were more severe than the proximal and intermedia, but the rate of complication was the least of the three groups. Soft-tissue-related complications were more likely to occur in the intermediate bone transport.