Management of resistant distal femur non-unions with allograft strut and autografts combined with osteosynthesis in a series of 22 patients

Abstract

Introduction and purpose: Challenges to the surgeon in managing cases of resistant non-union of the distal femur include poor bone stock, disuse osteopenia and joint contractures. Procedures varying from simple bone grafting to megaprosthesis revision have been described. We successfully managed such cases using our technique of combining cortical allograft struts to augment the defect in the femoral condyle coupled with autogenous iliac crest bone grafting and locking plate osteosynthesis.

Materials and methods: Between April 2012 and May 2014, 22 patients who presented with resistant nonunions of the distal femur following initial surgery were managed using this technique. Cortical allograft struts were taken from the tissue bank of our institution. All patients were followed up post operatively and their time to union was noted. Functional outcome was calculated using LEFS (Lower extremity functional score). The average follow up of all our patients was 24 months.

Results: All patients went on to achieve complete bony union. The average union time was 6.2 months (5 to 8 months). One patient who was a diabetic had superficial infection post operatively which was treated successfully with IV antibiotics. Average knee flexion was 110 degrees (80 to 130 degrees). The mean LEFS score was 72 (59 to 79).

Conclusion: Combing a locking plate fixation with the bone grafting technique of using an allograft strut to support the metaphyseal medial bone defect and autografts gives a good union and a good functional outcome in the management of resistant non-unions of the distal femur by enhancing the biology and providing a good structural support to the distal femur.

Keywords: Allograft strut; Autografts; Distal femur fractures; Resistant non-union.