Objective: Evaluate the treatment of C3 distal femur fractures with limited internal fixation and tensioned wire circular external fixation.
Design: Prospective cohort study, from June 1992 to July 1996.
Setting: Urban Level I trauma center.
Patients: Sixteen fractures in sixteen patients: nine male, seven female. Fractures: C3.1 one, C3.2 one, C3.3 fourteen. Twelve fractures were open: one GI, seven GII, two GIIIA, one GIIIB, and one GIIIC.
Intervention: Fractures were treated with limited open fixation of the condylar joint surface and tensioned wire circular external fixation of the metaphysis and shaft for axial alignment. Three fractures had acute autologous bone grafts.
Main outcome measurements: The patient's extremity function was evaluated by the authors by using the Sanders et al. Distal Femur Functional Evaluation.
Results: Sixteen of sixteen fractures healed. Two patients had delayed bone grafting for delayed union. Average frame time was twenty-five weeks. Average range of motion was 0 to 92 degrees. Five patients had less than 90 degrees of flexion. Five patients required a quadricepsplasty. Average follow-up was thirty-five months. One patient developed a pintract infection. One patient developed septic arthritis, and another developed osteomyelitis. The average Sanders et al. Function knee score was twenty-eight, with a maximum possible score of forty.
Conclusions: C3 fractures of the distal femur are associated with severe soft tissue injuries and bone loss. Loss of function appears to be directly related to these factors. Treatment with limited internal fixation and tensioned wire external fixation has equivalent results to other methods but has a higher incidence of infection and complications. Joint motion is retarded by binding of the soft tissues with fixation wires and pins. The technique is recommended only for salvage of severely comminuted and open fractures of the distal femur with extensive soft tissue injury. Distal femur fractures with moderate comminution and soft tissue injury should be treated with alternate methods.