Treatment of distal femoral nonunions by external fixation with simultaneous length and alignment correction.

The use of external fixation for management of distal femoral nonunions may minimise some of the problems frequently encountered in these patients. Fifteen patients treated by external fixation for distal femoral nonunions between 1987 and 1997 were reviewed. There were nine males and six females. The average age was 35.4 years (17-53) with an average follow up of 4.6 years (2-8). Nine followed an open fracture, five a closed fracture and one a femoral osteotomy. Five of the cases were infected nonunions. In all cases an internal fixation device was used as the initial method of treatment. All patients had the nonunion site stabilised with an external fixator. In 12 cases the knee joint was crossed with the fixator to further stabilise the fracture site. All patients had some degree of leg length discrepancy or malalignment that required correction. Fourteen cases united. The other patient united following intramedullary nailing. The average time to union was 10.4 months (4-24). The average range of movement was 80 degrees after treatment. Up to 9 cm of lengthening was achieved using the external fixation system (mean 5.0 cm). The mean angular correction was 15 degrees. One patient had persistent pain despite union at the time of the last follow up. The advantages of preservation of soft tissue, immobilisation of the fracture site by crossing the knee joint and the facility for proximal lengthening make external fixation a definite option in the management of distal femoral nonunions.