DISTAL FEMUR AS A DONOR SITE OF AUTOGENOUS CANCELLOUS BONE-GRAFT

We performed a prospective clinical study and a cadaveric study to evaluate the morbidity associated with harvesting cancellous bone from the distal femoral metaphysis for use in the lower extremity. Thirty patients underwent harvest of distal femoral cancellous bone: 13 for acute trauma and 17 for reconstructive procedures. The distal femoral condyle is approached through a 6-cm midlateral, longitudinal incision. A small cortical window is created, bone graft is harvested, and the cortical window is replaced. All patients were kept nonweight bearing on the extremity for a minimum of 6 weeks. Patients were followed for an average of 10 months (range 3-32 months) and no patient was lost to follow-up before allowing full weight bearing. There were no donor site wound or neurovascular problems and no femur fractures. A cadaveric study was also performed in which bone was harvested from the distal femur, the bone was quantified, and the knees were tested in compression (axial loading). The bone-harvested knees failed in the same load range as the contralateral control knees did. The distal femoral metaphysis has many advantages compared with the iliac crest in cases when cancellous bone is needed for the lower extremity. Harvesting distal femoral bone is associated with little morbidity if performed correctly, and if the patient remains nonweight bearing for 6 weeks.