Development of Distal Femoral Metastasis is Rare in Cases of Isolated Proximal Femoral Metastases.

Introduction: In the setting of pathologic fractures or impending fractures of the femur, intramedullary nailing or hemiarthroplasty are the common surgical procedures indicated. Traditional teaching has stressed the importance of protecting the entire femur, and thus, it is common for these fractures to be treated with long nails or stems. Recent literature has begun to investigate whether this school of thought is valid and may challenge the perceived need for protection of the entire femur. The purpose of our study was to determine the incidence of ipsilateral distal femoral metastases after the treatment of proximal femoral metastases.

Methods: A retrospective chart review was performed that identified 66 patients who presented with completed or impending pathologic fractures of the proximal femur who then underwent either intramedullary nailing or hemiarthroplasty for surgical stabilization. Plain radiographs, in conjunction with CT, MRI, or positron emission tomography-CT when available, were used to determine whether there was disease progression and/or distal metastasis in the femur.

Results: There was one patient (1.5%) in this series who developed distal femoral metastasis after hemiarthroplasty from metastatic breast carcinoma. There were three patients (4.54%) with local progression of the disease. No patient required further intervention, and there were no cases of hardware failure or periprosthetic fracture after prophylactic fixation.

Discussion: Our findings show that there is an extremely low likelihood of developing distal femoral metastases when isolated proximal femoral metastases are present and thus protecting the entire femur may not be necessary in this clinical scenario.

Level Of Evidence: IV, therapeutic study.