A Long Femoral Stem Is Not Always Required in Hip Arthroplasty for Patients With Proximal Femur Metastases

Background During hip arthroplasties for treating proximal femur metastases, a long femoral stem frequently is used, presumably protecting the entire femur against progression of the existing lesions or development of new lesions. However, it is unclear whether a long stem is really required.

Questions/purposes We therefore determined in patients with proximal femur metastases (1) the reoperation rate related to different stem lengths after hip arthroplasty, (2) the risk of tumor progression in the same femur (the progression of preexisting lesions and the development of new distal femur lesions), and (3) complications.

Methods We retrospectively reviewed 203 patients (206 femurs) with proximal femur metastases treated with hip arthroplasty. These femurs were divided into three groups based on femoral stem length: short stem (SS), 12 to 14 cm; medium stem (MS), 20 to 24 cm; and long stem (LS), 25 to 35 cm. We reviewed reoperations, disease progression in the same femur, and complications. Minimum followup was 2 days (median, 487 days; range, 2-4853 days), with most patients followed to their death.

Results Only three femurs were revised owing to tumor progression, with no difference among the SS, MS, and LS groups. Two SS prostheses were revised for nononcologic reasons. Tumor progression in the same femur was uncommon during the patient’s survival, with 11 femurs showing progression of the proximal lesion and five femurs showing new distal lesions. The complication rate was higher in the LS group (28%) than the combined rate in the MS and SS groups (16%), especially acute cardiopulmonary complications (18% versus 7.5%).

Conclusions Reoperation after hip arthroplasty for proximal femur metastases is uncommon and not correlated with femoral stem length. Considering the high complication rate associated with a LS hip prosthesis, we do not believe its routine use is justified.

Level of Evidence Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.