Postoperative Ambulatory Performance Status Significantly Affects Implant Failure Rate Among Surgical Treatment Strategies in Patients With Proximal Femur Metastasis.

Abstract

Surgical treatment strategies for proximal femur metastasis have been reported with mixed results. Little is known about risk factor for implant failure except for longer patient survival. Therefore, we determined whether implant survivorship differed among treatment strategies, as well as risk factors for implant failure. We retrospectively reviewed a consecutive 106 patients with proximal femur metastasis treated with prosthesis replacement (n=38), intramedullary nail (n=32), and dynamic hip screw (DHS) (n=36). Eastern Cooperative Oncology Group (ECOG) scale and Karnofsky index were used to evaluate functional outcome. Patient characteristics and postoperative ambulatory performance status were assessed for their values in determining implant failure. Overall implant failure rate was 11.3% (12 of 106). Prosthesis replacement was related to better implant survivorship (P=0.041), without mechanical failures. On the contrary, 7 of the 10 implant failures in the fixation group were considered mechanical failures. Better postoperative ambulatory status (ECOG≤2) was a risk factor for implant failure (P=0.03). Notably, for patients with poor ambulatory status (ECOG≥3), implant survivorship was not different among choice of implants. In conclusion, prosthesis replacement would be a more durable option in the treatment of proximal femur metastasis. Postoperative ambulatory status could be an additional consideration. For patients with poor expected ambulatory performance status, fixation with intramedullary nail or DHS might be considered for a less technical demanding procedure.