Surgery for proximal femur metastases: endoprosthesis reconstruction or intramedullary nailing?

Abstract

Background: The proximal femur is the most common site of skeletal metastases in the appendicular skeleton. Pain relief and early mobilization are the goals of surgery for such lesions. Intramedullary nail and endoprosthesis (EP) are the commonly used implants to stabilize proximal femur metastatic lesions. There are no guided protocols determining the use of one implant over the other. Methods: A retrospective review was performed on the prospectively collected institutional database of 117 patients who underwent surgery for proximal femur metastases between January 2012 and December 2017. For the analyses, patients with the following conditions were excluded from the study: (I) metastases of the femoral head or neck without trochanteric extension, which is not an indication for intramedullary fixation (n=18); (II) previous surgery to the ipsilateral femur (n=8); (III) surgeries other than intramedullary nailing (IMN) or EP reconstruction (n=7); and (IV) concomitant metastases in the contralateral or ipsilateral femur warranting surgery (n=6). Of the remaining 78 patients, 8 patients with <3 months of follow-up postoperatively were excluded, leaving 70 patients for the analyses. The following factors were compared between the patients undergoing IMN and those undergoing EP reconstruction: incidence of postoperative complications, overall survival, local recurrence-free survival, implant survival, Musculoskeletal Tumor Society scores at 6 months and 1 year following surgery, maximum ambulatory ability of the patient following surgery, and time taken to ambulate independently without support. Results: Apart from local recurrence, 24.3% (9 of 37) of patients in the intramedullary nail group and 15.1% (5 of 33) of patients in the EP group developed complications at the operative site (P=0.658). The intramedullary nail group showed significantly higher local recurrence rate than the EP group (29.7% vs. 9.1%, P=0.030). On Kaplan-Meier analysis, the intramedullary nail group had significantly lower local recurrence-free survival than the EP group (P=0.002). There was no statistically significant difference in the maximum ambulatory ability between the two groups (P=0.082). On Kaplan-Meier analysis, the implant survival at 2 years postoperatively was significantly better in the endoprosthesis group (83%) compared to that in the intramedullary nail group (54%) (log rank, P=0.030). Conclusions: The local recurrence-free survival and implant survival are better with endoprosthetic reconstruction over intramedullary devices for proximal femoral metastatic lesions. As the complication rates and functional outcome of patients with both implants are comparable, endoprosthetic reconstruction can be safely used to provide better durability even in patients with a shorter life span to obtain the best quality of life. 11