Intramedullary nailing has sufficient durability for metastatic femoral fractures

Takaaki Tanaka, Jungo Imanishi, Chris Charoenlap, Peter F. M. Choong

Surgical treatment options of femoral metastases include intramedullary nailing (IMN) and endoprosthetic reconstruction (EPR). Previous studies have demonstrated functional and oncological advantages of EPR over IMN. The purpose of this study was to (1) report the durability of IMN and (2) establish the indication of IMN for femoral metastases. In 2003-2013, among 186 surgically treated femoral metastasis cases, we retrospectively reviewed 80 consecutive IMN cases in 75 patients, including 14 pathological and 66 impending fractures. For the decision of surgical procedure (IMN, EPR, or plating), the following factors are considered: (1) fracture pattern (impending or pathological fracture), (2) Mirels' score (≥8 or <8), (3) fracture site (femoral head, neck, intertrochanter, subtrochanter, diaphysis, or distal), (4) number of metastases (solitary or multiple), and (5) patient's estimated prognosis. Patient demographics, postoperative survival, implant survival, and early postoperative mortality were reviewed. The patients were 37 males and 38 females, with a mean age of 60.1 (20-84) years. Average follow-up period was 11.4 (1-77) months. The most common fracture site was the subtrochanter (46/80), followed by the diaphysis (26/80) and the intertrochanter (8/80). The most common primary tumor was lung cancer (24/80, 32 %), followed by breast cancer (24 %) and melanoma (15 %). With the exception of six cases, all patients underwent postoperative radiotherapy to the affected whole femur. The postoperative patient survival was 14.2 and 8.4 % at 2 and 3 years from surgery, respectively, while the implant survival rate remained 94.0 % at both 2 and 3 years. Three out of 46 subtrochanteric cases required revision surgeries because of proximal breakage of implant 4-50 months after initial surgery for femoral metastases, but all were replaced by mega-prosthesis and did not need further operation until their death. Early postoperative fatal complications were observed in three patients, all of which were pulmonary dysfunction. The performance of IMN in this study was satisfactory although a large portion of sub- and intertrochanter metastases were included. Broader indication including these parts should be considered, for IMN has advantages such as lower cost and less invasiveness and even an implant failure can be revised by mega-prosthetic reconstruction.