The surgical management of metastatic lesions of the femur
Keywords:bone metastasis, femur, pathological fracture
Background: Malignant tumours commonly metastasise to bone. When this occurs in the femur, surgical intervention is required to reduce pain and restore mobility post fracture, or as a prophylactic measure when fracture is anticipated. This is typically in the form of replacement with hemi- or total arthroplasty or stabilisation with an intramedullary device. The indications for one modality over the other are debatable and the reported outcomes and complications are varied. The purpose of this study is to assess the management algorithm for bony metastasis of the femur at a tertiary bone tumour unit, and the outcomes of the surgical strategies employed.
Methods: A retrospective cohort study was performed of all patients presenting to our institution with femoral metastasis, both with and without pathological fracture, who were managed surgically from April 2016 to February 2020. Fractures of the femoral neck were managed with cemented arthroplasty. All other fractures were managed with intramedullary nailing, as were all lesions requiring prophylactic stabilisation. Data was recorded regarding demographics, primary pathology, location of lesion, type of surgery, and implant used. The incidence of complications including radiological failure of fixation, infection, thromboembolic phenomena, re-operation and mortality were recorded.
Results: Eighty-five femurs in 77 patients were included (mean age 61 years, range 20–90). Lesions were located in the femoral neck (19/85, 22%), intertrochanteric (20/85, 24%), subtrochanteric (40/85, 47%), diaphyseal (2/85, 2%) and metaphyseal/per-condylar (4/85, 5%) regions of the femur. A total of 64/85 (753%) procedures were performed for fractures and 21/85 (25%) prophylactically. Eighteen of the 85 (21%) underwent long-stemmed cemented bipolar hemiarthroplasty, 1/85 (1%) long-stemmed cemented total hip replacement (THR), 62/85 (73%) cephalomedullary nailing, and 4/85 (5%) retrograde femoral intramedullary nailing. Mean follow-up was eight months (range 1–36). There were no dislocations or periprosthetic fractures in the arthroplasty group. One failure (1/66, 2%) of fixation occurred in the intramedullary nailing group. Six deaths occurred in the arthroplasty group (6/64, 9%) and 24 in the nailing group (24/66, 36%) during the study period. Four patients suffered from thromboembolic phenomena (4/77, 5%). Of the 13 patients who sustained a pathological fracture and were managed with intramedullary nailing and followed up for at least one year, all had achieved clinical and radiological union.
Femoral metastasis can be appropriately managed with intramedullary nailing, both prophylactically and in the event of fracture, with a low rate of implant failure and an expectation that healing will occur once stabilised. Intracapsular fractures can be managed with long-stemmed cemented arthroplasty with a low risk of subsequent fracture or dislocation.
Level of evidence: Level 4