The skeleton is the third most common site for metastatic involvement after the lung and liver. Prostate, breast, lung, renal and thyroid carcinomas account for 80 % of all skeletal metastasis, with the femur being the most affected site of long bones [1,2].

With improved oncological treatment, prolonged patient survival leads to an increased prevalence of metastatic osseous disease and eventually to impending or pathological fractures, as classified by Mirels et al. [3]. Once this complication occurs, it can contribute to the quality of life deterioration and possibly reduce survival [4,5].

Mirels' classification for impending long-bone pathological fractures is a scoring system used to assess the risk of pathologic bone fractures in individuals with metastatic bone diseases [3]. The classification is based on four criteria: the long bone involved, the metastatic lesion's location, matrix density, and pain. Each criterion is scored on a scale of 1–3, with higher scores indicating a higher chance of fracture. According to Mirels' classification, a score higher than seven is considered an impending fracture (≥8) [6]. Mirels classification has its limitations; while the sensitivity of Mirels classification is relatively strong (71–100 %), specificity is poor (13–50 %) [7]. This may lead to overtreatment of these patients with the related complications.

The optimal orthopedic intervention at this point should provide stability for the remainder of the patient's life with a low revision rate. Surgical options include intramedullary nailing, internal fixation with plating, and endoprosthesis [4]. Frequently resectioning the metastatic lesion or debulking requires cementation of the cavity with Polymethyl methacrylate (PMMA). Intramedullary nailing appears to be advantageous in treating pathological fractures because of its superior ability to withstand mechanical loads, reinforce the entire long bone (including the femoral head and neck), and address potential skip lesions [8]. Larger lesions may require open curettage followed by PMMA filling in addition to internal fixation [1]. An endoprosthesis is a good treatment option for a metastasis involving the femoral head, neck, or both. Arthroplasty, partial or total joint replacement, provides excellent long-lasting pain relief and improved function in patients with pathological femoral neck fractures [9,10]. Open reduction and internal fixation of pathological pertrochanteric by plating, or subtrochanteric fractures, carry a very high failure rate [11]. Despite multiple options, the best approach for treating a pertrochanteric pathological fracture (endoprosthesis vs. reconstruction nail) remains controversial [12].

Femoral fractures in the elderly are a known cause of mortality and morbidity, especially when undertaking conservative treatment. This increases the complications secondary to immobility, such as deep vein thromboembolism, pneumonia, urinary tract infections, and general deterioration [13,14]. Patients in this age group with metastatic carcinoma are comparable to their healthy peers regarding metabolic frailty and infection susceptibility [15,16].

The severe impact of metastatic femoral fractures has been studied, and upfront fracture-preventing surgery is warranted to overcome potential fracture complications [[17], [18], [19]]. Previous studies have found improved survival rates after preventive fixation of impending pathological fractures compared to acute pathological fractures [20] but evaluated diaphyseal fractures excluding femoral neck, metaphysis and diaphysis. This study was a population-based study with inherent limitations. However, prophylactic fixation also has potential downsides, such as a higher risk of deep vein thrombosis and pulmonary embolism compared to treating acute fractures [21].

Relevant advances in oncologic treatment throughout the years included genetics-targeted therapies, i.e. identification of the Epidermal Growth Factor Receptor (EGFR) mutation in non-small cell lung cancer, which has created bimodal distributions for life expectancy [[22], [23], [24]], as well as advances in overall bone health, such as the use of Denosumab, which has reduced skeletal complications [[25], [26], [27]]. Additional improvements in chemotherapy issued with targeted therapy for estrogen, progesterone and EGF receptor-positive patients with breast cancer [28,29].

This study examines whether the advances in surgical technique, oncological treatments, and an improved overall medical treatment for proximal femoral fractures in the elderly require an up-to-date evaluation of the benefit of prophylactic fixation in proximal femoral metastatic involvement over actual pathological fracture treatment and the overall mortality. The current study is important as it adds granularity and is a clinical study of patients; this adds to the literature and validates the previous population-based study derived from administrative databases.

This study reevaluates the impact of preventive surgery for impending femoral pathological fracture compared to the acute treatment of a pathological fracture on patient mortality and morbidity.