Femoral neck fractures: Key points to consider for fixation or replacement a narrative review of recent literature.

INTRODUCTION: Femoral neck fractures (FNF) are frequent injuries and not rarely complicated by non-union, implant failure, and avascular necrosis. Some of these fractures represent a dilemma for trauma surgeons. Which fracture should be fixed? Which replaced with a prosthesis? How? The aim of this narrative review is to investigate the literature in order to provide the most updated and evidence-based knowledge about FNF' treatment.

MATERIALS AND METHODS: A literature research has been performed to find the essential key points to consider when dealing with FNF and their treatment. The most representative papers and the new meta-analysis were matched with authors' experience to give a concise but comprehensive view of the problem. Timing, age, comorbidities, vascularization of the femoral head, displacement, instability, comminution of the fracture, bone quality, and surgeon experience seem to be the major topics to consider in the decision making. We then focus on the optimal fixation or replacement as suggested by the literature.

RESULTS: Age is the main independent factor to consider. Timing seems essential in the elderly population to reduce mortality and important in the younger patients to reduce complications. Vascular supply should be always considered. Displacement, instability, and comminution of the fracture are negative prognostic factors for fixation as well as, theoretically, bone quality. In the elderly hip replacement is mostly indicated. A stable and solid fixation is mandatory to allow early mobilization. Sliding Hip Screws (SHS) seem preferable to cannulated screws for displaced/unstable (Pauwels II-III, posterior comminution) and basicervical fracture patterns or in smokers. There is a tendency toward Total Hip Arthroplasty (THA) also in the elderly if the patient is an indipendent ambulator without severe comorbidities. Dual mobility cups are gaining popularity in THA for FNF.

CONCLUSIONS: FNF are frequent injuries and represent, in some cases, a dilemma for the trauma surgeon. Age, timing, comorbidities, bone quality, femoral head vascularization, fracture displacement, intrinsic instability, and comminution as surgeon experience should be carefully evaluated before surgery. A case-to-case analysis of the patient-related factors helps the surgeon to make the right choice and reduce the well-known complications.