FEMORAL NECK FRACTURES, EPIDEMIOLOGY, ANATOMICAL DESCRIPTION, MECHANISM OF ACTION, CLASSIFICATION, CLINICAL EVALUATION, IMAGING EVALUATION, TREATMENT AND COMPLICATIONS

Introduction: Femoral neck fractures (FNF) are frequent and devastating injuries in orthopedics and traumatology. It usually has several therapeutic options depending on the type of fracture and the comorbidities of the affected individual, among the conservative treatment alternatives are bed rest with or without traction and among the surgical alternatives are internal fixation. Objective: to detail the current information related to femoral neck fractures, epidemiology, anatomical description, mechanism of action, classification, clinical evaluation, imaging evaluation, treatment and complications. Methodology: a total of 40 articles were analyzed in this review, including review and original articles, as well as clinical cases, of which 31 bibliographies were used because the other articles were not relevant to this study. The sources of information were PubMed, Google Scholar and Cochrane; the terms used to search for information in Spanish, Portuguese and English were: fractures, femur, femoral neck, prosthesis, trauma. Results: 80% are generated in women, and the incidence doubles every 5 to 6 years in women over 30 years of age. It presents bimodal incidence. The risk factors are female sex, white race, advanced age, poor health, smoking, alcohol consumption, previous fractures, history of falls and low estrogen concentrations. Magnetic resonance imaging (MRI) is the test of choice for the diagnosis of undisplaced or occult fractures not observable on plain radiographs. Up to 40% of impacted or nondisplaced fractures will displace if they do not undergo internal fixation. Secondary displacement is 5% following internal fixation. Pseudarthrosis may complicate up to 5% of non-displaced fractures and up to 25% of displaced fractures; furthermore, osteonecrosis complicates up to 10% of non-displaced fractures and up to 30% of displaced fractures. Conclusions: femoral neck fractures present a high incidence, the mechanism of action mostly presented in young people is high energy trauma, in the elderly the most common mechanism is low energy falls. Patients with displaced femoral neck fractures are unable to walk and show shortening and external rotation of the lower limb. Anteroposterior projections of the pelvis are indicated, as well as anteroposterior and cross lateral projections of the affected proximal femur. The goals of treatment are to relieve the patients pain, restore hip function and have rapid mobilization through anatomical reduction and internal fixation or by prosthetic replacement. Conservative treatment of fractures is recommended in individuals at extreme surgical risk; it can also be considered in individuals with dementia, who do not maintain the ability to walk and have little symptomatology due to hip pain. Among the most important complications are pseudarthrosis and osteonecrosis. Surgery to treat nondisplaced femoral neck fractures is associated with a higher number of consolidation and associated with less avascular necrosis compared to conservative treatment. KEY WORDS: fractures, femoral neck, trauma, prosthesis.