The influence of the CT scan in the evaluation and treatment of nondisplaced femoral neck fractures in the elderly.

Background: The management of nondisplaced femoral neck fractures (FNFs) has evolved, with emphasis in radiographic features such as posterior displacement. However, the role of advanced imaging in this scenario is still not well defined. Therefore, our objective is to assess the impact of a computed tomography scan (CT) on interobserver agreement (IA) of fracture classification, posterior tilt measurement, and treatment decisions in nondisplaced FNF in elderly patients. Methods: Eleven patients with a nondisplaced (Garden 1-2) FNF were assessed by six hip surgeons. On a first stage, fracture classification, posterior tilt, and treatment plan (fixation/arthroplasty) were determined only with clinical information and X-rays. On a second stage, a CT was added. The kappa coefficient (kappa) and intraclass correlation coefficient (ICC) were used to determine IA. Results: IA for Garden classification was only slight in X-rays and with the addition of a CT, with a kappa = 0.13 (0-0.28) and 0.18 (0.03-0.33), respectively. Conversely, posterior tilt measurement agreement was excellent in both schemes, with an ICC = 0.92 (0.83-0.98) and 0.92 (0.82-0.98). The IA for the proposed treatment was slight with X-rays (kappa = 0.44; 0.29-0.6), but moderate with the addition of a CT scan (kappa = 0.67; 0.52-0.82). Changes in surgical decision where made in 14 of 66 evaluations with an OR = 1.4 (0.62-3.2) for choosing an arthroplasty if a CT was used. Conclusion: IA for fracture classification and posterior tilt evaluation in nondisplaced FNF was not altered by the usage of a CT. There is improvement in treatment agreement when a CT scan is added to conventional imaging, with changes in treatment in 21% of cases.