Aims. The aim of this study was to investigate the potentially increased risk of dislocation in patients with neurological disease who sustain a femoral neck fracture, as it is unclear whether they should undergo total hip arthroplasty (THA) or hemiarthroplasty (HA). A secondary aim was to investgate whether dual-mobility components confer a reduced risk of dislocation in these patients. Methods. We undertook a longitudinal cohort study linking the Swedish Hip Arthroplasty Register with the National Patient Register, including patients with a neurological disease presenting with a femoral neck fracture and treated with HA, a conventional THA (cTHA) with femoral head size of ≤ 32 mm, or a dual-mobility component THA (DMC-THA) between 2005 and 2014. The dislocation rate at one- and three-year revision, reoperation, and mortality rates were recorded. Cox multivariate regression models were fitted to calculate adjusted hazard ratios (HRs). Results. A total of 9,638 patients with a neurological disease who also underwent unilateral arthroplasty for a femoral neck fracture were included in the study. The one-year dislocation rate was 3.7% after HA, 8.8% after cTHA < 32 mm), 5.9% after cTHA (= 32 mm), and 2.7% after DMC-THA. A higher risk of dislocation was associated with cTHA (< 32 mm) compared with HA (HR 1.90 (95% confidence interval (CI) 1.26 to 2.86); p = 0.002). There was no difference in the risk of dislocation with DMC-THA (HR 0.68 (95% CI 0.26 to 1.84); p = 0.451) or cTHA (= 32 mm) (HR 1.54 (95% CI 0.94 to 2.51); p = 0.083). There were no differences in the rate of reoperation and revision-free survival between the different types of prosthesis and sizes of femoral head. Conclusion. Patients with a neurological disease who sustain a femoral neck fracture have similar rates of dislocation after undergoing HA or DMC-THA. Most patients with a neurological disease are not eligible for THA and should thus undergo HA, whereas those eligible for THA could benefit from a DMC-THA. Cite this article: Bone Joint J 2022;104-B(1):134–141

Fractures of the proximal femur are one of the greatest challenges facing the medical community, constituting a heavy socioeconomic burden worldwide. Controversy exists regarding the optimal treatment for independent patients with displaced intracapsular fractures of the proximal femur. The recognised alternatives are hemiarthroplasty and total hip replacement. At present there is no established standard of care, with both types of arthroplasty being used in many centres. The principal advantages of total hip replacement are a functional benefit over hemiarthroplasty and a reduced risk of revision surgery. The principal criticism is the increased risk of dislocation. We believe that an alternative acetabular component may reduce the risk of dislocation but still provide the functional benefit of total hip replacement in these patients. We therefore propose to investigate the dislocation risk of a dual-mobility acetabular component compared with standard polyethylene component in total hip replacement for independent patients with displaced intracapsular fractures of the proximal femur within the framework of the larger WHiTE (Warwick Hip Trauma Evaluation) Comprehensive Cohort Study. Cite this article: Bone Joint Res 2013;2:210–13