Between January 1 2006 and December 31 2013, at our department 324 patients underwent hemiarthroplasty (HA) for displaced femoral-neck fracture with a bipolar prosthesis (Variokopf, Link®, Germany) by the use of the posteriolateral approach. Patients with pathological fractures and HA performed with direct lateral approach were excluded. A retrospective cohort study were conducted. Patients with prosthetic dislocation formed one group and patients without dislocation formed the control group.