title: Quality of life after dislocation of hip arthroplasty: a prospective cohort study on 319 patients with femoral neck fractures with a one-year follow-up.
abstract: OBJECTIVE
  A primary arthroplasty constitutes a standard procedure in the treatment of patients with displaced fractures of the femoral neck. Although dislocation of the prosthesis remains a significant clinical problem, there are no previous reports on its influence on health-related quality of life (HRQoL). We analysed how a dislocation of the hip arthroplasty influenced the patients' HRQoL.
  
  
  METHODS
  In total 319 consecutive patients with a displaced fracture of the femoral neck treated with a primary arthroplasty were included in a prospective cohort study. We used a mixed-effects model regression analysis to evaluate factors of importance for HRQoL (EQ-5D(index) score) during the first 12 months following surgery.
  
  
  RESULTS
  A dislocation of the arthroplasty occurred in 21 of the 319 patients (7%), 8 of whom had a single dislocation and 13 recurrent dislocations. At 4 months, the EQ-5D(index) score displayed a significantly worse outcome for patients with recurrent dislocations compared to patients with no dislocation (P = 0.001), and a trend towards a worse outcome for patients with a single dislocation (P = 0.08). At 12 months, the mean EQ-5D(index) score of patients with recurrent dislocations was still substantially lower (P = 0.001), while the EQ-5D(index) score for patients with a single dislocation had returned to a level similar to that of patients with no dislocation. Our analysis of the EQ-5D dimensions indicates that the difference was mainly due to perceived difficulties in self-care and usual activities and increased problems with anxiety/depression.
  
  
  CONCLUSIONS
  A recurrent dislocation of the hip arthroplasty in the treatment of patients with femoral neck fractures seems to result in a persisting deterioration in the HRQoL, while patients with a single dislocation seem to experience only a temporary deterioration.
authors.affiliation: Karolinska Institutet, Department of Clinical Science and Education, Section for Orthopaedics, Stockholm Söder Hospital, 118 83, Stockholm, Sweden. anders.enocson@sodersjukhuset.se
authors.forename: Anders
authors.initials: A
authors.lastname: Enocson
authors.forename: Hans
authors.initials: H
authors.lastname: Pettersson
authors.forename: Sari
authors.initials: S
authors.lastname: Ponzer
authors.forename: Hans
authors.initials: H
authors.lastname: Törnkvist
authors.forename: Nils
authors.initials: N
authors.lastname: Dalén
authors.forename: Jan
authors.initials: J
authors.lastname: Tidermark
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D015331:Cohort Studies; D005260:Female; D005265:Femoral Neck Fractures / Q000601:surgery*; D005500:Follow-Up Studies; D006617:Hip Dislocation / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D011795:Surveys and Questionnaires; D013548:Sweden