QUALITY OF LIFE AFTER DISLOCATION OF HIP ARTHROPLASTY IN PATIENTS WITH FRACTURES OF THE FEMORAL NECK – A PROSPECTIVE COHORT STUDY ON 319 CONSECUTIVE PATIENTS

Abstract

Introduction: Hemiarthroplasty (HA) and total hip replacement (THR) are standard surgical procedures in the treatment of elderly patients with displaced fractures of the femoral neck with a predictable outcome regarding hip function and health-related quality of life (HRQoL). However, dislocation of the prosthesis remains a significant problem in this patient cohort with a reported incidence of 2–16% after HA and 2–22% after THR. Even though a dislocation is a relatively common, severe, and expensive complication, there are no previous prospective studies reporting the HRQoL for patients suffering prosthetic dislocations.

Patients and Methods: During the year 2003, 2213 consecutive patients with an acute hip fracture admitted to any of the four major university hospitals in Stockholm County were included in a prospective cohort study. From that cohort, 319 consecutive patients with a displaced femoral neck fracture (Garden III and IV) treated with a primary HA or THR were included. Patients with severe cognitive dysfunction and/or dementia were not included. HRQoL was assessed with the EQ-5D. The EQ-5D index score during the last week before the fracture and at 4 and 12 months after surgery was calculated. All dislocations and associated reoperations were recorded. Patients were divided into three groups: no dislocation (0), only one dislocation (1), and those suffering recurrent dislocations (≥2) during the 12-month follow-up. We used a mixed linear model to perform a multivariable analysis of the influence of dislocations on HRQoL measured as the EQ-5D index score over time. Six independent factors were analyzed: dislocation, time, type of prosthesis (THR, cemented HA, and uncemented HA), ASA class, gender, and age.

Results: A prosthetic dislocation occurred in 21 of the 319 patients (6.6%). All first and second dislocations occurred before the 4-month follow-up. Patients suffering recurrent dislocations had a significantly lower EQ-5D index score compared to those without dislocations at both 4 and 12 months. Patients suffering only one dislocation had a temporary decrease in the EQ-5D index score at 4 months while their EQ-5D index score at 12 months was equal to that of patients without dislocations. The adjusted multivariable analysis indicated that dislocation, type of prosthesis and time were significantly related to the quality of life.

Discussion: In patients with fractures of the femoral neck treated with a primary hip arthroplasty recurrent dislocations of the prosthesis had a pronounced negative influence on the patients’ HRQoL, while in patients with only one dislocation, the HRQoL seems to recover during the first year after surgery.