• OBJECTIVES
    • Instability after total hip arthroplasty is a troublesome complication. It commonly occurs in the first 3 postoperative months, but the risk continues over time. There are numerous treatment options, but they have relatively unpredictable outcomes. Numerous factors have been associated with dislocation, but research has mainly focused on the surgical ones. Epidemiological factors remain the subject of much debate. We aimed to establish the incidence of dislocation over time.
  • METHODS
    • The Scottish National arthroplasty non-voluntary registry is based on SMR01 records (Scottish Morbidity Record) data. We analyzed the Scottish National Arthroplasty Project to find patients' dislocation rates.
  • RESULTS
    • There were 62,175 total hip arthroplasties performed from April 1989 to March 2004 with an annual incidence of dislocation of 0.9%. We found no increase in the rate of dislocation after 2 years.
  • CONCLUSIONS
    • It appears there is no late increase in dislocation rate.
  • LEVEL OF EVIDENCE
    • Prognostic study, level II-1 (prospective study).