TEN YEAR LIFE EXPECTANCY AFTER PRIMARY TOTAL HIP REPLACEMENT

Abstract

We have determined the 10 year life expectancy of 5,831 patients who had undergone 6,653 elective primary total hip replacements (THR) at a regional orthopaedic centre between April 1993 and October 2004.

Methods: We ascertained dates of deaths for all those who had undergone surgery during this period and constructed Kaplan Meier survivorship curves for these patients. Standardized mortality ratios were calculated by comparing this data with available UK mortality rates for the same age groups over the same time period.

Results: The mean age at operation was 73 with a male to female ratio of 2:3. Of those with 10 year follow up 29.5% had died a mean of 5.6 years after surgery. 10-year survivorship was 89% in patients under 65 years at surgery, 75% in patients aged between 65 – 74 years and 51% in patients over 75.

The standard mortality rates were significantly higher than expected for patients under 45 years, 20% higher for those between 45 and 64 years and progressively less than expected for patients aged 65 and over.

Discussion: By comparing our mortality curves with prosthesis survivorship curves from the most recent Swedish Arthroplasty Register results we were able to demonstrate that the survivorship of cemented hip arthroplasties exceeds that of the patients over the age of 60 in our area. As these prostheses are less expensive than their uncemented equivalents this suggests these are the prosthesis of choice in this age group.