CHANGE IN THE AGE DISTRIBUTION OF PATIENTS UNDERGOING PRIMARY HIP AND KNEE REPLACEMENTS OVER 13 YEARS – AN INCREASE IN THE NUMBER OF YOUNGER MEN HAVING HIP SURGERY.

Abstract

Introduction: Analysis of the ages at the time of surgery of all patients undergoing primary hip and knee replacement in a UK District General Hospital setting over a period of 13 years

Method: Retrospective study of all cases of primary hip and knee replacements performed at our institution between 1993 and 2005.

Results: A total of 4703 patients had primary total joint replacement in this period. This includes 2591 hip replacements and 2112 knee replacements. The ratio of females to males was 2:1

The average age of primary hip replacement patient was 70 years. (male patients 68 years and 71 years in females.) Over the 13 year period, the average age of male patients was noted to decline steadily from 71 in 1993 to 66 in 2003. But the average age of female patients remained constant at around 71 years.

The number of patients below age 60 years undergoing hip replacement procedures was analysed. Only 8% of patients were under 60 years of age in 1993 rising to 23% in 2005. Between 2000 and 2005 this figure was at or above 20%.

Surface hip replacement was started at our hospital in 1999. The number of patients treated with surface hip replacement as a proportion of all primary hip procedures has increased to 32% in 2005. The average age of these patients was 57 years. The sex difference was approximately 1:1 as compared to 1:2 in total hip replacement.

The average age of primary knee replacement patients was 73 years, 72 yrs for males and 73 yrs for females. No change in average age was noted over the period. The proportion of patients under age of 60 years varied between 4 and 9%

Conclusion: The average age of male patients having primary hip replacement in the UK is declining and the proportion of young males undergoing hip replacement is increasing. Unless there has been a change in the incidence of osteoarthritis, these observations may reflect either a change in surgical selection criteria possibly associated with the success of surface replacement or else patients’ demand for early intervention. No changes have been observed in the age of patients undergoing knee replacement.