Prevalence of knee problems in the population aged 55 years and over: identifying the need for knee arthroplasty

To determine the prevalence of knee problems in people aged 55 years and over and identify those who should be considered for knee arthroplasty.

Postal survey; questionnaires were sent to a multistage stratified probability sample of residents of North Yorkshire Health Authority aged 55 and over.

A health district with a population of 210,000 aged 55 and over.

An initial four page postal questionnaire produced an 86% response rate among 18,827 eligible patients. A subsequent detailed questionnaire sent to 1277 patients with knee problems (with a response rate of 78%) then determined the prevalence of severe pain and severe disability. Pain and disability consistent with the need to consider arthroplasty was found in 20.4/1000 (95% confidence interval 18.0 to 23.1); of these, 4.1 (2.7 to 5.8)/1000 had extreme disability. Age and sex specific rates in men who might benefit from arthroplasty were, in those aged 55-64, 12.9 (8.4 to 19.0)/1000; aged 65-74, 12.1 (7.4 to 18.4)/1000; aged 75 and over, 20.3 (12.9 to 30.5)/1000. In women aged 55-64 the rates were 12.9 (8.6 to 18.7)/1000; aged 65-74, 19.6 (13.9 to 26.7)/1000; aged 75 years and over, 42.6 (34.3 to 52.4)/1000.

Total knee replacement has until recently been considered unreliable and often seen as a last resort for many with severe knee problems. Advances in prosthesis design and surgical and anaesthetic techniques have transformed this procedure into a reliable option with a potential for reducing disability and dependency in a large number of people in the community. Understandably, the prevalence pool of those who may benefit is large; health authorities and, increasingly, general practitioners should consider purchasing more total knee replacement surgery to offer real choice to those in need.