How long does a knee replacement last?

Many knee replacements work for decades

Researchers followed many people with knee replacements. About 82.3% hadn't needed another knee operation at twenty-five years. That later operation is called a revision.

The number doesn't promise your result. Some people still felt stiff while the parts stayed in place. Others needed more care.

Knee parts and surgery have changed over time. Older results won't match every newer operation. Ask your surgeon what fits your case.

Age changes the chance of another operation

Age affects how long the new parts must work. After age seventy, the lifetime chance of another operation was about 5%. Younger people had more years for trouble to start.

Your age isn't the whole answer. Your health, weight, and activity matter too. So does the damage inside your knee.

Ask how worn parts might feel. Loosening may cause new soreness or poor support. Heat, swelling, or sudden illness can mean infection.

Walking, stairs, and sleep tell you when to talk

Time your usual walk this week. Note how often your knee wakes you. One good morning doesn't answer the question.

Stronger muscles can support your knee. A cane or brace may also help. Keep moving gently if you can.

Arrange an exam if those steps don't help. You'll discuss your goals and health risks. The doctor can explain choices besides surgery.

Sources

1. Pooled national registry data covering 299,291 total knee replacements across 14 registries give a 25-year all-cause survival of 82.3% (95% CI 81.3-83.2); pooled 25-year survival of unicompartmental knee replacements across four registries was 69.8% (67.6-72.1).

   Evans JT, Walker RW, Evans JP, et al. — How long does a knee replacement last? A systematic review and meta-analysis of case series and national registry reports with more than 15 years of follow-up.. The Lancet, 2019. DOI: 10.1016/S0140-6736(18)32531-5.

2. In 63,158 hip and 54,276 knee replacement patients in the Clinical Practice Research Datalink, the lifetime risk of requiring revision surgery was about 5% for patients operated on after age 70 with no sex difference, but rose to 35% (95% CI 30.9-39.1) for men having surgery in their early 50s, with women's risk about 15% lower at the same age. Median time to revision for patients operated on younger than 60 was 4.4 years. The authors state their evidence challenges the trend toward more replacements in younger patients.

   Bayliss LE, Culliford D, Monk AP, et al. — The effect of patient age at intervention on risk of implant revision after total replacement of the hip or knee: a population-based cohort study.. The Lancet, 2017. DOI: 10.1016/S0140-6736(17)30059-4.

3. A systematic review of prospective studies in unselected osteoarthritis patients found that the proportion reporting an unfavourable long-term pain outcome ranged from about 7% to 23% after hip replacement and 10% to 34% after knee replacement; in the best-quality studies, 9% or more after hip and about 20% after knee replacement.

   Beswick AD, Wylde V, Gooberman-Hill R, et al. — What proportion of patients report long-term pain after total hip or knee replacement for osteoarthritis? A systematic review of prospective studies in unselected patients.. BMJ Open, 2012. DOI: 10.1136/bmjopen-2011-000435.