Do cementless knee replacements work as well as cemented ones?
Short answerIn one randomised trial, the two types gave similar results at six years. More people with a cementless knee were very satisfied. One single-centre trial is not enough to settle the question.
Evidence grade
Does not helpNot enough evidenceHelps a littleGood evidence
Not enough evidence yet
What it is
Most knee replacements are held in place with bone cement. A cementless knee has a rough, porous surface that the bone grows into. Cementless knees are now used more often than in the past.
What the research shows
randomised 147 people, and 141 were followed. They received a cemented or a cementless knee of the same design. At about two years, there was no difference in any knee score. The cementless group had a shorter operation, 82 minutes against 94 minutes. Blood loss was similar.
. Of the 129 still in the study, 127 were assessed. No knee in either group had been revised. There was no difference in patient-reported function. A higher share of the cementless group were extremely or very satisfied with their knee. There was no sign of loosening on X-rays in either group.
This was one centre, one implant design and a small number of people. Six years is also a short time for a knee replacement that should last many years.
What the Australian joint registry shows
In the Australian joint registry, cementless knees needed another operation slightly more often than cemented knees. At 20 years about 10 in 100 cementless knees had been redone, compared with about 8 in 100 cemented knees and 7 in 100 hybrid knees, where only the shin bone part is cemented . For the most common knee design, cementless fixation of the shin bone part did worse in all age groups and in both men and women.
The registry is not a trial, but it follows hundreds of thousands of knees for up to 20 years. The trials on this page were too small and too short to show a difference of this size. Cementless knees have become more popular in Australia in recent years.
Risks and effort
Both types carry the usual risks of knee replacement, including infection, stiffness, clots and the need for further surgery. A cementless knee relies on the bone growing into the implant. The trial excluded people with weak bone, so the results may not apply to them.
This trial did not show a difference at six years. Longer follow up is needed. In the Australian joint registry, cemented and hybrid knees were redone slightly less often than cementless knees over 20 years, about 8 and 7 in 100 compared with about 10 in 100 .
Is a cementless knee suitable for everyone?
No. Your surgeon will check the quality of your bone.
Is the recovery different?
The trial found similar knee scores at the early checks.
Sources
Select a source to read what the study or guideline found, in plain words, with a link to the original.
Last reviewed 24 October 2026. Next review due October 2027.
