Research and new developments for knee replacement surgery

Image-guided and robotic surgery

Image-guided surgery (sometimes called computer-assisted surgery) is a technique where surgery is performed with the aid of computerised images. Usually this is done by attaching infrared beacons to parts of the leg and to the operating tools. These are tracked on infrared cameras. Only about 1 in 100 knee operations are currently performed in this way.

Results so far suggest this technique offers greater accuracy in positioning the new knee joint. However, there’s no evidence that it leads to better function or survival of a knee replacement.

There are also developments in the use of robotic appliances linking operating tools with computerised scans of the knee. These may provide more accurate surgery, although these techniques are still under review.

Cementless knee replacements

Cemented knee replacements have been the most popular so far, but cementless knee replacements are possible. Components with a coating which has tiny holes in or which is made from crystal can be used. This allows the bone to grow on to and bond directly to the component. It’s thought that this could provide a longer-lasting bond than cement, which may break down over time. However, there’s currently no evidence that the components themselves are better in terms of pain relief, function, or how long they last. Research continues into the pros and cons of cementless versus cemented knee replacements.

There is an increasing use of cementless partial knee replacements as recent x-ray evidence suggests some varieties offer a better bond between the shin bone (tibia) and the metal component.

The TRIO study

Arthritis Research UK is currently funding the TRIO study, which will investigate the effect of targeting specific physiotherapy at patients who are functioning poorly after knee replacement surgery. The study aims to find out whether this early treatment improves pain, satisfaction and function after a year.