Artificial Knee Replacement
New Approach to Total Knee Replacement Computer Assisted Knee Replacement
For the properly selected patient, an artificial knee replacement, also known as total knee replacement, has been one of the greatest advancement in modern orthopaedic treatment. The procedure has been done for more than 20 years and has stood the test of time. In experience hands, the patient can expect the knee to last him 10 to 15 years. It has been shown that the lifespan of the knee is related to how well it is aligned in the leg and how well the soft tissues are balanced. While the jigs that are used to fashion or shaped the joint surfaces usually sets the artificial joint correctly, it still requires judgement on the part of the surgeon. Experienced surgeons bring their experience to bear on the surgery for minor adjustments.
Modern orthopaedic surgery calls upon the help of computers to help set the knee prosthesis (artificial knee joint) correctly. This has sometimes been referred to the use of “stealth” technology to help set the prosthesis in the best position. In actual fact, what the surgeon does is to defined certain fixed points in the patient’s lower limb at operation (termed registering these points). This is done with infrared devices which send signals to a camera which captures these points in the knee in free space (that is, in 3 dimensions). This allows the surgeon to have a virtual lower limb on which he use to “fit” the artificial joint. He has therefore a computer generated “limb” to plan the surgery. This allows him to match his judgment against a computer fitted prostheis to achieve a better “fit” for the patient before he start to cut the bone surfaces. After that, he has a second chance to check whether the joint will sit properly before the final joint is fitted on. The images and criteria for “fit” are then captured in a DVD which is to be given to the patient. Should the patient require another replacement in the future, his surgeon will have a guide for making th decisions.
It has to be noted that in experienced hands, whether the computer assisted form of surgery is used or the standard jig is used, it has not been shown to be any different in the short term. However, the new approach allows a “check” before the final prosthesis is fitted, hence providing an additional safety mechanism to try to get the best result for the patient. The procedure does add another 15 minutes or so to the operation. Today, this is often offered as a option to the patient in centers where this is available. The used of computers to enhance the surgeon’s skill is a continuing evolving process and the next giant step would probably to integrate the use of robotic technology but for the present this is still experimental.
Pre-operative xrays of Osteoarthritic Knee for Knee Replacement
Surgeons Using the Navigation for Knee Replacement
Navigation graphics show on the computer screen guides the surgeon in ensuring proper shaping of the joint surfaces for fitting of the artificial knee
Post-operative xrays of the knee joint replacement