A complete knee replacement surgery is often performed on patients whose own joints have been damaged by rheumatoid arthritis or osteoarthritis. It may also be an option for patients who have suffered a traumatic injury and developed post traumatic arthritis. The goal of the surgery is to alleviate the pain and restore functionality to the joint.

Knee replacement surgery began during the 1950s. Since that time, numerous improvements have been made to the prosthetic, the materials used, and surgical techniques. The most common technique to expose the joint is to divide the quadriceps muscle along the side where it attaches to the kneecap, or patella. The patella is then moved aside so that the surgeon can shape the ends of the femur and tibia. Cartilage is removed, and the anterior cruciate ligament is sacrificed and depending on the type of knee replacement, the posterior cruciate may be removed as well. The prosthesis is normally cemented in place, but other methods, including a process to integrate the prosthetic with the bone (porous ingroeth), are occasionally used.

On the end of the femur, the surgeon implants the femoral component, which is contoured to imitate the normal end of the bone. The component for the tibia is normally flat, with a stem that is inserted down into the bone to add greater stability. A polyethylene “cushion” is inserted into the tibial plate to replace the cartilage and provide a spacer between the two components. The patella or the kneecap may then be resurfaced with a polyethylene button. This decision is made by the surgeon and currently is more commonly done than not.

Total knee replacement surgery ^[1] has continued to evolve

. The equipment and components have improved where smaller incisions and in some cases customized components can be used. The key point to remember regarding incision size is that it may smaller and less invasive, but should be as large as it needs to be to do the job properly. Computer navigation is also continuing to be developed and may lead to better results.

Depending on the patient’s health, the average hospital stay is 3-4 days. A walker or crutches will be necessary until sufficient time has passed for the extensor (quadriceps) mechanism to function well. Physical therapy is required for several months if the patient is to recover strength and motion in the knee. It is often possible to achieve the functional range of motion by the end of the second or third week. By the first week, most patients can place full weight on their leg. Full function, with proper physical therapy, normally takes about three months, but some patients may experience a more gradual recovery that lasts longer.

Due to the demands that post-operative therapy can require, some surgeons have their patients prepare for the surgery over a three to four week period. The patient may be asked to perform daily exercises to strengthen the ankle, knee and hip and to maximize the range of motion in the leg. Some patients may need to take iron supplements for about the same length of time. If the surgeon allows the patient to store his own blood (referred to as autologous predonation) in case it is needed after surgery, arrangements must be made to accomplish the task. In addition to a full medical clearence, numerous tests must be completed before admission, such as blood tests, X-rays of the knee and chest, and an electrocardiogram.

I hope that helped you learn more about complete knee replacement surgery.

Until next time,

Stuart