The knee is a “hinge” joint where the thigh bone (femur) and the shin bone (tibia) meet. The knee cap (patella) glides over the femur when the knee moves. In a healthy joint, a layer of smooth cartilage cushions the bone ends, working together with muscles, tendons and ligaments to allow you to bend your knee easily. Arthritis — particularly “wear-and-tear” arthritis or osteoarthritis — as well as certain knee injuries and diseases can damage the cartilage, causing the bones to rub together and leading to pain and stiffness.
While there are several nonsurgical and surgical treatment options available for patients with arthritis and other serious conditions, those with severe pain and stiffness that does not respond to conservative treatments may require joint replacement surgery to relieve pain and restore motion to the joint.
In a total knee replacement, the damaged ends of the bones are removed and replaced with a prosthesis made of metal and plastic. These artificial parts allow the joint to move smoothly so the patient experiences pain relief and a better quality of life.
Your doctor will conduct a thorough medical history that includes x-rays, strength and range-of-motion tests and a series of questions to determine which type of implant and procedure technique is right for you. Any questions or concerns you may have will be answered prior to surgery as well to ensure that you are comfortable and confident in your knee replacement procedure.
The total knee replacement procedure is performed in a hospital under general anesthesia. During the procedure, an incision is made in the knee to access the joint and allow your surgeon to remove the damaged bone and cartilage on the end of the femur and tibia. Precise removal is essential to achieving successful results for each individual procedure.
Once the damaged tissue is removed, the prosthetic device is inserted and may be either cemented or pressed into place. Cemented knee replacements are most commonly used, and are fixed into the joint for immediate support. Press-fit knee replacements are designed to have the surrounding bone grow into the implant for long-term joint stability.
Recent advances in surgical technology make it possible to perform minimally invasive joint replacements. Traditional knee replacement surgery involves an 8-12 inch incision. Various minimally-invasive techniques allow the joint to be replaced with less cutting and manipulation of muscles, tendons and ligaments around the joint. There are other potential advantages to minimally invasive surgery that help make the surgery safer and allow patients to enjoy a faster and less painful recovery. Our doctors will discuss with you whether you are a candidate for minimally invasive knee replacement surgery.
After the procedure, the patient rests in a recovery room and then in a hospital room. A short hospital stay is likely needed, depending on the type of procedure performed and the overall health of the patient. Patients usually experience immediate relief from the joint pain suffered before the replacement. However, there will be some post-operative discomfort, which can be managed with pain medication provided by your doctor.
Physical therapy starts right away in the hospital to speed healing and to ensure that the patient enjoys full use of the joint. Therapy progresses from use of walkers and crutches to walking on stairs and slopes, with home exercises to supplement formal sessions. In addition, continuous passive motion (CPM) machines can reduce recovery time and the risk of muscle contracture without straining the joint.
Knee replacements today last about 20 years in 85-90% of well-selected patients. Patients can enjoy effective pain relief and restored motion that allow them to resume an active lifestyle. Like natural joints, these devices will wear out over time and frequent use, at which point patients may require an additional procedure.
Although considered a safe procedure for most patients, there are certain risks associated with all surgical procedures. Some of these risks may include infection, blood clots, scarring, limited range of motion, nerve damage, implant rejection and others. These risks are considered rare, as most patients are able to achieve effective pain relief through this safe procedure. Your doctor will discuss the risks of surgery with you prior to your procedure to ensure complete patient understanding for the most effective results.