Knee replacement or knee arthroplasty refers to a surgical procedure during which the damaged components of the knee joint are removed and then replaced with artificial components. The procedure can be beneficial for individuals who have had knees debilitated by degenerative joint disease, other forms of arthritis, deformity, infection, or as result of trauma. Knee replacement may be recommended in situations where conservative non-surgical therapy or other procedures have not provided relief from pain, stiffness, and loss of function.
The knee joint is a hinge joint connecting the thigh bone (femur) to the shin bone (tibia). It is protected in the front by the patella (kneecap), which is a small flat triangular bone that also plays a role in knee extension. There are four major ligaments in the knee. These ligaments, along with help from the quadriceps muscles in the front of the thighs and the hamstrings in the back of the thighs, act to stabilize the knee and keep it moving in the proper direction. Two concave pads of cartilage called menisci, which are located between the ends of the femur and tibia, minimize friction in the joint and act as shock absorbers.
The largest joint in the body, the knee coordinates with the pelvis, hip, upper leg, lower leg, ankle and foot to facilitate a complete range of lower body movements. It is a strong weight-bearing joint that allows the leg to flex, extend, and twist slightly from side to side. Having healthy knees is essential to perform many daily activities.
Knee replacement is a very common and effective joint replacement surgery that is typically performed after less invasive treatment options have failed. The most frequent reason for the procedure is severe osteoarthritis of the knees. The goal of a knee replacement is to alleviate symptoms and to restore normal function to the knee. The three main areas of the knee involved in the procedure are the lower end of the thigh bone (femur), the upper end of the shin bone (tibia), and the area behind the kneecap (patella).
In a total knee replacement, all of the joint surfaces in the knee are replaced with artificial materials. During a total knee replacement surgery, damaged cartilage and bone are removed from the joint ends of the thigh and shin bones, and as needed from the back of the kneecap. The removed cartilage and bones are then replaced with implants to recreate the joint surfaces. A plastic spacer is then placed between the new metal ends of the thigh bone and shin bone to create a smooth gliding joint surface. In patients with only limited arthritis or damage to the knee joint, a partial or unicompartmental knee replacement may be a suitable option.
A high percentage of individuals who have knee replacement surgery experience a significant relief of symptoms along with an improvement in mobility. Physical therapy begins a short time after the procedure with total rehabilitation taking up to several months. In order to achieve the maximum benefits of the procedure, it is important to adhere to the post-operative guidelines as well as a well-planned rehabilitation program.