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
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.