Joint Replacement

Problems with major joints like the hip and knees are usually the result of arthritis. Arthritis pain can make it hard to walk, stand or do other daily activities. By replacing the damaged parts of a joint with implants, surgeons can help reduce or even get rid of this pain.

Osteoarthritis is the most common form of arthritis. It is most often related to “wear and tear” on the joints over the years. Its onset is usually after age 50. Factors that predispose someone to this condition include family history, obesity, previous surgery or fractures in the area of the joint.

Rheumatoid arthritis is a chronic inflammatory disorder affecting the joints. These joints include the hip, knee, shoulder, elbow, wrist, hands and feet. Rheumatoid arthritis is likely autoimmune in origin, which means the body produces cells that irritate the membranes in the joint, leading to destruction of the cartilage. This form of arthritis may occur in any age group and is characterized by stiffness, swelling in the joints, pain and decreased range of motion.

The knee joint is composed of three parts: the end of the femur (thighbone), the top of the tibia (shinbone), and the patella (kneecap). In a normal knee, these three bones are covered with a smooth cartilage that cushions the bones and enables them to move easily. In the arthritic knee, the cartilage layers are destroyed, resulting in bone rubbing against bone, which causes pain, muscle weakness and limited motion.

Total knee replacement surgery involves the resurfacing of the knee joint. Metal components are attached to the ends of the bones and a plastic liner is inserted between them. The kneecap is resurfaced with a plastic liner. These components move together to allow normal motion of the knee joint. Bow leg or knock knee deformity can usually be corrected by the new alignment.

The hip joint is composed of two parts: the round head of the femur (the ball) and the acetabulum (the cup or socket in your pelvis). In a normal hip joint, these two bones are coated with a smooth articular cartilage that allows them to move against each other without friction or pain. In an arthritic hip, the cartilage layers are destroyed, and bone rubs against bone, causing pain and limiting motion.

Hip replacement surgery replaces your arthritic hip joint with an artificial joint composed of a ball component and a socket component.

The metal ball is attached to a stem that fits into your thighbone. This component can be cemented or non-cemented depending on your age and the condition of your bone.

A socket with an outer metal socket is secured into your pelvis. A combination of a cemented ball and a non-cemented socket may also be used. Your orthopedic surgeon will choose the type of prosthesis that best meets your individual needs.

Once in place, the artificial ball and socket function in essentially the same manner as your natural hip.

During ankle replacement surgery, your doctor will remove damaged parts of the bone and cartilage in your ankle joint and put in artificial parts called implants.

An ankle replacement implant has three main parts: a titanium piece that connects to the tibia bone (which is like your shinbone), a cobalt-chrome piece that connects to the talus bone (which is part of your ankle joint), and a plastic piece called polyethylene that goes between them.

Another important goal of ankle replacement surgery is to keep the ankle joint working as well as possible. Preserving motion in the ankle joint is important for walking and doing other activities without pain.

The shoulder is a complex ball-and-socket joint where the round end of the upper arm bone fits into the shallow socket of the shoulder blade, known as the glenoid. When this joint becomes damaged due to conditions like arthritis or severe fractures, shoulder replacement surgery may be recommended.

Depending on the extent of damage and the specific condition being treated, shoulder replacement surgery may involve replacing just the ball (head of the humerus bone) or both the ball and socket (glenoid).

Recovery from shoulder replacement surgery involves following a carefully structured rehabilitation program to help restore shoulder function and strength.

Anticipated results are increased mobility and range of motion in the affected joint, giving you the ability to resume an active lifestyle with little or no pain, and deformities corrected. Long-term success rates vary from 10-20 years, depending on age, weight, activity level and other factors.

Each person is different, so you should discuss expected outcomes and results with your orthopedic surgeon.

As with any surgery, you should be aware that there are risks involved. These risks could include, but are not limited to, problems with anesthesia, infection, bleeding, blood clots, nerve or blood vessel damage, dislocation or failure of the joint replacement, unresolved pain, stiffness in the joint and death. Be sure to discuss the risks and benefits of surgery with your physician.