Joint replacement procedures have become common as the active population of baby boomers continues to age. Here we present some of the most common questions we get about joint replacement. If you have other questions, please speak with your health care provider or contact our registered nurses at Nurse Direct.
What is total joint replacement?
An arthritic or damaged joint is removed and replaced with an artificial joint called a prosthesis.
What is a joint?
A joint is formed by the ends of two or more bones that are connected by thick tissues. For example, your knee joint is formed by the lower leg bone (called the tibia or shin bone) and your thighbone (called the femur). Your hip is a ball and socket joint formed by the upper end of the femur, the ball and a part of the pelvis called the acetabulum, the socket.
The bone ends of a joint are covered with a smooth layer called cartilage. Normal cartilage allows nearly frictionless and pain-free movement. However, when the cartilage is damaged or diseased by arthritis, joints become stiff and painful. Every joint is enclosed by a fibrous tissue envelope or a capsule with a smooth tissue lining called the synovium. The synovium produces fluid that reduces friction and wear in a joint.
Why is total joint replacement necessary?
The goal is to relieve the pain in the joint caused by damage to the cartilage. The pain may be so severe that a person will avoid using the joint, weakening the muscles around the joint and making it even more difficult to move. A physical examination and possibly some laboratory tests and X-rays will show the extent of joint damage. Total joint replacement will be considered if other treatment options will not relieve the pain and disability.
How is a total joint replacement performed?
First, the patient is given an anesthetic. Next, the surgeon replaces the damaged parts of the joint. For example, in an arthritic knee the damaged ends of the bones and cartilage are replaced with metal and plastic surfaces that are shaped to restore knee movement and function. In an arthritic hip, the damaged ball (the upper end of the femur) is replaced by a metal ball attached to a metal stem fitted into the femur, and a plastic socket is implanted into the pelvis, replacing the damaged socket. Although hip and knee replacements are the most common, joint replacement can be performed on joints in the ankle, foot, shoulder, elbow and fingers.
The materials used in a total joint replacement are designed to enable the joint to move just like a normal joint. The prosthesis is generally composed of two parts—a metal piece that fits closely into a matching, sturdy plastic piece. Several metals are used, including stainless steel, alloys of cobalt and chrome, and titanium. The plastic material is durable and wear-resistant (polyethylene). A plastic bone cement may be used to anchor the prosthesis into the bone. Joint replacements also can be implanted without cement when the prosthesis and the bone are designed to fit and lock together directly.
What is the recovery process?
Physicians typically encourage patients to use the “new” joint shortly after the procedure. After total hip or knee replacement, patients will often stand and begin walking the day after surgery. Initially, they will use a walker, crutches or a cane. Most patients have some temporary pain in the replaced joint because the surrounding muscles are weak from inactivity and the tissues are healing; this typically ceases in a few weeks or months.
Exercise is an important part of the recovery process, and the doctor or rehabilitation staff will discuss an exercise program for the patient. This varies for different joint replacements and to accommodate the special needs of each patient. After surgery, patients may be permitted to play golf, walk and dance. However, more strenuous sports, such as tennis or running, may be discouraged.
The motion of the patient’s joint will generally improve after surgery; the extent of improvement will depend on how stiff the joint was before surgery.
What are the possible complications?
Joint replacement surgery is successful in more than 9 out of 10 people. To reduce the risk of complication, patients must tell their physician about any medical conditions that might affect the surgery. When complications do occur, however, most are successfully treatable. Possible complications include:
Preparing for total joint replacement
- Infection: Infection may occur in the wound or deep around the prosthesis. It may happen while the patient is in the hospital, at home, or even years later. Minor infections in the wound area are generally treated with antibiotics. Major or deep infections may require more surgery and removal of the prosthesis. Any infection can spread to the joint replacement.
- Blood clots: Blood clots result from several factors, including decreased mobility that causes sluggish movement of the blood through leg veins. Blood clots may be suspected if pain and swelling develop in the calf or thigh. If this occurs, the physician may consider tests to evaluate the leg veins. Several measures may be used to reduce the possibility of blood clots, such as:
- Blood-thinning medications (anticoagulants)
- Elastic stockings
- Exercises to increase blood flow in the leg muscles
- Plastic boots that inflate with air to compress the leg muscles
- Despite the use of these preventive measures, blood clots may still occur. Joint replacement patients should contact their orthopedic surgeon if they develop swelling, redness or pain in the leg following discharge.
- Loosening: Loosening of the prosthesis within the bone may occur and will typically cause pain. If there is significant loosening, the procedure may need to be redone (called revision surgery).
- Dislocation: Sometimes with total hip replacement the ball can be dislodged from the socket. In most cases the hip can be relocated without surgery. The patient may need to wear a brace for a period of time if dislocation occurs. Most commonly, dislocations are more frequent after complex revision surgery.
- Wear: Some wear can be found in all joint replacements. Excessive wear may contribute to loosening and may require revision surgery.
- Prosthetic breakage: Breakage of the metal or plastic joint replacement is rare, but can occur. A revision surgery is necessary if this happens.
- Nerve injury: Nerves in the vicinity of the total joint replacement may be damaged during surgery, although this is uncommon. This is more likely to occur when the surgery involves correction of major joint deformity or lengthening of a shortened limb due to an arthritic deformity. Over time these nerve injuries often improve and may completely recover.
Before total joint replacement surgery, orthopedic surgeons often request that patients:
Is total joint replacement permanent?
- Donate some of their own blood so it will be available (if needed) during or after surgery
- Stop taking certain drugs before surgery
- Begin exercises to speed recovery after surgery The orthopedist will typically discuss the discharge plan with the patient before surgery, including the possible need for home therapy and rehabilitation following surgery.
Most older persons can expect their total joint replacement to last a decade or more. Younger joint replacement patients may need a second total joint replacement.