Joint Replacement 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 which 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 the damage done to
the cartilage. The pain may be so severe, a person will avoid using the joint,
weakening the muscles around the joint and making it even more difficult to move
the joint. A physical examination, possibly some laboratory tests and x-rays
will show the extent of damage to the joint. Total joint replacement will be
considered if other treatment options will not relieve your pain and disability.
How is a total joint replacement performed?
You will be given an anesthetic and the surgeon will replace 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 other joints, including 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 your 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?
In general, your orthopaedist will encourage you to use your "new" joint shortly
after your operation. After total hip or knee replacement you will often stand
and begin walking the day after surgery. Initially, you will walk with 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, but it
will end in a few weeks or months.
Exercise is an important part of the recovery process. Your orthopaedic surgeon
or the staff will discuss an exercise program for you after surgery. This varies
for different joint replacements and for differing needs of each patient.
After your surgery, you may be permitted to play golf, walk and dance. However,
more strenuous sports, such as tennis or running, may be discouraged.
The motion of your joint will generally improve after surgery. The extent of
improvement will depend on how stiff your joint was before the surgery.
What are the possible complications? Tell
your orthopaedic surgeon about any medical conditions that might affect the
surgery. Joint replacement surgery is successful in more than 9 out of 10
people. When complications occur, most are successfully treatable. Possible
complications include:
Infection-Infection may occur in the wound or deep around the prosthesis. It may
happen while in the hospital or after you go home. It may even occur 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 in your body can spread to your joint replacement.
Blood Clots-Blood clots result from several factors, including your decreased
mobility causing sluggish movement of the blood through your leg veins. Blood
clots may be suspected if pain and swelling develop in your calf or thigh. If
this occurs, your orthopaedic surgeon may consider tests to evaluate the veins
of your leg. Several measures may be used to reduce the possibility of blood
clots, including:
blood thinning
medications (anticoagulants)
elastic
stockings
exercises to
increase blood flow in the leg muscles
plastic boots
that inflate with air to compress the muscles in your legs
Despite the use of these preventive measures, blood clots may still occur. If
you develop swelling, redness or pain in your leg following discharge from the
hospital, you should contact your orthopaedic surgeon.
Loosening-Loosening of the prosthesis within the bone may occur after a
total joint replacement. This may cause pain. If the loosening is significant, a
revision of the joint replacement may be needed. New methods of fixing the
prosthesis to bone should minimize this problem.
Dislocation-Occasionally, after total hip replacement the ball can be
dislodged from the socket. In most cases, the hip can be relocated without
surgery. A brace may be worn for a period of time if a 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 occurs.
Nerve injury-Nerves in the vicinity of the total joint replacement may be
damaged during the total replacement surgery, although this type of injury is
infrequent. 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.
Preparing for total joint replacement
Before surgery, your orthopaedic surgeon will make some recommendations, such as
suggesting that you:
donate some of your own blood so that, if needed, you may receive it during or
after surgery
stop taking some drugs before surgery
begin exercises to speed your recovery after surgery
evaluate your need for discharge planning, home therapy and rehabilitation after
surgery
Is total joint replacement permanent?
Most older persons can expect their total joint replacement to last a decade or
more. It will give years of pain-free living that would not have been possible
otherwise. Younger joint replacement patients may need a second total joint
replacement. Materials and surgical techniques are improving through the efforts
of orthopaedists working with engineers and other scientists. The future is
bright for those who choose to have a total joint replacement to achieve an
improved quality of life through greater independence and healthier pain-free
activity.
The
materials used in a total joint replacement are designed to enable the joint to
move just like your 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. 
Tell
your orthopaedic surgeon about any medical conditions that might affect the
surgery. Joint replacement surgery is successful in more than 9 out of 10
people. When complications occur, most are successfully treatable. Possible
complications include: 
blood thinning
medications (anticoagulants)