About Joint Replacement Surgeries

Total joint replacement is a surgical procedure in which parts of an arthritic or damaged joint are removed and replaced with a metal, plastic or ceramic device called a prosthesis. The prosthesis is designed to replicate the movement of a normal, healthy joint. Hip and knee replacements are the most commonly performed joint replacements, but replacement surgery can be performed on other joints, as well, including the ankle, wrist, shoulder, and elbow.

Types of Joint Replacement Surgeries:

• Knee Joint Replacement
• Hip Joint Replacement
• Shoulder Joint Replacement
• Ankle Joint Replacement
• Elbow Joint Replacement
• Other Joint Replacement

Knee Joint Replacement

A total knee replacement is a surgical procedure whereby the diseased knee joint is replaced with artificial material. The knee is a hinge joint which provides motion at the point where the thigh meets the lower leg. The thigh bone (or femur) abuts the large bone of the lower leg (tibia) at the knee joint. During a total knee replacement, the end of the femur bone is removed and replaced with a metal shell. The end of the lower leg bone (tibia) is also removed and replaced with a channeled plastic piece with a metal stem or a separate plastic and metal shell (depending upon type of implant used

The posterior cruciate ligament is a tissue that normally stabilizes each side of the knee joint so that the lower leg cannot slide backward in relation to the thigh bone. In total knee replacement surgery, this ligament is retained, sacrificed, or substituted by a polyethylene post. Each of these various designs of total knee replacement has its benefits and risks.

Who can go for knee Replacement?

Total knee replacement surgery is considered for patients whose knee joints have been damaged by progressive arthritis, trauma, or other rare destructive diseases of the joint. The most common reason for knee replacement in India is severe osteoarthritis followed closely by Rheumatoid arthritis of the knees.

Regardless of the cause of the damage to the joint, the resulting progressive pain and stiffness, and decreasing daily function often leads the patient to consider total knee replacement. Decisions regarding whether to undergo knee replacement surgery are not easy. Patients should understand the risks as well as the benefits before making these decisions. A detailed discussion with your surgeon will help arrive at a decision especially when there are so many implant choices now available.

About Knee replacement

This factsheet is for people who are considering having a knee replacement operation. A knee replacement replaces damaged or worn parts of the knee joint with a prosthesis made up of metal and plastic parts. Depending on the condition of your knee, a "total" or a "half" knee replacement may be done. In a half knee operation, only the inner or outer half of your knee is replaced. A total knee replacement is more commonly done.

Why have knee replacements?

Your knee joint is made up of the ends of the thigh bone (femur) and shin bone (tibia), which normally glide over each other smoothly because they are covered by smooth articular cartilage. The joint is held in place by ligaments and covered at the front by the patella (kneecap). If the cartilage is damaged by injury or worn away by arthritis for example, the ends of the bones can rub together, causing pain and restricting movement. If this happens, your knee joint can be replaced with a prosthetic one.

Types of knee replacement

There are several different types of knee replacement. Some need special bone cement to keep them in place. Other types of artificial knee parts are coated with a chemical which encourages bone to grow into it to hold the components in place

Your surgeon will discuss the various options with you.

What are the alternatives?

Surgery is usually recommended only if non-surgical treatments such as taking medicines to reduce pain and inflammation or using physical aids such as a walking stick do not help to reduce pain or improve mobility.

The Operation

A knee replacement takes one to two hours.

It is usually performed under an epidural anesthetic, which means that you will be awake throughout the procedure and will feel no pain. Once the anesthetic has taken effect, an incision, usually around 10-30cm (5-7 inches) long will be made down the front of your knee. The length of the incision may be shorter depending on the technique your surgeon is using. Your kneecap will be moved to one side so the joint can be reached. The worn or damaged surfaces will be removed from both the end of your thighbone and the top of your shin bone. The surfaces will then be shaped to fit the knee replacement. The replacement parts will be fitted over both bones.

Sometimes the part of your kneecap that is in contact with the new knee joint is replaced with a plastic prosthesis. This is called patellar resurfacing. After the new parts are fitted and tested to make sure they move smoothly, your surgeon will close the wound with stitches or clips and cover it with a dressing.

Recovering from a Knee Replacement

Once home, you should take painkillers if you need to, as advised by your surgeon or nurse. The exercises recommended by your physiotherapist are a crucial part of your recovery, so it’s essential that you continue to do them. Most people find that they are able to move around their home and manage stairs, but some routine daily activities will be difficult for a few weeks. You must follow your surgeon’s advice about driving. You shouldn’t drive until you are confident that you could perform an emergency stop without discomfort. You can go back to work after about six weeks if you have an office job. However, if your work involves a lot of standing or lifting, you should stay off for longer (usually about three months).

Hip Joint Replacement

Hip Joint Replacement is a surgical procedure that relieves pain from most kinds of hip arthritis, improving the quality of life for the large majority of patients who undergo the operation. Patients commonly undergo THR after non-operative treatments (such as activity modifications, medications for pain or inflammation, or use of a cane) have failed to provide relief from arthritis symptoms.

Most scientific studies that have followed patients for more than 10 years have found “success rates” of 90 percent or more following traditional THR. Distilled to its essentials, THR involves surgically removing the arthritic parts of the joint (cartilage and bone), replacing the “ball and socket” part of the joint with artificial components made from metal alloys, and placing high-performance bearing surface between the metal parts.

Most commonly, the bearing surface is made from a very durable polyethylene plastic, but other materials (including ceramics, newer plastics, or metals) have been used. Patients typically spend a few days in the hospital after the procedure (5 to 10 days is most typical), and some patients benefit from a short inpatient stay in a rehabilitation facility after that to help transition back to living independently at home. Most patients will walk with a walker or crutches for 4 to 6 weeks, most will use a cane for another 4 to 6 weeks after that; after that, the large majority of patients are able to walk freely. A bewildering number of different implant designs, bearing surface materials, and surgical approaches have been tried to achieve one seemingly straightforward goal: improving the quality of life for patients who have hip arthritis. As with any important life decision, it makes good sense to get educated on those issues as they pertain to your hip.

How does the hip normally work?

The hip joint is one of the true ball-and-socket joints of the body. The hip socket is called the acetabulum and forms a deep cup that surrounds the ball of the upper thigh bone, known as the femoral head. The thick muscles of the buttock at the back and the thick muscles of the thigh in the front surround the hip. The surface of the femoral head and the inside of the acetabulum are covered with articular cartilage. This material is about one-quarter of an inch thick in most large joints. Articular cartilage is a tough, slick material that allows the surfaces to slide against one another without damage

What does the surgeon hope to achieve?

The main reason for replacing any arthritic joint with an artificial joint is to stop the bones from rubbing against each other. This rubbing causes pain. Replacing the painful and arthritic joint with an artificial joint gives the joint a new surface, which moves smoothly without causing pain. The goal is to help people return to many of their activities with less pain and greater freedom of movement.

Artificial HIP

There are two major types of artificial hip replacements:

Cemented prosthesis

Uncemented prosthesis

Hybrid Prosthesis

A cemented prosthesis is held in place by a type of epoxy cement that attaches the metal to the bone. An uncemented prosthesis bears a fine mesh of holes on the surface that allows bone to grow into the mesh and attach the prosthesis to the bone.

Both are still widely used. In some cases, a combination of the two types is used in which the ball portion of the prosthesis is cemented into place, and the socket not cemented. The decision about whether to use a cemented or uncemented artificial hip is usually made by the surgeon based on your age and lifestyle, and the surgeon’s experience.

Each prosthesis is made of two main parts. The acetabular component (socket) replaces the acetabulum. The acetabular component is made of a metal shell with a plastic inner liner that provides the bearing surface. The plastic used is so tough and slick that you could ice skate on a sheet of it without much damage to the material.

The femoral component (stem and ball) replaces the femoral head. The femoral component is made of metal. Sometimes, the metal stem is attached to a ceramic ball.

The Operation

The metal ball that makes up the femoral head is then inserted.

The surgeon begins by making an incision on the side of the thigh to allow access to the hip joint. Several different approaches can be used to make the incision. The choice is usually based on the surgeon’s training and preferences. Once the hip joint is entered, the surgeon dislocates the femoral head from the acetabulum. Then the femoral head is removed by cutting through the femoral neck with a power saw. Attention is then turned toward the socket. The surgeon uses a power drill and a special reamer (a cutting tool used to enlarge or shape a hole) to remove cartilage from inside the acetabulum. The surgeon shapes the socket into the form of a half-sphere. This is done to make sure the metal shell of the acetabular component will fit perfectly inside. After shaping the acetabulum, the surgeon tests the new component to make sure it fits just right.

In the uncemented variety of artificial hip replacement, the metal shell is held in place by the tightness of the fit or by using screws to hold the shell in place. In the cemented variety, special epoxy-type cement is used to anchor the acetabular component to the bone.

To begin replacing the femur, special rasps (filing tools) are used to shape the hollow femur to the exact shape of the metal stem of the femoral component. Once the size and shape are satisfactory, the stem is inserted into the femoral canal.

Again, in the uncemented variety of femoral component the stem is held in place by the tightness of the fit into the bone (similar to the friction that holds a nail driven into a hole that is slightly smaller than the diameter of the nail). In the cemented variety, the femoral canal is enlarged to a size slightly larger than the femoral stem, and the epoxy-type cement is used to bond the metal stem to the bone.

Once the surgeon is satisfied that everything fits properly, the incision is closed with stitches. Several layers of stitches are used under the skin, and either stitches or metal staples are then used to close the skin. A bandage is applied to the incision, and you are returned to the recovery room.

Dislocation

Just like your real hip, an artificial hip can dislocate if the ball comes out of the socket. There is a greater risk just after surgery, before the tissues have healed around the new joint, but there is always a risk. The physical therapist will instruct you very carefully how to avoid activities and positions which may have a tendency to cause a hip dislocation. A hip that dislocates more than once may have to be revised to make it more stable. This means another operation.

After Surgery

What happens after surgery?

After surgery, your hip will be covered with a padded dressing. Special boots or stockings are placed on your feet to help prevent blood clots from forming. A triangle-shaped cushion may be positioned between your legs to keep your legs from crossing or rolling in.

If your surgeon used a general anesthesia, a nurse or respiratory therapist will visit your room to guide you in a series of breathing exercises. You’ll use an incentive spirometer to improve breathing and avoid possible problems with pneumonia.

Physical therapy treatments are scheduled one to three times each day as long as you are in the hospital. Your first treatment is scheduled soon after you wake up from surgery. Your therapist will begin by helping you move from your hospital bed to a chair. By the second day, you’ll begin walking longer distances using your crutches or walker. Most patients are safe to put comfortable weight down when standing or walking. However, if your surgeon used noncemented prosthesis, you may be instructed to limit the weight you bear on your foot when you are up and walking.

Your therapist will review exercises to begin toning and strengthening the thigh and hip muscles. Ankle and knee movements are used to help pump swelling out of the leg and to prevent the formation of blood clots.

Patients are usually able to go home after spending four to seven days in the hospital. You’ll be on your way home when you can demonstrate a safe ability to get in and out of bed, walk up to 75 feet with your crutches or walker, and go up and down stairs safely. And consistently remember to use your hip precautions. Patients who still need extra care may be sent to a different hospital unit until they are safe and ready to go home.

Most orthopedic surgeons recommend that you have checkups on a routine basis after your artificial joint replacement. How often you need to be seen varies from every six months to every five years, according to your situation and what your surgeon recommends.

Patients who have an artificial joint will sometimes have episodes of pain, but if you have a period that lasts longer than a couple of weeks you should consult your surgeon. During the examination, the orthopedic surgeon will try to determine why you are feeling pain. X-rays may be taken of your artificial joint to compare with the ones taken earlier to see whether the joint shows any evidence of loosening.

Rehabilitation

What should I expect during my recovery?

After you are discharged from the hospital, your therapist may see you for one to six in-home treatments. This is to ensure you are safe in and about the home and getting in and out of a car. Your therapist will review your exercise program, continue working with you on your hip precautions, and make recommendations about your safety.

These safety tips include using raised commode seats and bathtub benches, and raising the surfaces of couches and chairs. This keeps your hip from bending too far when you sit down. Bath benches and handrails can improve safety in the bathroom. Other suggestions may include the use of strategic lighting and the removal of loose rugs or electrical cords from the floor.

You should use your walker or crutches as instructed. If you had a cemented procedure, you’ll advance the weight you place through your sore leg as much as you feel comfortable. If you had a noncemented procedure, your surgeon may want you to place only the toes of your operated leg down for up to six weeks after surgery. Most patients progress to using a cane in three to four weeks.

Your staples will be removed two weeks after surgery. Patients are usually able to drive within three weeks and walk without a walking aid by six weeks. Upon the approval of the surgeon, patients are generally able to resume sexual activity by one to two months after surgery.

Home therapy visits end when you are safe to get out of the house, which may take up to three weeks.

The need for physical therapy usually ends when home care is completed. But a few additional visits in outpatient physical therapy may be needed for patients who have problems walking or who need to get back to heavier types of work or activities.

Your therapist may use heat, ice, or electrical stimulation to reduce any swelling or pain.

Therapists sometimes treat their patients in a pool. Exercising in a swimming pool puts less stress on the hip joint, and the buoyancy lets you move and exercise easier. Once you’ve gotten your pool exercises down and the other parts of your rehab program advance, you may be instructed in an independent program.

When you are safe in putting full weight through the leg, several types of balance exercises can be chosen to further stabilize and control the hip.

Finally, a select group of exercises can be used to simulate day-to-day activities, such as going up and down steps, squatting, and walking on uneven terrain. Specific exercises may then be chosen to simulate work or hobby demands.

Many patients have less pain and better mobility after having hip replacement surgery. Your therapist will work with you to help keep your new joint healthy for as long as possible. This may require that you adjust your activity choices to keep from putting too much strain on your new hip joint. Heavy sports that require running, jumping, quick stopping and starting, and cutting are discouraged. Patients may need to consider alternate jobs to avoid work activities that require heavy demands of lifting, crawling, and climbing.

The therapist’s goal is to help you maximize strength, walk normally, and improve your ability to do your activities. When you are well under way, regular visits to the therapist’s office will end. Your therapist will continue to be a resource, but you will be in charge of doing your exercises as part of an ongoing home program.