Joint Replacement

Joint replacement is a surgical procedure which removes a damaged joint and replaces it with a new (prosthetic) joint. A joint is the place where the ends of two bones meet. Joints are enclosed by fibrous tissue and lined with smooth tissue (synovium) which produces fluid and allows the bones to move freely past one another. Examples of joints are the knee, hip, and shoulder. Joint replacement surgery is performed by a doctor called an orthopaedic surgeon.

Other Names

• Total joint replacement
• Total joint arthroplasty

Description

Joints can be damaged by degenerative disorders like arthritis, obesity, injury, or overuse. Cartilage is dense connective tissue that normally covers the surfaces of joints, allowing the bones to move past each other freely. The loss of cartilage allows the ends of the bone to rub against each other, causing further damage, and resulting in pain, stiffness, and swelling.

Why Joint Replacement Is Done

Illustration of a surgeon operating on a patient's knee. Source: National Institute of Arthritis and Musculoskeletal and Skin Diseases

Joint replacement is usually done to improve joint mobility and quality of life and to reduce or eliminate joint pain. The most commonly replaced joints are the hips and knees. The shoulders, fingers, elbows, and ankles can also be replaced. The surgery involves removing the ends of the bone that have deteriorated and replacing them with artificial hardware.

X-ray studies and possibly arthroscopy may be performed to diagnose and evaluate the extent of the damage to bone and cartilage.

Generally, non-surgical treatments such as exercise, walking aids like braces or canes, physical therapy, or medicines and supplements are the first line of treatment. Medications for arthritis include drugs which reduce inflammation such as NSAIDs. Depending on the type of arthritis, the doctor may prescribe corticosteroids or other drugs.

Types

A new joint, called a prosthesis, can be made of plastic, metal, or both. It may be cemented into place or uncemented (new bone grows and allows fixation of the new joint). Both methods may be combined to keep the new joint in place.

Cemented

The process of cementing the prosthesis in place was developed approximately forty years ago. Recovery time is quicker than with an uncemented joint as the bone is fixed in place immediately. The cement is more likely to wear out than the natural bone in an uncemented joint, thus increasing the risk of possible revision surgery in the future. Joints are often cemented in older people who do not move around as much and in people with weaker bones.

Uncemented

An uncemented prosthesis has small holes to allow bone to grow and fix the prosthesis in place. This type of fixation is often recommended for younger, more active people and those with good bone quality. Healing time may be increased, because it takes longer for bone to grow than for the cement to work.

Preparation

Understanding the Procedure

Reading about the procedure or watching videos or looking for information on the internet may help answer questions and provide reassurance. It is also very important to ask plenty of questions of the medical staff involved in the surgery. Some questions to ask include:

• Admitting procedures in the hospital
• Length of hospital stay
• Recovery time
• Anesthesia used
• Type of replacement joint being used
• Medicines used for pain management
• Risks and complications of the procedure

Reducing the risks of surgery

It is important to discuss any underlying medical conditions with the surgeon and anesthesiologist so they can reduce the risks of the procedure. Many medicines will need to be discontinued before surgery, particularly non steroidal anti-inflammatory medicines (NSAIDS) as they carry an increased risk of bleeding. Quitting smoking and ensuring the best physical condition prior to surgery (strenghtening the muscles around the joint) may also help.

Housekeeping

It is helpful to line up help during the recovery period after surgery. Someone to do lifting, cooking, cleaning and personal care (bathing, etc) is very helpful when mobility is limited after joint replacement surgery.

How Joint Replacement Is Done

Anesthesia is administered before surgery begins. The medicine may block the pain only in one part of the body (regional), or it may put the whole body to sleep (general). The team will then replace the damaged joint with a prosthesis. The surgery will involve multiple tools including surgical saws, drills, hammers, scaples, probes, etc.

Each surgery is different. How long it takes depends on how badly the joint is damaged and how the surgery is done. To replace a knee or a hip takes about two hours or less, unless there are complicating factors. After surgery, the patient is moved to a recovery room for one to two hours until the anesthesia wears off.

Risks

Complications

• Infection can occur in or around the wound and may happen while in the hospital or after discharge. Minor infections in the wound are usually treated with antibiotics. Deep infections may need a second operation to treat the infection or replace the joint.
• Blood clots or Deep Vein Thrombosis (DVT) may develop in the deep veins of the legs after surgery. A DVT causes pain and swelling in the leg and can possibly break free and travel to the lung (Pulmonary Embolism). This condition is very serious and can lead to death. Treatment for DVT may include drugs such as heparin to thin the blood, special stockings, and exercises, and/or boots to help with circulation.
• The new joint may loosen, causing pain. If the loosening is significant, another operation may be required. New methods to attach the joint to the bone decrease the risk of joint loosening.
• Sometimes after hip or other joint replacement, the ball of the prosthesis can come out of its socket (dislocation). In most cases, the hip can be corrected without surgery. A brace may be worn for a while if a dislocation occurs.
• Sometimes, the plastic can wear, and the doctor may only replace the plastic, not the whole joint.
• Nerves near the replaced joint may be damaged during surgery, but this does not happen often. Over time, the damage often improves and may disappear. Blood vessels may also be injured.

Precautions

Any surgery has risks. Risks of joint surgery will depend on underlying medical probems at the time of surgery, the severity of the arthritis, and the specific type of surgery. More hospitals and doctors have been replacing joints for several decades, and this experience results in better patient outcomes. For answers to their questions, some people talk with their doctors, or someone who has had the surgery.

Effectiveness

Joint replacement is usually successful in more than 90% patients. When problems do occur, most are treatable.

Recovery

Illustration showing a physical therapist helping a man exercise his knee. Source: NIAMS(National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Most people can go home in the first few days after joint replacement surgery. The elderly or those people with other medical problems may need to go to an intermediate care facitilty for more healing before returning hme.

Standing and walking is encouraged soon after surgery, someimes as soon as the day of surgery. This quickens recovery time and avoids blood clots.

Walking may require a walker or crutches, depending on the joint. There may be pain and weakness in the joint from the procedure and weakness or lack of use. The pain should be controlled by pain medicine.

Physical therapy can begin the day after surgery to help strengthen the muscles around the new joint and regain motion in the joint. A physical therapist will help with gentle, range-of-motion exercises and strenthening exercises.

Statistics

Joint replacement is becoming more common. About 435,000 Americans have a hip or knee replaced each year. Current hip and knee replacements are expected to function well for 10 to 20 years in most patients. Success rates vary with the skill of the surgeon, health of the patient and surgical method chosen.

Experts on Joint Replacement

There appears to be a correlation between the number of hip and knee replacements performed in a particular medical facility and by a particular surgeon and the success rate of the procedure. ^{[1] [2]}

Most medical societies have a find a surgeon search engine which will provide names of orthopedic surgeons in a particular area. Some important questions to ask:

• Indications for surgery
• Alternatives to surgery
• How many times the surgeon performs the procedure in a year
• Success rate
• Common complications
• Follow up required

Alternatives

Arthroscopy

Arthroscopy, from the Greek arthro (joint) and skopein (to look), involves inserting a small instrument (arthroscope) which lights, magnifies, and transmits a picture from the inside of the joint to a screen. Using other instruments, the physician can repair torn joint cartilage and remove loose fragments in the joint through a small incision.

Osteotomy

This procedure involves cutting and realigning the bones in order to change the relationship between the ends of the bones and to allow them to move past each other more freely. If successful, osteotomy may delay the need for another joint surgery by as long as 10 to 20 years. This procedure is more often used in younger, active patients with mild arthritis.

Minimally invasive joint replacement

Minimally invasive knee and hip replacement surgeries involve smaller incision, less damage (cutting) to the muscle, and are usually indicated in younger, more active patients who are not obese and have no previous history of joint replacement.

Joint resurfacing

Joint resurfacing, an alternative to joint replacement, is a procedure involving removing only the diseased bone and fitting an implant onto each bone end in the joint. Less bone is removed than in traditional joint replacement, and patients typically have less recovery time and are able to lead a more active lifestyle after surgery. This procedure is often done at an earlier disease stage and leaves the option to have traditional joint replacement done at a later time, if needed. Joint resurfacing is also more often used in younger, more active patients.

Research

Scientists are studying replacement joints to find out which are best to improve movement and flexibility. They are also looking at new joint materials and ways to improve surgery. Other researchers are working to find out what causes joint damage, how to prevent it, and how to treat it.

Some scientists are studying a condition called osteolysis, a condition where bone is lost around the implant in response to inflammation. This can cause the prosthesis to loosen, and may require a second surgery.

Other scientists are also trying to find out why some people who need surgery don't choose it. They want to know what things make a difference in choosing treatment, in recovery, and in well-being.

In 2003, experts at a national conference said that surgery to replace the knee was safe and worth the cost for those who need it. They also said it helps people to move better and have less pain. ^[3]

Joseph Zuckerman, professor & chair of the Department of Orthopaedic Surgery at NYU's Hospital for Joint Diseases, discusses how innovations in materials used for joint replacement allow formerly crippled patients to live pain-free:

Clinical Trials

There are a number of active clinical trials related to joint replacement. Most are sorted by the type of joint replaced. For more information, see ClinicalTrials.gov total joint replacement.

History

How joint replacement was developed

The hip was the first joint to be successfully replaced. Hip replacement surgery was developed in the 1960s by Dr. (Sir) John Charnley. ^[4] The Charnley hip replacement was the gold standard of the time and continues to be successful 40 years later.

References

1. ↑ Katz JN, Barrett J, Mahomed NN, Baron JA, Wright RJ, Losina E. Association between hospital and surgeon procedure volume and the outcomes of total knee replacement. J Bone Joint Surg Am. 2004 Sep;86-A(9):1909-16. Abstract
2. ↑ Katz JN, Phillips CB, Baron JA, Fossel AH, Mahomed NN, Barrett J, et al. Association of hospital and surgeon volume of total hip replacement with functional status and satisfaction three years following surgery. Arthritis Rheum. 2003 Feb;48(2):560-8. Abstract | PDF
3. ↑ National Institues of Health. NIH Consensus Development Conference on Total Knee Replacement. National Institutes of Health Consensus Development Conference Statement December 8-10, 2003
4. ↑ Wroblewski B. Professor Sir John Charnley. Rheumatology. 2002; 41: 824-5 PDF

External Links

JointReplacement.com

American Academy of Orthopedic Surgeons: Total Joint Replacement

FDA Inside Look on Joint Replacement 2004

Mediescapes India:India Joint Replacement Surgery