The American Academy of Orthopaedic Surgeons finds that more than 40 million people suffer from arthritis.

And for some, joint replacement surgery is the only option to help relieve the pain. Surgery is the last line of treatment; reserved for when all other modes of treatment—including physical therapy and medications—have failed to produce desired results. That being said, joint replacement surgery is a highly effective means of eliminating joint pain, as well as correcting a deformity and restoring mobility. Joint replacement surgery is also performed to treat advanced arthritis.

Candidates for joint replacement surgery often have severe joint pain, stiffness, limping, muscle weakness, limitation of motion, and swelling. Depending on the joint affected and the amount of damage, ordinary activities such as walking, putting on socks and shoes, getting into and out of cars, and climbing stairs may become difficult.

The most common causes of joint dysfunction are osteoarthritis and rheumatoid arthritis. While nobody is certain what causes arthritis, a number of factors may contribute to joint deterioration and lead to arthritis. Some of these factors include:

• Heredity
• Developmental abnormalities of joint formation
• Genetic predisposition to abnormal cartilage metabolism
• Minor repetitive injuries
• Severe trauma to the joint cartilage (cushioning tissue at the end of the bones)

While being overweight does not necessarily cause arthritis, it contributes to early and more rapid progression of joint problems.

Joint replacement surgery is designed to replace the damaged cartilage and any associated loss of bone structure. The procedure itself is a resurfacing of the damaged joint, and relies on the patient’s muscles and ligaments for support and function. The prosthesis (replacement joint) is made of titanium or cobalt chrome alloy and polyethylene (plastic). It can be affixed to the bone with acrylic cement or it can be press-fit, which allows bone to grow into the implant. Once the joint replacement is in place, its motion and function are restored through physical therapy. The three most common joint replacement surgeries are hip, knee, and shoulder.

Hip Replacement
Approximately 240,000 total hip replacements are performed in the United States each year. Total hip replacement is a surgical procedure for replacing the hip socket and the “ball” or head of the thigh bone (femur). The surgeon resurfaces the socket and ball where cartilage and bone have been lost. An artifi cial ball and socket are then implanted into healthy bone. Most candidates for total hip replacements have advanced changes in the hip joint caused by arthritis. A hip replacement is recommended if the joint pain has become unbearable and when the loss of function prevents a person from being able to perform activities of daily living.

Hip Replacement Aftercare
Most patients can stand at their bedside on the first day after surgery and can even begin exercising. By the second day after surgery, most patients begin walking with the aid of a walker or crutches, and can apply 50 to 75 percent of their weight on the affected leg. Most younger patients are allowed to go home by the fourth or fifth day after surgery. Older individuals and patients who have significant health problems are usually referred to a rehabilitation facility for an additional 7 to 10 days, for more therapy.

All patients remain on either crutches or a walker for about 4 weeks after surgery. They are then allowed to place full weight on their extremity while using a cane for balance. The cane also prevents the muscles from becoming fatigued. Generally, within 6 to 12 weeks of surgery, the person can stop using the cane or walker (upon recommendation of the doctor or therapist) and the hip can support the person’s full weight. Patients who have weaker muscles may need to use the cane or walker for a longer period.

Once the patient has participated in the recommended course of therapy after the total hip replacement, they can engage in most activities. Patients can walk, ride bicycles, ski, play golf and perform other, similar activities. Activities that require repetitive impact on the joint (such as tennis and racquetball) should be avoided or practiced only occasionally.

Knee Replacement
Knee replacement surgery is performed to treat advanced arthritis. When arthritis in the knee joint or joints has progressed to the point where medical management is not effective, or deformity has become severe and debilitating, knee replacement surgery may be recommended.

Joint surgery in the knee is needed when damage occurs to the coating or gliding surface of the joint, called the articular cartilage. Depending on the amount of damage, ordinary activities such as walking and climbing stairs may become diffi cult. Damage to the knee joint cartilage and underlying bone may also result in deformity. Knock-knee or bow-legged deformities and unusual knee sounds may become more obvious as the degeneration worsens. Knee replacement surgery is designed to replace this damaged cartilage or gliding surface, as well as any associated loss of bone structure or ligament support. The material used for knee replacement is similar to that mentioned for hip replacements.

Knee Replacement Aftercare
Most patients who undergo total knee surgery experience a dramatic improvement within 3 months. The pain caused by the damaged knee is relieved when a new gliding surface is constructed. Patients are usually standing and moving the joint the day after surgery. After about 6 weeks, most patients are walking comfortably with minimal support, however, it may take 6 months to 1 year before the optimal benefi t is achieved. After muscle strength is restored, patients who have knee replacement surgery can enjoy most activities (except running and jumping).

When knee replacement procedures were first performed in the early 1970’s, it was thought that the average total knee implant would last approximately 10 years. It is now known that approximately 85 percent of the knee implants will last 20 years. Improvements in surgical techniques, prosthetic designs, bearing surfaces and fi xation methods may allow these implants to last even longer!

Shoulder Replacement
Total shoulder joint replacement is usually required for those who have severe forms of osteoarthritis or rheumatoid arthritis but, more rarely, for those who have sustained severe trauma from a shoulder fracture.

Similar to the hip joint, the shoulder is a large ball-and-socket joint. The primary indication for a total shoulder replacement is pain that is not being relieved through therapy or other treatment methods. Pain may be the result of abnormalities and changes in the joint surfaces as a result of arthritis or fractures. The primary goal of total shoulder replacement surgery is to alleviate pain with secondary goals of improving motion, strength, and function.

Shoulder Replacement Aftercare
A successful outcome to your total shoulder joint replacement depends heavily on the meticulous performance of your prescribed exercises. Through a structured exercise program, your muscles will be methodically and progressively stretched and strengthened over one year’s time. The desired effect is the optimal function of your shoulder replacement. In certain situations, prolonged formal physical therapy after hospital discharge may be required. This can be done during outpatient therapy at home. Most patients, however, do not require any formal outpatient therapy.

Your rehabilitation will be ongoing and progressive. It may take 6 months to 1 year to achieve the optimal benefit. It is important to realize that progress is sometimes slow and not always steady. You must continue your therapy program without getting discouraged. The physician will monitor your progress during visits at intervals of six weeks for the first four to five months, and then less frequently for one year.

With current improvements in materials, prosthetic designs, and surgical techniques, more than 95 percent of contemporary total joint replacement procedures should last 15 to 20 years or more. Routine follow-up after recovery from surgery should include X-rays after the first, third, fifth, and seventh years. Thereafter, X-rays should be taken every 2 years to make sure that wear on the replaced joint is not occurring.