Arthroplasty Health Article

Definition

Arthroplasty is surgery performed to relieve pain and restore range of motion by realigning or reconstructing a dysfunctional joint.

Purpose

The goal of arthroplasty is to restore the function of a stiffened synovial joint and relieve pain. As a surgical procedure, it is usually performed when medical treatment has not improved function in the affected joint. There are two types of arthroplastic surgery: joint resection and interpositional reconstruction. Joint resection involves removing a portion of the bone from a stiffened joint, increasing the space between the bone and the socket to improve the range of motion. Scar tissue eventually fills the gap, narrowing joint space again. Pain is relieved and motion is restored, but the joint is less stable.

Interpositional reconstruction is surgery to reshape the joint and add a prosthetic disk between the two bones forming the joint. The prosthesis can be made of plastic, metal, ceramic material, or formed from such body tissue as skin, muscle, or fascia. When interpositional reconstruction fails, total joint replacement may be necessary. Joint replacement is also called total joint arthroplasty.

In recent years, joint replacement has become the operation of choice for most chronic knee and hip problems, particularly because of advances in the type and quality of prostheses (articifical joints). Elbow, shoulder, ankle, and finger joints are more likely to be treated with joint resection or interpositional reconstruction.

Arthroplasty is performed on people suffering from severe pain and disabling joint stiffness. Osteoarthritis (OA), a degenerative joint disease, is the most common condition causing joint destruction with pain and impaired movement. Other causes include rheumatoid arthritis (RA), hemophilia, synovitis, and rare bone diseases, which are all known to destroy cartilage. Joint resection, rather than joint replacement, is more likely to be performed on people with rheumatoid arthritis, especially when the elbow joint is involved. Joint replacement is usually reserved for older patients, because of the limited longevity of benefits. The younger the patient, the greater the reliance on medical treatment.

Demographics

The American Academy of Orthopaedic Surgeons reports that approximately 713,000 arthroplasty surgeries are performed annually in the United States. Of these, an average of about 362,000 are knee surgeries and 295,000 are hip surgeries. The remainder are ankle, shoulder, wrist, and hand surgeries. Joint replacement surgeries are increasing; for example, 259,000 total knee replacements were performed in 1997 and 299,000 were performed in 2000.

Because the primary underlying condition in patients undergoing arthroplasty is osteoarthritis, a common cause for disability among older adults, the majority of patients undergoing this surgery fit the demographic profile for osteoarthritis. Osteoarthritis is the most common type of arthritis, with over twenty million people in all parts of the United States. Both men and women have the disease; under age 45 men are more often affected, though more women than men are affected after age 45. Younger people can have the disease after a joint injury. Arthroplasty is reserved for the most severely afflicted—approximately 3% of all patients with osteoarthritis, women more often than men. Two and one-half million people in the United States have rheumatoid arthritis, which can strike people of all ages. Very few have arthroplasty because this chronic crippling disease affects not only multiple joints but other parts of the body as well, including the immune system. Patients weakened by this disease are more subject to infection and less likely to enjoy positive surgical results.

Description

Arthroplasty is performed under general (affecting the entire body) or regional (numbing a specific area of the body, such as spinal block) anesthesia in a hospital, by an orthopedic surgeon. Although many hospitals and medical centers perform common types of joint surgery, orthopedic hospitals that specialize in joint surgery tend to have higher success rates than less specialized centers.

In joint resection, the surgeon makes an incision at the joint, then carefully removes the minimum amount of bone necessary to allow free motion. The more bone that remains, the more stable the joint. Ligament attachments are preserved as much as possible. In interpositional reconstruction, both bones of the joint are reshaped, and a disk of material is placed between the bones to prevent their rubbing together. Length of hospital stay depends on the joint affected; in the absence of complications, a typical stay is only a few days.