How long have knee replacements been performed?
Modern knee replacement surgery began in the early 1970s. Over the last 30 years, the procedure has been refined and improved, and is now one of the most successful surgical procedures for the treatment of knee arthritis. Assuming there are no breakthrough preventive treatments for the conditions that lead to total knee arthroplasty, by the year 2030 the American Academy of Orthopaedic Surgeons estimates that about 450,000 total knee arthroplasty procedures will be performed every year. This is a large increase from the 245,000 total knee replacements performed in 1996, and reflects the aging of our active and mobile culture.
Why is total knee replacement surgery performed?
Knee replacement surgery is performed to treat advanced or end-stage arthritis. When arthritis in the knee joint or joints has increased to the point where medical management is not effective, or deformity has become severe and debilitating (reduces the person’s strength), knee replacement surgery might be indicated.
What is knee arthritis?
Arthritis is a general term that describes inflammation (swelling) and deterioration in joints. In the knee, arthritis results from damage to the coating or gliding surface called the articular cartilage. Depending on the amount of damage, ordinary activities such as walking and climbing stairs might become difficult.
Damage to the knee joint cartilage and underlying bone might also result in deformity. Knock-knee or bow-legged deformities and unusual knee sounds (crepitus) might become more obvious as the degeneration (deterioration) worsens.
What causes knee joint degeneration?
Mechanical "wear and tear" on a person's knees over a lifetime seems to be an obvious explanation for the increase of arthritis with age, but the answer is not that simple. The current view is that a number of factors act together to cause knee deterioration. Some of these factors include heredity, developmental abnormalities of knee formation, genetic tendency to abnormal cartilage metabolism, major or minor repetitive injuries, and certain occupations. While being overweight does not necessarily cause arthritis, it certainly contributes to early and more rapid development of knee problems.
Who is a candidate for knee replacement surgery?
People with painful knee deformities, severe degenerative X-ray changes, or advanced symptoms of arthritis are candidates for knee replacement surgery. Symptoms of advanced end-stage knee arthritis include:
- Muscle weakness
- Limitation of motion, and
Family physicians, internists, rheumatologists, physiatrists, and orthopaedic surgeons are all trained to manage knee arthritis and can perform an initial evaluation. When medications (oral and injectable), diet, and physical therapy fail to manage these symptoms, knee replacement surgery may be indicated and performed by an orthopaedic surgeon.
Total knee replacement surgery provides relief for patients with severe pain caused by degeneration of the cartilage in the knee, advanced arthritis, or serious knee injuries. Approximately 85 to 90 percent of all total knee replacement operations performed are successful for approximately 10 to 15 years, depending on the patient's level of activity, after which time revision surgery may be recommended by your doctor.
What causes the pain?
Degenerative changes or injury can cause damage to some of the structures in the knee, causing pain and discomfort, and limiting normal activities. One of these conditions, called osteoarthritis, causes the cartilage that normally helps to cushion the bones to wear down, making the bones rub together, which causes pain. Other conditions that may lead to total knee replacement surgery are rheumatoid arthritis and post-traumatic arthritis. Your doctor may try to reduce your discomfort with pain medication, weight management and physical therapy, but total knee replacement may be recommended if these remedies are unsuccessful.