Knee replacements now cost the NHS more each year than total hip replacements. An ageing population and an increase in obesity-related conditions are placing an increasing strain on NHS resources, with the number of knee replacements performed rising by 15 per cent last year from 59,391 to 68,300. Doctors predict that by 2010, suchoperations could cost the NHS almost pounds 1 billion per year.
The average age for a total knee replacement is 70. Osteoarthritis, one of the four most common problems linked to obesity, is the major cause of surgery. Overweight and obese people are 24 per cent more likely to require knee surgery. About 68,300 knee replacements were performed in the UK in 2002, costing the NHS in the region of pounds 375 million (Blakemore, 2003).
There are more replacement operations performed on the knee than any other joint in the body: more than 600 000 total knee replacements are performed each year globally. The annual total global knee market is estimated to be worth $2 billion (Advanced Ceramics Report).
Total knee replacement, which is defined as the surgical insertion of a hinged artificial joint, relieves pain and restores motion to a knee which is affected by arthritis or injury. In a standard total knee replacement, the damaged areas of the thighbone, shinbone and kneecap are removed and replaced with prostheses.
The diseased bone surfaces are removed and a two-piece metallic hinge is cemented into the cavities of the upper and lower leg bones (femur and tibia). After surgery, the knee is held in position, usually with a plaster cast. The ends of the remaining bones are smoothed and reshaped to accommodate the prostheses. Pieces of the artificial knee are typically held in place with bone cement or plaster cast. Physical therapy includes exercise and whirlpool baths. The mobility and range of motion of the joint increase slowly.
It is healing of the muscle and tendon that causes much of the pain during recovery, as clients must stretch those injured parts in order to regain knee motion. Despite excruciating pain and decreased mobility, many people with knees damaged by arthritis put off joint-replacement surgery out of fear and uncertainty.
The largest joint in the body, the knee joint is formed where the lower part of the thighbone (femur) joins the upper part of the shinbone (tibia) and the kneecap (patella). Shock-absorbing cartilage covers the surfaces where these three bones touch (Snell, 2000). In a normal knee, the bone surfaces that come together at the joint-thighbone, shinbone and kneecap--are smooth and hard. A cushioning layer of tissue (cartilage) prevents direct contact between these bones. When the cartilage is damaged, these bones rub together, causing friction, pain and, eventually, deterioration of the bone surfaces (Bren, 2004). As it is the largest joint in the body, it is also prone to pain and loss of function and stability, which therefore requires surgery to be done.
Remedies included not using the affected joint but more recently researchers have found some substances such as glucosamine and chondroitin, as well as apple pectin which have in some cases been able to stimulate regeneration of the cartilage. But often the recommendation consists of losing weight, use of pain killers from aspirin to ibuprophen, and the cox 2 inhibitors, one of which (Vioxx) got into trouble recently because they found it enhanced heart problems. Injecting a gel substitute into the knees has helped but often the relief lasts for only about six months.
The ultimate remedy by the doctors is total knee replacement. What this means is that they open up the knee, cut off or...