A knee replacement is major surgery, so is normally only recommended if other treatments, such as physiotherapy or steroid injections, haven't helped reduce pain or improve mobility.
You may be offered knee replacement surgery if:
Learn more in why knee replacement surgery is used.
Adults of any age can be considered for a knee replacement, although it's typically recommended for older people as young, physically active people are more likely to wear the joint out.
The earlier you have a knee replacement, the greater the chance you will eventually need further surgery.However, there is some evidence that replacing the knee joint before it becomes very stiff leads to a better outcome.
Most total knee replacements are carried out on people between the ages of 60 and 80. You will need to be well enough to cope with both a major operation and the rehabilitation afterwards.Read more aboutgetting ready for knee replacement surgeryandrecovering from knee replacement surgery.
Knee replacement surgery is a common operation and most people do not experience complications.
In some cases, the new knee joint may not be completely stable and further surgery may be needed to correct it.
If you're one of the millions of people suffering from knee pain, take heart.Heavy adults with knee osteoarthritis who lose 10% of their starting weight can significantly reduce their knee pain, walk faster and improve their mobility, a new study shows.
Obesity is a major risk factor for knee osteoarthritis, Messier says."What we found was both pathways were affected by weight loss."
Messier and colleagues recruited 454 overweight and obese adults with osteoarthritis in their knees.They reported having pain in their knees most days of the week.For the 18-month study, participants were assigned to one of three groups: a diet-and-exercise plan; a diet-only plan or an exercise-only program.
Diets were tailored to the individuals.
The diet-and-exercise group followed both the meal plan and exercise program.
• The participants in the diet-and-exercise program lost an average of about 23 pounds (about 11.4% of their starting weight) in 18 months; those who just dieted lost 19.6 pounds (9.5%); those who just exercised lost about four pounds (2%).
• Those in the diet-and-exercise group had less knee pain, walked faster and felt better about performing the activities of daily living such as walking up stairs and getting out of chairs than those in the exercise group.
• People in the diet-and-exercise group who completed the study reported a 51% reduction in pain; compared with a 25% pain reduction for people who just followed the diet and a 28% reduction in pain for those who just exercised.
• Both diet groups had greater reductions in Interleukin 6 levels — a measure of inflammation — than the exercise group.
• The weight loss in the diet intervention group helped to reduce load on the knee by 45 pounds per step.
"We are not saying weight loss and exercise should replace medications," but doctors should recommend that overweight patients with knee osteoarthritis lose weight and exercise.
Rheumatologist David Felson, a professor of medicine and epidemiology at Boston University, says the study shows that "knee pain improves and function improves substantially more when patients both lose weight and exercise. The more we emphasize this, the more we can motivate people to accomplish it."
• Osteoarthritis most commonly occurs in the weight-bearing joints of the hips, knees and lower back.