knee microfracture rheumatoid arthritis
How the knee should work ?
The knee joint acts as a hinge between the bones of the leg.
It is actually two joints: The major joint is between the thigh bone of the upper leg (femur), and the shin bone of the lower leg (tibia). The smaller joint is between the kneecap (patella) and the femur.
A smooth, tough tissue called articular cartilage usually covers the ends of the bones within the knee joint. This protects the ends of the bones and allows them to slide smoothly over each other, without pain or too much effort.
The synovial membrane that covers the other surfaces of the knee joint produces synovial fluid. This lubricates the joint, reducing friction to further help movement.
A replacement knee will not last forever, but an artificial knee will probably last at least 10-15 years, depending on how active you are and the type of replacement you have.
As new technology continues to be developed, this figure is likely to increase.
Why knee replacement is necessary ?
Knee replacement surgery (arthroplasty) is usually necessary when a health condition or injury disrupts the normal working of the knee joint so that : -
The most common reason for knee replacement surgery is osteoarthritis.
Osteoarthritis in the knee occurs when the articular cartilage becomes damaged or wastes away through natural wear and tear. The bones then have little or no protection to prevent them rubbing against each other when the knee moves, causing pain.
The bones may then compensate by growing thicker and producing bony outgrowths to try and repair themselves, but this can actually cause more friction and pain.
Other medical conditions that may make a knee replacement necessary include:
If you're offered a knee replacement you'll normally be experiencing severe pain, swelling and stiffness in your knee joint, and will usually have a significantly reduced ability to move the joint.
However, a knee replacement is major surgery, so it's normally recommended only if non-surgical options have not helped to reduce pain or improve your mobility.
Knee replacement may be considered for adults of all ages, although young, physically active people are more likely to wear out their replacement joint. As a result, those recommended for knee replacement are typically older, less active people, as the replacement joint is less likely to wear out and need to be replaced again.
Most people who undergo a total knee replacement are aged 60-80. They will need to be well enough to cope with both a major operation and the rehabilitation afterwards.
Recently, younger and more active people have had better results with knee replacement as many replacement knees now last up to 20 years and beyond.
If you're having a knee replacement because of arthritis and also need a hip replacement, you should have the hip done first as you will need a flexible hip to do the exercises needed after a knee replacement operation.
Pain and difficulty moving the knee joint commonly happens when the articular cartilage has become damaged or worn away. This means that the ends of the bones start to rub or grind together, instead of smoothly sliding over each other.
Replacing the damaged knee joint with an artificial one can help reduce pain and increase mobility.
What should I be looking for in a specialist?
The key is to choose a specialist who performs knee replacement on a regular basis and can discuss their results with you.
This is even more important if you're having a second or subsequent knee replacement, known as revision knee replacement, which is trickier to perform. Look for a specialist who will work with you to find the best treatment for you.
Your local hospital trust site will show which specialists in your area do knee replacement. Your GP may also be able to recommend someone.
Arthroscopic washout and debridement : - An arthroscope (a tiny telescope) is inserted through small incisions in the knee. The knee is washed out with saline and any bits of bone or cartilage cleared away. It's not recommended if you have severe arthritis.
Microfracture : -This is a keyhole (minimally invasive) operation in which small holes are made in the surface layer of bone with a small sharp 'pick'. This allows cells from the deeper, more blood-rich bone beneath to come to the surface and stimulate cartilage growth. It can be a good option if you have just a small area of damaged cartilage. However, the benefits are not well proven and the results are not as good as knee replacement for severe arthritis.
Osteotomy : - This is an open operation in which the surgeon cuts the shin bone and realigns it in order to shift the load through the knee joint away from the area affected by arthritis. Sometimes used for younger people with limited arthritis, it may allow a knee replacement to be postponed. You'll usually need a knee replacement at a later date and the operation may make knee replacement surgery more difficult if it is needed.
Autologous chondrocyte implantation : - This is when new cartilage from your own cells is grown in a test tube and introduced into the damaged area. It is usually used for accidental injury to the knee rather than arthritis. As yet, it's only available in trials.
Mosaicplasty (cartilage replacement) : - This is an arthroscopic (keyhole) procedure that involves moving round plugs of hard cartilage, together with some underlying bone from another part of your knee, to repair the damaged surface. Currently, it's only available in trials.
