Total Knee Replacement in Tunisia

Knee Anatomy

The knee is the largest joint in the body and having healthy knees is necessary to perform most daily activities.
The knee is made up of the lower end of the femur (thighbone), the upper end of the tibia (shinbone), and the patella (kneecap). The ends of these three bones where they touch are covered with articular cartilage, a smooth substance that protects the bones and enables them to move easily.
The menisci are located between the femur and the tibia. These C-shaped wedges act as "shock absorbers" that cushion the joint.
Large ligaments hold the femur and tibia together and provide stability. The long thigh muscles give the knee its strength.
All remaining surfaces of the knee are covered by a thin lining called the synovial membrane. This membrane releases a fluid that lubricates the cartilage, reducing friction to nearly zero in a healthy knee.
Normally, all of these components work in harmony. But disease or injury can disrupt this harmony, resulting in pain, muscle weakness, and reduced function.

When to get a replacement

Arthritis is the most common cause of chronic knee pain and disability. Although there are many types of arthritis, most knee pain is caused by just three types: osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis.
Osteoarthritis: This is an age-related "wear and tear" type of arthritis. It usually occurs in people 50 years of age and older, but may occur in younger people too. The cartilage that cushions the bones of the knee softens and wears away. The bones then rub against each other, causing knee pain and stiffness.
Rheumatoid Arthritis: This is a disease in which the synovial membrane that surrounds the joint becomes inflamed and thickened. This chronic inflammation can damage the cartilage and eventually cause cartilage loss, pain, and stiffness. Rheumatoid arthritis is the most common form of a group of disorders called "inflammatory arthritis."
Post-traumatic Arthritis: This can follow a serious knee injury. Fractures of the bones surrounding the knee or tears of the knee ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function.

Procedure

A knee replacement (also called knee arthroplasty) might be more accurately termed a knee "resurfacing" because only the surface of the bones is actually replaced. There are four basic steps to a knee replacement operation:
Prepare the bone: The damaged cartilage surfaces at the ends of the femur and tibia are removed along with a small amount of underlying bone.
Position the metal implants: The removed cartilage and bone are replaced with metal components that recreate the surface of the joint. These metal parts may be cemented or "press-fit" into the bone.
Resurface the patella: The undersurface of the patella (kneecap) is cut and resurfaced with a plastic button. Some surgeons do not resurface the patella, depending on the case.
Insert a spacer: A medical-grade plastic spacer is inserted between the metal components to create a smooth gliding surface.
The procedure itself takes about 1 to 2 hours. Your orthopedic surgeon will remove the damaged cartilage and bone, and then position the new metal and plastic implants to restore the alignment and function of your knee.

How your new knee is different

Improvement of knee motion is a goal of total knee replacement, but restoration of full motion is uncommon. The motion of your knee replacement after surgery can be predicted by the range of motion you have in your knee before surgery. Most patients can expect to be able to almost fully straighten the replaced knee and to bend the knee sufficiently to climb stairs and get in and out of a car. Kneeling is sometimes uncomfortable, but it is not harmful. Most people feel some numbness in the skin around your incision. You may also feel some stiffness, particularly with excessive bending activities. Most people feel or hear some clicking of the metal and plastic with bending or walking. This is normal. These differences often diminish with time and most patients find them tolerable compared with the pain and limited function they experienced prior to surgery. Your new knee may activate metal detectors required for security in airports and some buildings. Inform the security agent about your knee replacement if the alarm is activated.

How to protect your replacement

Participate in regular light exercise programs to maintain proper strength and mobility of your new knee.
Take special precautions to avoid falls and injuries. If you break a bone in your leg, you may require more surgery.
Make sure your dentist knows that you have a knee replacement. Talk with your orthopedic surgeon about whether you need to take antibiotics prior to dental procedures.
See your orthopedic surgeon regularly for a routine follow-up examination and x-rays, usually once a year.

Extending the life of your replacement

Currently, more than 90% of modern total knee replacements are still functioning well 15 years after the surgery. Following your orthopedic surgeon's instructions after surgery and taking care to protect your knee replacement and your general health are important ways you can contribute to the final success of your surgery.