The knee joint is one of the most important joints in the human body. It is extremely important for walking, walking up and down stairs, and sitting. It also carries the weight of the body when standing. If you have knee pain or movement disorder, your doctor may initially give you oral medication, injection therapy, massage and physical therapy after examining and judging the knee joint. If the results are not satisfactory after all of these treatments, you should discuss with your doctor to see if an artificial knee replacement is necessary. What is artificial knee replacement surgery?
When the normal anatomy of the knee is severely damaged and the knee joint cannot function normally, i.e., it is painful to move, the surgeon surgically removes the damaged joint and replaces it with a precisely designed and manufactured artificial knee joint.
The normal knee joint in the human body is made up of three bones. The lower part of the thigh bone (femur) forms the upper part of the knee joint; the upper part of the main bone of the lower leg (tibia) forms the lower part of the knee joint; and a small, slightly flattened bone (patella) forms the front part of the knee joint. All the bones that make up the knee joint are covered with a few millimeters of smooth, mirror-like, slightly elastic, painless cartilage (articular cartilage), called the articular surface. In the knee joint, the femur and tibia form a pair of joints, and between the articular surface of the femur and the articular surface of the tibia, there is a half-moon shaped piece of fibrocartilage (meniscus) that acts as a cushion between the femur and the tibia. The lower end of the femur is in front of the patella and forms a pair of joints. These bones are also surrounded by muscular ligaments. All of these structures together make up the knee joint. The normal knee joint, through the action of the muscular ligaments, allows for smooth, smooth, even, painless movement of the joint surfaces, while ensuring effective joint stability. If the joint surface is worn, defective or damaged for various reasons, it often causes painful walking and dysfunction.
The most common factors leading to knee pain and limited motion are osteoarthritis, rheumatoid arthritis and traumatic arthritis.
Osteoarthritis: commonly occurs after the age of 50 and often has a family history of arthritis. In this type of arthritis, the articular cartilage and meniscus that serve as a cushion have often worn away and the joint space has become smaller, resulting in painful friction, joint deformity and stiffness.
Rheumatoid arthritis: It can cause inflammation of the synovial lining of the joints, producing excessive joint fluid; inflammation can also erode and destroy joint cartilage, causing joint pain, deformity and stiffness.
Traumatic arthritis: Intra-articular fractures can directly damage the articular cartilage.
The material of the artificial knee joint polyethylene liner tibial prosthesis femoral prosthesis artificial knee joint is designed on the basis of extremely advanced metallurgy, biomaterial science, biomechanics and bone surgery. It consists of three components. One is the femoral prosthesis, which is made of a smooth, wear-resistant alloy that fits tightly and firmly into the lower end of the femur after a special osteotomy to form the femoral articular surface; the other is the tibial prosthesis, which consists of two parts, one is a very wear-resistant and smooth ultra-high polymer polyethylene articular surface, which is held in place by a precision metal disc with a stem that can be inserted into the bone marrow cavity at the upper end of the lower leg bone (tibia) The stalk of the metal tray can be inserted into the bone marrow cavity of the upper end of the calf bone (tibia) and bonded to the bone; then there is a patellar prosthesis, which is disc-shaped and composed of ultra-high polymer polyethylene, which is to replace the patellar articular surface and bonded to the patella. There are two general methods of bonding, one is to use bone cement (an organic compound) to bond the prosthesis to the bone tissue, and the other is a special treatment of the metal surface into which the human bone will grow tightly to hold it in place. Most doctors today usually choose cemented fixation.
What is a unicondylar replacement?
A unicondylar replacement is a special type of artificial knee replacement that is limited to the unicondyle.
So what is a unicondylar? Based on the shape and function of the knee joint, we divide the knee into two parts: the medial and lateral. The medial one consists of the medial femoral condyle, the medial meniscus and the lateral tibial plateau. Similarly, the lateral portion consists of the lateral femoral condyle and lateral meniscus and the lateral tibial plateau. The medial and lateral condyles of the knee are different in shape and do not function in exactly the same way. Generally the medial condyle is under more pressure and the lateral condyle has more rotational function. Therefore, as people get older, decades of wear and tear often damage the cartilage of the medial condyle of the knee first, exposing the bone and eventually causing the typical osteoarthritis, which is when the bones rub against each other, causing pain and swelling in the joint and making it difficult to walk.
Since only the medial condyle of the knee joint is worn out and the lateral condyle is still intact, only the aging wear of the medial condyle needs to be treated, resulting in unicondylar replacement surgery. There are many unicondylar artificial joints abroad. This joint retains the lateral condyle, patella, cruciate ligament and other structures, so the patient’s knee function is basically normal without the discomfort caused by total knee replacement. The trauma is minimal, with the wound being half that of a traditional total knee replacement, and the patient recovers quickly and at a low cost.
Should I have an artificial total knee replacement or a unicondylar replacement?
The decision must be made after consultation with yourself, your family and your orthopedic surgeon. Common conditions that require knee replacement surgery are
Severe pain in the knee that limits your daily activities, such as walking, going up and down stairs, or walking a few blocks, and you need the help of a walker or cane; pain when you are resting during the day or at night; inflammation and edema in the knee that does not improve with rest or medication; deformity of the knee, such as an O-leg or X-leg; the knee feels stiff and is difficult to extend and flex; non-steroidal anti-inflammatory drugs have not worked The knee is stiff and has difficulty extending and flexing; non-steroidal anti-inflammatory drugs such as anti-inflammatory pain and ibuprofen are ineffective; pain medications have serious side effects; physical therapy, hormone injections and other surgical treatments are ineffective.
Most people who need surgery are between 60 and 80 years old, but doctors make different decisions depending on the individual. The recommendation for surgery depends on the patient’s pain and pathology, not just on age, and a successful total knee replacement can be achieved in a young person such as 16 years old or an older person such as over 90 years old.
The orthopedic evaluation necessary before deciding to have an artificial joint replacement surgery includes the following tens of thousands of aspects.
History: The doctor gathers information from asking about your general health, the degree of knee pain and how it affects your daily life, etc.; physical examination to determine the mobility and alignment of your knee, etc.; x-rays to examine the extent of damage and deformity of your knee; and sometimes blood tests or other tests such as MRI, bone scan, etc. to examine the bone structure and soft tissue of your knee; your Based on this information and evaluation, your orthopedic surgeon will discuss with you whether you need an artificial knee replacement to eliminate pain and improve function, or whether other methods of treatment, such as medication, physical therapy or other types of surgery, may be considered. Although very low, they are difficult to eliminate. Expectations for total knee replacement are that the vast majority of patients will experience a significant reduction in knee pain, significant improvement in function, self-management of daily activities, and an improved quality of life after surgery, but the surgery will not result in better knee function than before.
After surgery, there are certain things that you will be prohibited from doing for the rest of your life, including jogging and high impact sports. The artificial knee will wear a little on its plastic pad even with regular activity; excessive activity and weight bearing will accelerate the wear, resulting in loosening of the prosthesis and knee pain; if used correctly, the artificial knee will last for many years, more than 90% of patients can keep it for more than 10 years.
Dangerous activities after surgery: including running or galloping, contact sports, jumping sports, strenuous aerobic exercises, etc.