The knee is one of the most important joints in the human body, and it is extremely important for walking, walking up and down stairs, and getting up and sitting down. It also carries the weight of the body when standing. If you have knee pain or mobility problems, your doctor may initially give you oral medication, injection therapy, massage and physical therapy after examining your knee. If after all these treatments, the results are still unsatisfactory, it is time to look into the need for artificial knee replacement surgery. What is artificial knee replacement surgery? When the knee joint cannot perform its normal function due to severe damage to its normal anatomy, i.e., it is painful to move around, the surgeon surgically removes the damaged joint and replaces it with a precision-designed and manufactured artificial knee joint, which is called an artificial knee replacement. The normal knee joint of the human body The knee joint consists of three bones. The lower end of the thigh bone (femur) makes up the upper part of the knee joint; the upper end of the main bone of the lower leg (tibia) makes up the lower part of the knee joint; and a small, slightly rounded bone (patella) makes up the front part of the knee joint. All of the bones that make up the knee joint are covered with a layer of smooth, mirror-like, slightly flexible, painless cartilage (articular cartilage) a few millimeters thick at the point where they rub against each other, called the articular surface. In the knee joint, the femur and tibia form a pair of joints, between the femur joint surface and tibia joint surface, there is also a half-moon shaped piece of fibrous cartilage tissue (meniscus), which plays a cushioning role between the femur and tibia. The lower front of the femur in turn forms a pair of joints with the patella. These bones are 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 smooth, smooth, even and painless movement of its articular surfaces, while at the same time ensuring effective joint stability. If the articular surfaces become worn, defective or damaged for any reason, walking pain and dysfunction often result. Common factors causing knee pain and limited movement The most common are osteoarthritis, rheumatoid arthritis and traumatic arthritis. Osteoarthritis: It is common 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 liner have often worn away and the joint space becomes smaller, leading to painful friction, joint deformity and stiffness. Rheumatoid arthritis: It can lead to inflammation of the synovial joints, producing excessive joint fluid; the inflammation also erodes and destroys the articular cartilage, causing joint pain, deformity and stiffness. Traumatic arthritis: intra-articular fractures can directly destroy articular cartilage. Materials of artificial knee joint 1.Polyethylene liner 2.Tibial prosthesis 3.Femoral prosthesis The artificial knee joint is designed on the basis of extremely advanced metallurgy, biomaterials, biomechanics and bone surgery. It consists of three components. One is the femoral prosthesis, which is made of smooth and wear-resistant alloy, and can be closely and firmly combined with the lower end of the femur after special osteotomy, constituting the femoral joint surface; the other is the tibial prosthesis, which consists of two parts, one of which is a layer of very wear-resistant and smooth ultra-high polymer polyethylene made of the articulating surface, and there is a precision metal plate with a handle under it, and the handle of the metal plate can be inserted into the bone marrow cavity at the upper end of the calcaneus bone (tibia) and closely combined with bone; and then there is an artificial knee joint which is made of very advanced metallurgy, biomaterials and biomechanics, and bone surgery. The shank of the metal tray can be inserted into the bone marrow cavity of the upper end of the lower leg bone (tibia) to be tightly combined with the bone; and then there is a patellar prosthesis, which is made of ultra-high polymer polyethylene in the shape of a disk, which has to replace the patellar articular surface to be tightly combined with the patella. There are two methods of bonding generally used, one is to use bone cement (an organic compound) to bond the prosthesis with the bone tissue, and the other is to provide a special treatment to the metal surface, the human bone will grow into it closely to fix it. Most doctors nowadays usually use cement to fixate the prosthesis. What is a unicondylar replacement? A unicondylar replacement is a special type of artificial knee replacement, one that is limited to one condyle. So what is a unicondylar? According to the shape and function of the knee joint, we divide the knee joint into inner and outer parts. The inner one consists of the medial femoral condyle, the medial meniscus and the lateral tibial plateau. Similarly, the lateral part consists of the lateral femoral condyle and lateral meniscus and the lateral tibial plateau. The medial and lateral condyles of the human knee have different shapes 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, when a person grows old, decades of wear and tear often damage the cartilage of the medial condyle of the knee joint first, exposing the bone, and finally causing typical osteoarthritis, which means that the bones rub against each other, resulting in joint pain and swelling, and difficulty walking. Since only the medial condyle of the knee is worn out and the lateral condyle is still intact, only the aging wear and tear of the medial condyle needs to be treated, and the surgery of unicondylar replacement is available. There are many unicondylar artificial joints abroad. This type of 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 small, the wound is only half of the traditional total knee replacement, the patient recovers quickly and the cost is low. Should I have an artificial total knee replacement or a unicondylar replacement? The decision must be made in consultation with you, your family and your orthopedic surgeon. Common conditions that require knee replacement surgery are: 1. Severe knee pain 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; 2. Pain that you experience during the day or at night when you are resting; 3. Inflammation and edema of the knee that does not improve with rest or medication; 4. Deformities of the knee such as an O- or X-shaped leg; and 5. The knee feels strong and hard, and it is difficult to extend or flex; 6. The use of non-steroidal anti-inflammatory drugs is ineffective, such as anti-inflammatory pain, ibuprofen, etc.; 7. Painkillers have serious side-effects; 8. Physiotherapy, hormone injections and other surgical treatments are ineffective. 9. Most people who need surgery are between 60 and 80 years old, but doctors have to make different decisions for different individuals. The recommendation for surgery depends mainly on the patient’s pain and lesions, not only on age, and it is possible to get a successful total knee replacement if you are young, such as 16 years old, or old, such as over 90 years old. Necessary tests before deciding to have an artificial joint replacement Orthopaedic evaluation includes the following aspects: Medical history: the doctor collects information from inquiring about your general health, the degree of pain in your knee and how it affects your daily life, etc.; a physical examination is performed to determine the mobility and alignment of your knee, etc.; X-rays are taken to check for the extent of the damage to and deformity of your knee; and in some cases, blood or other tests, such as MRI, bone scans, etc., are performed to check for the degree of damage and deformity of your knee. Sometimes blood tests or other tests, such as magnetic resonance imaging (MRI) or bone scans, are also used to examine the bone structure and soft tissues of your knee. Based on this information and evaluation, your orthopaedic surgeon will discuss with you the need for an artificial knee replacement to eliminate pain and improve function, and will also consider whether to treat the problem with other methods, such as medication, physical therapy, or other types of surgeries; your surgeon will also explain the possible complications and potential risk factors of a total knee replacement. Your doctor will also explain to you the possible complications of total knee replacement surgery and the potential risk factors, which have a chance of occurring in about 1%, and which, although low, are difficult to eliminate. They will be mentioned later in this brochure. What to Expect from Total Knee Replacement The vast majority of patients experience a significant reduction in knee pain, a marked improvement in function, the ability to manage their daily activities, and an improved quality of life after surgery, but surgery does not make the knee function any better than it did before the disease. After surgery, there are some things that you will not be able to do for the rest of your life, including jogging and high-impact sports. The artificial knee will wear a little on its plastic cushion with regular activity; excessive activity and weight bearing will accelerate the wear and tear to the point where the prosthesis loosens and knee pain occurs; if used correctly, the artificial knee will last for many years, with more than 90% of patients retaining their knee for more than 10 years. Risky activities after surgery: These include running or running, contact sports, jumping, strenuous aerobic exercise, etc.