1.What is artificial knee joint replacement
The so-called artificial knee joint replacement, also known as knee surface replacement, commonly known as “knee replacement” in Guangdong, is similar to the dentist installing braces on the surface of broken teeth, using artificial biological materials to make a prosthetic joint to replace the diseased knee cartilage through precise surgery, thereby eliminating pain, improving the function of the knee joint The goal is to eliminate pain, improve knee function, correct deformity, and improve quality of life. After surgery, not only is the limb intact, but all the structures of the knee joint are preserved except for the removal of the damaged cartilage, meniscus, anterior or posterior cruciate ligaments, which is wrong to equate “knee replacement” with “installation of a prosthesis”. This is due to the lack of medical knowledge.
2. What are the indications for artificial knee arthroplasty?
The correct selection of surgical indications is the primary factor affecting clinical outcomes. Artificial knee arthroplasty is mainly used for patients who have severe joint pain, instability, deformity, and serious impairment in daily life, and for whom conservative treatment is ineffective or ineffective. These include various inflammatory arthritis of the knee joint, such as osteoarthritis, rheumatoid arthritis, ankylosing spondylitis involving the knee joint, hemophilic arthritis, etc.; traumatic arthritis; osteoarthritis after failed high tibial osteotomy; resting infectious arthritis (including tuberculosis); severe osteonecrosis of the knee joint, knee joint pigmented villous nodular synovitis, knee synovial chondromatosis, etc. In addition to the severity of the disease itself, age, occupation, personal values, and economic status should also be taken into account. For some very young patients, knee fusion still has a recommended value. In contrast, for neuropathic (Charcot) arthritis is currently classified as a relative contraindication.
3. What are the contraindications to artificial knee arthroplasty?
Any active infection of the body and local joints; paralysis of the muscles around the knee joint; severe vascular lesions of the lower extremities; immature skeletal development; poor condition of the soft tissues around the knee joint; the knee joint has been fused and fixed in a functional position (extension or mild flexion) for a long time without symptoms such as pain and deformity.
4. What are the long-term results of artificial knee replacement?
Artificial knee replacement has been used clinically for more than 40 years and is one of the most successful surgical procedures of the 20th century, with more than 600,000 patients worldwide gaining an improved quality of life each year. The artificial knee joint is made of metal and polymer plastic, following the shape of the human joint. These materials have undergone rigorous laboratory testing and are safe and reliable. It can be used for more than 20 years in 80% of patients who are elderly with little movement. Of course, the service life of artificial joints also has a lot to do with the skill level of the doctor. Experienced doctors install joints of the right size, accurate position and tight fit, and the joints will naturally last longer. The next factor is the post-operative rehabilitation, as well as the patient’s weight, activity level, and the presence of problems with the other leg.
5. What are the possible complications of artificial knee arthroplasty?
Although artificial knee arthroplasty is a highly successful surgery and the chance of complications is not high, it is important to have sufficient knowledge of the possible complications so that both doctors and patients can cooperate fully in an effort to minimize the incidence.
(1) Thromboembolism: Without any prophylaxis after artificial knee replacement, the chance of thromboembolism increases significantly, reaching 40% to 84%, with proximal thrombosis above the N vein occurring in 9% to 20% of patients, and the risk of life-threatening pulmonary embolism is greater than that of calf vein thrombosis. The occurrence of thromboembolism is influenced by many factors, including direct factors such as surgical trauma, intraoperative tourniquet use, and reduced postoperative lower extremity motion. Risk factors include age over 40 years, estrogen use, stroke, nephrotic syndrome, cancer, history of thromboembolism, prolonged braking, congestive heart disease, built-in femoral vein, enterocolitis, obesity, varicose veins, smoking, high stress, diabetes, and coronary artery disease. The possibility of thrombosis should be considered if there is progressive painful swelling in the calves and thighs. The prevention methods include: mechanical prevention and drug prevention, and there is a distinction between Chinese medicine and western medicine. Mechanical methods such as wearing elastic stockings and applying lower limb venous pumps to promote venous return. Despite all these preventive measures, thrombosis may still occur. If you still have ongoing pain or redness in your lower extremities after surgery, you should contact your surgeon promptly.
(2) Loosening of the prosthesis: The prosthesis may loosen within the fixed bone after the artificial knee replacement. This condition has the potential to cause pain. Once loosening of the prosthesis is diagnosed, revision surgery is required. Various solutions have been developed for the revision of aseptic loosening of the artificial knee joint with good results.
(3) Infection: Infection after artificial knee replacement, especially deep infection, is a catastrophic complication with a slightly higher incidence than in artificial hip replacement, (between 1,6% and 2,6%). Infection can occur on the surface of the wound or deep; it can occur early (within 4 weeks postoperatively) or late (after 4 weeks postoperatively). Except for infections that occur superficially and a few early infections that can be controlled by local surgical management and the application of antibiotics, most require revision surgery by removing all or part of the prosthesis. Therefore, it is expected that the patient should take the initiative to tell the surgeon about any infected lesions in any part of the body before surgery so that the surgeon can grasp the timing of the surgery, while once the postoperative redness and pain around the wound occurs, the surgeon needs to be contacted promptly to rule out the infection or deal with it promptly. Also for some atypical postoperative knee replacement infection diagnosis is still difficult and requires a physician with extensive experience. The success rate of standardized revision surgery for infected artificial knee joints has reached about 90%.
(4) Dislocation: a relatively uncommon complication after artificial knee arthroplasty that requires revision surgery to address the specific cause.
(5) Prosthetic fracture: Fractures of metal and polyethylene prostheses are relatively rare, some are due to product quality, some are due to surgical installation techniques, and some are related to improper patient use. Once it occurs, a revision surgery must be performed to replace the prosthesis.
(7) Nerve injury: rarely occurs, mostly in patients with severe valgus deformity, with the correction of the valgus deformity, coupled with postoperative bandaging too tight, the common peroneal nerve is prone to stretching, compression injury, such as the rapid release of compression most can be partially or completely recovered, but if the nerve rupture recovery is more difficult, need to take appropriate remedial measures.
(8) Vascular injury: rarely occurs, mostly related to anatomical abnormalities or improper surgical operation, and needs to be treated immediately once found to avoid ischemic necrosis of the limb.
(9) Knee extension or flexion disorders: Many factors can cause knee extension or flexion disorders after artificial knee replacement, among which factors of knee disease itself, surgical technique, and postoperative rehabilitation are the most important ones. For patients with common osteoarthritis, most knees can be fully straightened and flexed to 115 degrees or even greater after surgery if their preoperative extension and flexion functions are basically normal, and they can meet their daily life and social needs, including performing household chores, going up and down stairs, traveling, hiking, climbing, cycling, ballroom dancing, etc. The acquisition of these functions is the result of the joint efforts of the doctor, the patient, and the rehabilitator, all three of which are indispensable. Of course not every patient achieves perfect function, and some activities such as deep squatting are not suitable for obese elderly people over 70 years old, obtaining a range of motion from 0 to 90° is fine and relatively easy to achieve.
6.How do I choose an artificial knee prosthesis?
There are many professional companies that produce artificial knee prostheses, and each company has different types of knee prostheses, so there are a wide variety of knee joints available, which can be roughly divided into CR knee prostheses that retain the posterior cruciate ligament and PS knee prostheses that do not retain the posterior cruciate ligament, both of which are suitable for patients with initial knee replacements. Depending on whether the prosthetic spacer is mobile or not, there are movable spacer and fixed spacer knee prostheses. Depending on the flexion angle of the prosthesis design, there are high flexion prostheses and normal prostheses. to meet different patient requirements. The choice of knee prosthesis should be mutually agreed upon by the physician and the patient according to the condition and the patient’s financial ability.
7. What is the cost of knee replacement? How long does the hospital stay take?
Depending on the type of artificial joint used, the cost (including all costs for artificial joint materials, surgery, medications and tests, hospitalization, etc.) varies. In our hospital, the cost of a unilateral knee replacement is about $40,000 to $80,000 for an imported joint prosthesis, and about $30,000 to $50,000 for a hospital stay for a unilateral knee replacement with a domestic joint prosthesis. If the patient requires a higher quality of life after surgery or requires a special type of prosthesis due to factors of the condition, the hospitalization cost will also increase.
After hospitalization, the first step is to fully examine your body, evaluate the function of your heart and lungs and other major organs, and develop a surgical plan, which usually takes 2 to 3 days. If you recover well after surgery, you can be discharged to a rehabilitation center or go home for functional exercises after 1 week, so that the total hospital stay is about 10 days.
8. How to rehabilitate after the artificial knee joint replacement?
The planned rehabilitation exercises after total knee arthroplasty can improve joint function, correct joint deformity and relieve pain to the maximum extent. Immediately after surgery, you can start to practice ankle flexion and extension activities; after anesthesia wears off, you can perform isometric contractions of the quadriceps and N cord muscles and ankle flexion and extension activities for 5 to 10 minutes every hour to promote blood circulation and prevent thrombosis. 2~3 days after surgery, start to practice standing and walking with crutches; 4-14 days after surgery, continue functional exercise, and at the same time, strengthen the knee flexion and extension range of motion exercise: bedside and bedside knee flexion and extension exercise, bedside knee flexion and extension exercise, and bedside standing and squatting exercise. Use crutches to practice walking and strengthen gait walking training, etc. 2-6 weeks after surgery, continue the above functional exercises, and gradually increase the time and frequency of exercises. Gradually remove walking from crutches and practice walking up and down stairs. After complete recovery, appropriate physical activities can be carried out, but in daily life, pay attention to maintain the appropriate weight, prevent osteoporosis, avoid too much strenuous exercise, do not do strenuous jumping and rapid stop and turn movement.
9. Do I need regular review after surgery?
It is recommended to return to the hospital 2 to 4 weeks after discharge, so that the surgeon can keep abreast of the recovery of the knee wound, the improvement of the pain, and especially the improvement of the knee movement, which will help guide the patient to better recovery and improve the surgical effect and prolong the life of the prosthesis. During the review, it is necessary to record the improvement of clinical symptoms, measure the joint movement angle, perform necessary imaging examinations, register the joint scoring scale (HSS score of knee joint, WOMAC health questionnaire), etc.
10. What is the role of Chinese medicine techniques in artificial knee arthroplasty?
Chinese medicine techniques include Chinese herbal medicine (internal and external), acupuncture, massage, etc. The role of Chinese medicine techniques in artificial knee arthroplasty is mainly reflected in two aspects: First, the application of blood-stasis activating Chinese medicine after surgery can effectively reduce the complications of thromboembolism and reduce the side effects of western anticoagulants; second, massage, massage and external fumigation of Chinese medicine can help reduce postoperative pain, improve the range of motion of the knee joint and improve the overall effect of surgery. Second, massage, massage, and topical fumigation with Chinese herbs can help reduce postoperative pain, improve the range of motion of the knee joint, and enhance the overall effect of surgery.