I. Do I need to have knee replacement surgery?
Due to various causes of knee joint pathology, resulting in serious impairment of knee function, long-term pain, difficulty walking, and dysfunction, which seriously affects the patient’s quality of life and has failed to improve with other conservative treatments, or there is no more effective treatment, knee replacement can be considered. Currently the most common causes are osteoarthritis of the knee in the elderly and rheumatoid knee arthritis in young and middle-aged people.
Second, what kind of surgery is knee replacement? How does it work?
Knee arthroplasty provides an effective treatment for end-stage knee pathologies and is becoming increasingly sophisticated, and has now become a routine procedure in joint surgery. In developed countries such as Europe and the United States, hundreds of thousands of knee replacements are performed each year. In China, since the entry of foreign artificial joints in the early 1990s, there has been a gradual increase in the number of artificial joints performed each year, reaching more than 100,000 cases.
Knee replacements have undergone decades of development and are becoming more and more mature. However, artificial joints are different from our own joints, especially because of the inevitable wear and tear and the lack of bioactive tissue’s unique ability to repair itself, so artificial knee joints have a lifespan, which depends on various factors such as prosthesis design, material performance, surgical technique, and patient condition. Generally speaking, knee replacement prosthesis can reach 80% to 90% after 15 to 20 years of use.
What are the requirements for knee replacement?
The main indications for artificial knee replacement are to relieve pain, deformity, walking difficulties and dysfunction caused by severe knee pathology.
1. Care should be taken to exclude radicular pain originating from spinal disorders, entrapment pain of the ipsilateral hip, peripheral vascular lesions, meniscal lesions and bursitis of the knee joint. Therefore, a detailed consultation with an experienced orthopedic specialist or joint surgery specialist must be sought to determine that the lesion is from the knee joint.
2. The presentation on the X-ray must be compatible with the clinical presentation of the knee lesion. Conservative treatment, including anti-inflammatory medications, physical therapy, and changes in activity patterns, should be actively pursued before considering surgical treatment for joint replacement.
3. Absolute contraindications to knee arthroplasty include: recent septic infection of the knee joint; discontinuity or severe loss of function of the knee extension device; retroflexion deformity secondary to muscle weakness and painless, well-functioning knee joint after fusion. Relative contraindications include poor general condition, severe cardiopulmonary, hepatic and renal disease, and significant arteriosclerosis in the affected limb. Again, a consultation with an expert in joint surgery, a comprehensive and detailed physical examination, and, if necessary, a thorough consideration of both the patient and the physician are required, within the limits of their abilities. In short, everything should be done with the patient’s life safety and improve the quality of life as the starting point.
4. Age: There is no absolute limit to the age of the patient for surgery. Currently, in clinical practice, the age of knee replacement patients is generally between 55 and 80 years old, with most between 65 and 78 years old. The main thing to look at is (1) whether it needs to be done? (2) the physical condition of the patient?
IV. What do I need to do before surgery?
As patients are mostly old and frail, their general condition should be fully evaluated in detail to ensure surgical safety. At the same time, a careful knee examination should be performed to assess the ligament and soft tissue, and to take front and side X-rays of the knee, axial X-rays of the patella, and full-length X-rays of the lower extremity in a standing position to understand the bone quality and force lines.
Diabetes, hypertension, coronary artery disease, rheumatoid disease and other diseases will bring risks to the surgery, therefore, it is necessary to give good assessment and control before surgery, and ask the relevant departments to consult and deal with them accordingly.
V. What does the knee joint replacement surgery do?
(1) Correct the deformity of the knee joint and restore the normal force line of the lower limb; (2) Restore the knee joint flexion and extension function; (3) Restore the knee joint pain-free walking function.
Specific surgical steps include: anterior median incision for the surgical approach, obtaining a balance of the medial and lateral soft tissues of the knee, reasonable osteotomy, selection of a suitable size prosthesis, correct placement of the femoral and tibial prosthesis, reasonable rotational positioning of the prosthesis, and a good patellofemoral trajectory. If there is a bone defect, it should be treated accordingly to the type of defect. Knee replacement is a technically demanding procedure that is closely related to the surgeon’s surgical experience, the number of surgeries performed each year, and the need for skilled surgical technique. It has been called “millimeter engineering”, meaning that a difference of 1 millimeter may cause a different result, which shows how delicate and precise the surgery is.
Specific surgical techniques include: (1) good lower limb force lines; (2) good soft tissue balancing techniques; (3) consistent flexion and extension gaps; (4) good patellar trajectory; (5) compliant osteotomy and prosthesis placement; and (6) strict aseptic techniques and minimally invasive concepts.
What to do after surgery?
1. Rehabilitation exercises.
Postoperative rehabilitation exercises have a great impact on the effect of artificial knee replacement, and reasonable postoperative rehabilitation guidance is important. Generally speaking, you can stand on the ground 2~3 days after surgery and gradually walk with a walker. At the same time, good postoperative analgesia is essential for smooth rehabilitation.
2. Prevention of complications.
The risk of potential complications of artificial knee arthroplasty includes: (1) venous thrombosis and pulmonary embolism; (2) infection; (3), patellofemoral joint complications; (4) vascular nerve complications; (5) periprosthetic fracture, etc. Adequate preoperative preparation, excellent surgical technique, and good postoperative management can minimize the risk of complications.
Since osteoarthritis of the knee is generally not life-threatening and does not require urgent surgery, adjusting the physical condition, controlling the various lesions, and consulting with an experienced specialist are the things that need to be done before surgery. Since many patients are elderly with chronic lesions, they need the cooperation of other departments for treatment. In order to ensure safety, it is recommended to go to a large hospital with a good reputation and strong general strength in joint surgery, which not only has specialized technology, but also has the cooperation and support of other strong disciplines, so that the surgery can obtain the expected results. From preoperative treatment, intraoperative techniques, postoperative management and rehabilitation, any negligence in any detail may affect the efficacy of the surgery and increase the risk of complications. Therefore, excellent surgical technique, careful and thorough perioperative management, and reasonable postoperative rehabilitation are the basis and basic requirements for a good outcome of knee replacement.