Knee replacement surgery

It is very common to have pain or swelling in the bones and joints in daily life. When this happens to the bones and joints of the human body, especially when there is joint deformation or difficulty walking, it must be taken seriously. Usually, bone and joint replacement is the best choice. However, most people tend to resist after hearing about the operation, and many people do not know much about knee replacement surgery. What is knee replacement surgery?

Knee replacement surgery

The knee joint is an important weight-bearing joint of the lower limb, and its structure and function are the most complex among the joints in the human body. Degenerative osteoarthritis of the knee is a common disease among the elderly. It is reported that the incidence rate of symptomatic knee osteoarthritis in men over 50 years old is 35%, while that in women is as high as 74%. An increasing number of patients are suffering from severe knee osteoarthritis and require total knee replacement surgery. Knee replacement surgery can relieve knee pain, improve knee function, correct knee deformity and achieve long-term stability.

Preoperative preparation

1. General preparation: The patient undergoes routine blood, urine, stool examinations, blood biochemistry, blood coagulation, full set of blood transfusion tests, electrocardiogram, chest X-ray, B-ultrasound, etc.

2. Special preparation:

① Physical examination: Assess the condition of soft tissues: Is there any skin infection? Scar contracture? The range of motion of the knee joint, the tension of the medial and lateral collateral ligaments, whether there is valgus or valgus deformity, and the range of restricted joint motion.

② Color Doppler ultrasound of lower limb blood vessels. Because it is necessary to block blood flow to the lower limbs for a long time, the risks need to be assessed.

③X-rays: full-length weight-bearing lower limbs, lateral knee joint, and axial patellar views.

3. Select the size of the prosthesis based on preoperative X-ray measurements. Find out whether any medications you routinely take before surgery, such as aspirin or other nonsteroidal anti-inflammatory drugs, or long-term anticoagulants, need to be stopped before surgery.

4. Explain the purpose of the surgery to the patient and his family, enhance the patient's confidence in the surgery, and actively cooperate with the treatment.

5. Preoperative skin preparation, blood transfusion preparation, drug skin testing, etc. Do not eat or drink for 8 hours and 4 hours before surgery to prevent suffocation or aspiration pneumonia due to vomiting during surgery.

Surgical procedures

1. Incision exposure: In the past, the midline incision was the most commonly used. In addition, there are: parapatellar straight incision, medial parapatellar straight incision, lateral parapatellar straight incision, medial parapatellar small incision, medial parapatellar small incision, lateral knee joint approach, middle quadriceps approach, etc.

2. Release soft tissue: Perform corresponding release procedures for varus deformity, valgus deformity, and fixed contracture deformity.

3. Osteotomy: flexion-extension knee gap technique, joint line technique, and use of guides.

4. Manage the patella: maintain the correct position and movement trajectory.

5. Implant the prosthesis.

6. Place drainage and close the incision.

Postoperative Care

1. Antibiotics should be used for 7 to 10 days after surgery to prevent infection.

2. Lie flat without a pillow for 6 hours after the operation. Elevate the affected limb with a soft pillow and maintain a neutral position to avoid excessive compression of the gastrocnemius muscle and common peroneal nerve.

3. Fix the drainage tube to prevent it from being pulled, twisted, or folded to prevent it from falling off.

4. Observe the sensory activity of the affected limb, keep the ankle joint in a neutral position, and prevent foot drop.

5. Observe whether the limbs have swelling, and whether there are any abnormalities in the skin, temperature, color, and sensation of the extremities to prevent the occurrence of deep vein thrombosis.

6. Depending on the amount of drainage, the drainage is usually removed 48 hours after surgery, the sutures are removed 2 weeks later, and the patient is allowed to practice walking with crutches.