Artificial joints are artificial organs designed to save joints that have lost their function, thus relieving symptoms and improving function. Various artificial joints have been designed for many joints according to the characteristics of each joint in the body. Artificial joints are the most effective of the artificial organs. Modern artificial knee replacement surgery began in the 1960s, and after half a century of continuous development, it has become an effective method of treating advanced joint lesions, and is regarded as an important milestone in the history of orthopedic development in the twentieth century. Artificial knee replacement surgery is now a very mature technology. For those advanced knee diseases that are not effectively treated by conservative treatment or the effect is not significant, especially for osteoarthritis of the knee joint of the elderly, the surgery can effectively relieve the pain and improve the function of the knee joint, which can fully satisfy the needs of daily life, such as shopping, walking, doing housework, etc. It has become one of the common orthopedic surgeries. It has become one of the common surgeries in orthopedics. What kind of people can have artificial knee replacement? 1.Primary osteoarthritis, rheumatoid arthritis patients over 50 years old. 2.Secondary osteoarthritis, the joint has been destroyed, the function is seriously impaired, the condition has been stabilized. 3.Septic arthritis, tuberculous arthritis cured for more than 2 years, the knee joint is straight in non-functional position. What do I need to do before the artificial knee replacement surgery? 1.Good cardiopulmonary condition, able to tolerate the operation. 2.No tinea pedis and other infectious lesions in the limbs. 3.Pre-operative instruction to the patient to perform quadriceps functional exercise. 4. Take X-ray film of both knees in standing position before surgery, so as to measure the thickness of osteotomy according to the force line of lower limb and select artificial knee joints. 5. Apply antibiotics intravenously for two days before surgery. Artificial knee replacement surgery steps 1, the operation is often used in front of the knee in the middle of the longitudinal incision, starting from the patella above 6 ~ 10cm, down to the tibial tuberosity under 1 ~ 2cm. 2, cut the skin, subcutaneous tissue and deep fascia, in the subfascial direction on both sides of the free flap and pull open, revealing the quadriceps tendon, the patella and patellar ligament stop. 3, in the edge of the medial femoral muscle, the patella and patellar ligament stop point, and then the knee is cut to the knee. 3.Cut the quadriceps tendon at the edge of the medial femoral muscle, go down along the medial side of the patella, peel off the inner 1/3 of the patellar ligament stop, and turn the patella outward. 4, Remove part of the infrapatellar fat pad, meniscus and cut off the anterior cruciate ligament, excise the synovial membrane of the knee joint hyperplasia and the anterior bony encumbrance. 5.Then pull the tibia out of dislocation anteriorly, excise the remaining meniscus, and perform soft tissue release 1cm below the articular surface, medially to the inner posterior tibial angle (at 2 o’clock) and laterally to the middle (at 9 o’clock). For inversion deformities greater than 15°, the deeper layers of the medial collateral ligament and the goosefoot can be peeled under the periosteum and the tibial plateau hyperplasia can be excised. For severe inversion deformities, the semitendinosus muscle can be lengthened and loosened. For valgus deformity, the iliotibial bundle can be loosened at Gerdy′s node, and if further loosened, the lateral collateral ligament and N tendon can be lifted subperiosteally at the femoral stop with the knee flexed at 90°. If the knee flexion deformity is greater than 25°, the posterior capsule of the femur and tibia can be peeled off, and the posterior cruciate ligament can be cut off and the posterior stabilizing prosthesis and the posterior capsule can be cut off to complete the process. 6, femoral condylar osteotomy using intramedullary or extramedullary positioning, first in the intercondylar fossa of the femur after the anterior cruciate ligament 0.5 ~ 1.0 cm in the hole drilling and reaming inserted into the length of the T-shaped guiding rod should be through the isthmus of the femoral stem, to avoid the skew of the rod, and then mounted on the distal osteotomy guides, the installation of the standing alignment rod should be aligned with the center of the femoral head (anterior superior iliac spine inside the second finger). 7, the installation of osteotomies guiding board osteotomies, the thickness of the bone is usually osteotomies for 10 mm. Use the pendulum saw to amputate the excess bone of the distal femur to hold the condylar plate two rear claws close to the two posterior condyles of the femur to be placed and fixed, will be suitable for femoral condyles two-hole directional plate inserted in the holding condylar plate, the positioning plate is divided into the left and right, there are two kinds of neutral and externally rotated 3 ° position, holding the condylar plate on the measurement of the hook should be placed in the anterior lateral femur at the skin, tighten the knob, measure the appropriate size of femoral prosthesis type, through the femoral condyles directional holes to be drilled, and the installation of the corresponding size of the condyles multi-directional femur. Drill holes through the femoral condyle directional holes, install the corresponding size of the femoral condyle multidirectional osteotomy plate, and perform anterior and posterior condyle and oblique osteotomy. 8. Install the corresponding type of trolley bracket, and use the trolley grinding drill to grind out the cut marks. If the posterior stabilized prosthesis replacement is performed, the appropriate type of intercondylar fossa osteotomy frame can be fixed according to the top, and the intercondylar osteotomy is performed with bone knife and pendulum saw. 9. The tibia is pulled forward to semi-dislocation, and the holes are drilled at the stopping point of the anterior cruciate ligament and enlarged, and the intramedullary tibial directional rod is inserted, and the tibial osteotomy guides are installed in order to obtain the angle of backward tilt and the center of which is located at the inner 1/3 of the tibial tuberosity (marked by the American blue) to achieve the rotational alignment, and the osteotomy depth extractor, which is located in the guide, is installed on the guide. Installation of the osteotome to take the depth device, located in the lowest point of the tibial platform of the cavity on the side of the lesion is lighter, bone nail fixation platform osteotomy plate to take out the directional rod, the installation of the cutting frame and handle, the pendulum saw osteotomy. 10.Trimming platform proliferation of bone, tibial bone measuring board placed on the tibial platform after osteotomy to measure the size of the tibial platform. According to the measurement board measured size model, installation of the femur and tibia after the reset to measure the lower limb force line and rotational alignment. The thickness of the tibial pad was selected according to the degree of looseness and tightness. Punch in the tibial prosthesis shank file). Tibial prosthesis and femoral prosthesis number should be the same or a smaller number. 11, ectropion patella, trimming to remove the bony residue, measure the thickness of the patella (Figure 24), install the osteotomy guide fixator (Figure 25), according to the thickness of the patellar prosthesis, osteotomy thickness should be less than the thickness of the prosthesis of about 2mm, to determine the center of the patella should be slightly biased to the medial side, the patella fixation drill holes to the patellar measuring device to measure the size of the patellofemoral prosthesis (Figure 26). Install the patellar prosthesis trial mold, scarf pliers reset and fix the joint capsule, observe the patellar sliding trajectory, pay attention to the cut bone should not be too much, in order not to be lower than the patellar tendon as the limit. 12, remove the trial mold, rinse the wound, wipe dry. Make bone plugs into the femur and tibia drilled holes by cutting off the bone block and implant the prosthesis after adjusting the bone cement (Figure 27). The patella is fixed with a patellar compression device, and the excess bone cement is removed after the cement has cured, and the wound is rinsed to remove the excess cement and bone fragments. Drainage tubes were placed, the joint capsule was sutured with absorbable sutures, bandaged and immobilized, and the negative pressure suction device was pressed. Precautions for artificial knee replacement surgery 1, systemic application of antibiotics and drugs to prevent deep vein thrombosis. 2.Pressure bandage within 2 days after surgery, pay attention to the situation of incision drainage tube. 3, CPM exercise should be performed 2 days after surgery, and the patient should be encouraged to perform isometric exercise of quadriceps muscle. 4.Cement fixation patients walk on the ground with the help of crutches for 2 days.