Hip osteoarthropathy is one of the common diseases of hip, including rheumatoid arthritis, ischemic necrosis of the femoral head, ankylosing spondylitis, especially rheumatoid arthritis, ischemic necrosis of the femoral head, and in the late stage, most of them are accompanied by fibrous and bony contracture ankylosis of the hip joints bilaterally and pain, which seriously affects the patient’s life and work, and even the patient can not live by himself/herself. Artificial hip arthroplasty is a mature and satisfactory orthopedic surgery for the treatment of hip joint diseases. However, for some patients with simultaneous development of both hips, which seriously affects walking and daily life, and considering that it is very difficult to rehabilitate the joint function after unilateral total joint replacement, from April 2002 to December 2006, we used simultaneous bilateral artificial total hip arthroplasty to treat 18 cases of patients with obvious pain and difficulty in walking caused by bilateral hip joint lesions, and the efficacy of the surgery is reported as follows. Satisfactory, reported as follows. 1, clinical information 1, 1 general information: this group of 18 cases (36 hips), 12 men, 6 women. Age 45-72 years old, the average age of 54, 6 years old. 8 cases have a history of alcohol consumption, 6 cases have a history of hormone use, 2 cases of rheumatoid arthritis, ankylosing spondylitis caused by bilateral hip ankylosis in 1 case, 1 case of no obvious cause can be found. All of them had obvious pain in the hip joint before surgery, with limited activities, affecting walking and seriously affecting work and daily life. The difference in length of bilateral limbs before surgery was 1,2-4,5 cm, and the average Harris score was 42,3 (33-59 points). The time from the appearance of clinical symptoms to undergoing surgery was within 1 year in 1 case, 1-2 years in 3 cases, 2-3 years in 5 cases, and more than 3 years in 9 cases. 1, 2 preoperative preparation: ① routine preoperative blood routine, blood sedimentation, C reflective protein, coagulation time, urine routine, blood biochemistry, electrocardiogram, abdominal ultrasound, chest radiographs, etc., preoperative preparation of 600-1000 ml of blood. ② preoperative check the proportion of pelvic X-ray film, including the upper femur, if necessary, double hip CT examination, a full understanding of the femoral head and acetabular pathology, and the initial selection of the appropriate The preliminary selection of the appropriate artificial prosthesis. Postoperative infection around the prosthesis can be disastrous for joint replacement. In the preoperative period, actively treat infectious diseases and potential foci of infection, such as lung infections, urinary tract infections, boils and carbuncles. Postoperative routine nebulization suction to facilitate sputum coughing out, and early removal of urinary catheter. ④ Start applying broad antibiotics 2d before operation, and give the drug once an hour before operation to maintain the concentration of antibiotics during operation. ⑤Control systemic diseases that are easy to lead to infection, such as diabetes mellitus, make sure to control blood glucose at about 6-7mmol/L before surgery, and monitor blood glucose closely after surgery. 1,3 Surgical method: continuous epidural anesthesia or tracheal intubation general anesthesia is used, and 90° ortholateral lying position is taken. Surgery took the posterior lateral incision of the hip joint manway. Taking the apex of the greater trochanter as a marker, an arc-shaped incision of about 12 cm was made, and the skin, gluteus maximus fascia were incised along the direction of the incision to reveal the pyriformis and external rotator muscles, partially cut off the external rotator muscles, and the joint capsule was incised in an arc shape and protected. Intraoperatively, there is no need to visualize the lesser trochanter. The length of the preserved femoral spur is determined by palpation, and the femoral neck is sawn to remove the femoral head. The diseased synovial tissue and the inner part of the hyperplastic and hypertrophic joint capsule are completely removed. The acetabulum is exposed with special instruments without removing the labrum and capsule, only the remnants of the round ligament are removed, and the acetabulum is filed with an acetabular file step by step until the subchondral bone is uniformly bleeding in spots, but an anterior tilt angle of 15°±10° and an abduction angle of 45°±10° should always be maintained. A non-cemented acetabular prosthesis 2 mm larger than the size of the acetabular file is selected. The patient flexes the hip and knee and internally rotates, elevates the proximal femur to expand the medulla oblongata, if the patient is younger and has good bone mass choose and install the non-cemented bone long into the type of prosthesis, older patients with poor bone mass choose the cemented femoral stem prosthesis , try the mold and install the femoral head prosthesis. Adjust the length of bilateral limbs, reset the artificial joint after flexion of the hip and knee > 90 °, internal and external rotation are 45 ° without dislocation, the joint cavity built-in negative pressure drainage tube, suture the joint capsule and lateral femoral muscle, etc., close the incision. Change to the contralateral 90 ° lateral position, the same method for the contralateral THA. 1,4 postoperative treatment: ① lying double lower limbs elevated abduction neutral position, feet wearing anti-rotation shoes. ② Remove the drainage tube 2-4 days after surgery; remove the incision suture 12-16 days. (iii) Start to perform isometric stretching activities of quadriceps and gastrocnemius muscles on the first day after surgery, and start to perform alternating active hip flexion and knee flexion exercises of both lower limbs in the abducted neutral position on the second day, and start to bend the hip by 15-20°, and increase the hip flexion by 20° to 90° every day. ④ On average, sit up and move the upper body in 6-12 days after operation, exercise both lower legs hanging down the edge of the bed in 9-18 days, assist in moving down to the ground with the help of crutches in 12-30 days, and don’t do complete squatting and cross-legged movement in 3 months. ⑤ Apply broad antibiotics for 5-7 d. Postoperative hemostatic drugs are forbidden, and apply blood-activating and blood-sludging traditional Chinese medicine for 10-14 days. ⑥Sacro-caudal, scapular and heel bone protrusions with soft pads are massaged regularly to prevent pressure from developing decubitus ulcers. (7) Encourage deep inhalation and nebulized inhalation to assist sputum expulsion in patients with sputum expulsion difficulties. 2, results of all cases are a phase of bilateral total hip arthroplasty, the operation time of 3,5 ~ 5,1h, average 4,4h. intraoperative bleeding 600 ~ l100ml, average 780ml. intraoperative blood transfusion of 600 ~ 1000 ml, average 720ml. 2 ~ 4d after the operation are taken pelvic plain film shows that the artificial prosthesis is placed in a good position (Fig. 1, Fig. 2). Figure 1 Preoperative radiographs of bilateral humeral head necrosis Figure 2 Postoperative radiographs of bilateral total hip arthroplasty There was no intraoperative vascular or neurological injury in all cases, and the incision healed in one stage. one case developed deep vein thrombosis of the left lower extremity on the 9th day after surgery, and the swelling subsided after two weeks of elevation of the affected limb and timely anticoagulation treatment with elastic stockings. After an average of 21 months of follow-up (4-59 months), there was no case of hip dislocation, no joint infection, and the difference in the length of both lower limbs was 0-9mm without claudication. 2 cases had mild pain in the hip at 3-6 months after surgery, with no abnormality in biochemical examination, which was relieved after 9 months of symptomatic observation. One case was found to have heterotopic ossification above the greater trochanter in the X-ray examination 3 years after surgery, which was not affected by the joint movement and was not specially treated under temporary observation. The Harris score of joint function was 78-85 points, with an average of 82 points. No loosening of the prosthesis was found in the postoperative follow-up X-ray, and all of them resumed their daily life and low-intensity work. 3, Discussion Artificial total hip arthroplasty has fully demonstrated its superiority in relieving patients’ pain and improving joint function. At present, joint replacement is the only treatment method that can solve joint pain and restore joint function. Some patients with bilateral hip lesions need to perform bilateral artificial hip replacement, should be staged replacement or simultaneous replacement of different views, many people believe that simultaneous bilateral hip replacement will increase the risk of anesthesia surgery, or concerns about the simultaneous replacement of both hips will affect the patient’s early down to the ground, early functional exercise. Overseas scholars have concluded that simultaneous bilateral hip replacement is safe (1). Recently, domestic scholars have shown that bilateral hip replacement in 1 stage is superior to staged replacement(2). 3.1 Selection of cases: The cases in this group are all bilateral hip joint lesions, patients with bilateral hip pain, activity is obviously limited, seriously affecting the work and life, X-ray suggests that the bilateral hip lesions are similar, the femoral head is deformed, the joint space is narrowed or disappeared, and joint replacement is the only way of treatment. 3.2 Indications and contraindications: Hip joint lesions mostly occur in middle-aged and elderly people, who are relatively more likely to suffer from medical diseases. Although THA is a more mature and standardized surgery, the greater trauma is obvious. The literature reports a 1% mortality rate for stage I bilateral total hip replacement due to embolization and cardiopulmonary complications, which is 2 or 5 times higher than unilateral or split bilateral total hip replacement (3). We suggest that preoperative comprehensive assessment of the patient’s general condition, hepatic and renal function, cardiopulmonary function, and water and electrolyte balance should be made together with the relevant internist and anesthesiologist to clarify whether the patient can tolerate anesthesia and stage I bilateral THA. Simultaneous replacement of bilateral artificial joints has greater intramedullary interference and is more prone to inducing fat embolism (4), and if the patient has cardiopulmonary disorders preoperatively, fat embolism can lead to the patient’s condition being Aggravation. Therefore, risk prediction should be made for each patient, and in the case of one-stage bilateral THA, the following two conditions should be changed to split bilateral THA: (1) severe arrhythmia, acute myocardial infarction, and heart failure. Pulmonary insufficiency or uncontrolled pulmonary infection. ③ Liver insufficiency, combined with splenomegaly and ascites. ④ Severe diabetes mellitus or ketoacidosis, blood glucose is still greater than 15mmol/l after active medical treatment ⑤ During surgery after THA has been performed on one side, the patient develops cardiorespiratory dysfunction, decrease in partial pressure of oxygen, decrease in blood pressure, persistent increase in heart rate, and significant increase in bleeding, then the other side of the surgery is stopped. At the same time the combination of arterial duct failure and heart valve defects are absolute contraindications. 3,3 The use of cemented or uncemented prosthesis is still controversial in academia. We believe that the use of cemented prosthesis is still a good method, especially for older patients with severe osteoporosis and widened medullary cavity, and it is important to further improve the cemented fixation technique. For younger patients with better bone quality to use non-cemented biological fixation is appropriate. 4.Preventive treatment of surgical complications: Deep vein thrombosis is also one of the complications that are easy to occur after hip arthroplasty, according to the literature, it is reported to be in 40-70%, and 2% of them can be serious pulmonary embolism(5), which is mainly manifested as the swelling of the affected limb and the pressure and pain of the muscles of the posterior side of the calf. In our group, there is a patient with postoperative venous thrombosis, after elevation of the affected limb, wearing compression stockings, small-dose heparin anticoagulation and active and passive exercise of the affected limb for 2 weeks, the swelling quickly subsided. This patient was sensitive to pain and did not cooperate with functional exercise. Patients with artificial joint replacement should be taught to perform muscle contraction exercises of the lower limbs before surgery, and after they are awake from anesthesia, they should be allowed to perform muscle contraction exercises on their own initiative, and wear elastic stockings with traditional Chinese medicines for activating blood circulation and removing blood stasis, which can effectively prevent the formation of venous thrombosis. Dislocation of prosthesis is an early complication of total hip arthroplasty. The key point of prevention: ① The prosthesis is installed in the correct position. Acetabular prosthesis abduction 45±1O angle, anterior tilt 15±5 angle; femoral prosthesis anterior tilt 5~1O angle. The incidence of dislocation is lowest in this position. ② It is crucial to clean up the hard tissues around the joint such as scar and bone redundancy, and protect the gluteus minimus muscle. ③Keep the artificial joint under some tension. ④ Repair the posterior extensor and abductor muscle groups at the back of the hip joint during surgery. ⑤ Postoperatively, the patient should be handled by specialized personnel, both lower limbs should be placed in the neutral position of abduction, rehabilitation training should be gradual, and squatting and cross-legged movements should not be done within 3 months. To summarize, bilateral total hip joint one-stage replacement for hip osteoarthropathy solves the lesions of 2 joints at the same time in one operation, relieves joint pain, and improves joint function significantly after operation. It not only saves time for the patient’s rehabilitation treatment and makes the postoperative joint function rehabilitation more convenient, but also avoids the long treatment course of unilateral replacement, the patient’s pain and the poor effect of postoperative functional exercise, and also reduces the risk of multiple surgeries and anaesthesia, and also reduces the patient’s psychological pressure and the economic burden. However, it is difficult to operate, and the indications for surgery should be strictly controlled. More attention should be paid to the prevention and treatment of complications. Only after detailed evaluation of the patient, adequate preoperative preparation, systemic and necessary auxiliary examinations, skillful mastery of surgical techniques and a team with tacit cooperation, and timely and correct guidance of the patient’s postoperative rehabilitation exercises can satisfactory results be achieved.