artificial femoral head replacement

DSA interventional therapy is one of the more novel methods for the treatment of femoral head necrosis. It uses a superb arterial intubation technique to directly inject the drug into the blood vessels supplying the femoral head, so that the blood vessels expand, sputum is relieved, and dissolved. Blocking the thrombus, thereby improving the blood supply of the femoral head, this treatment, if combined with other drugs, can provide a good basis for drug absorption. Treatment of diseases: femoral head necrosis femoral neck fracture Indication 1. The elderly over the age of 60, the head and neck fractures of the head, the displacement is obvious, and the healing is difficult. 2. Femoral neck subtotal comminuted fracture. 3. The old fracture of the femoral neck does not heal or the femoral neck has been absorbed. 4. Patients with femoral neck fractures that cannot be treated, such as hemiplegia, Parkinson's disease or mental patients. 5. Adult idiopathic or traumatic femoral head avascular necrosis has a large range, while acetabular injury is not heavy, and can not be repaired with other operations. 6. Benign tumors of the femoral neck should not be removed. 7. The primary or metastatic malignant tumor or pathological fracture of the femoral neck can be surgically replaced in order to alleviate the suffering of the patient. Contraindications 1. Old and frail, with serious heart and lung disease, can not tolerate the operator. 2. Severe diabetes patients. 3. Hip septic arthritis or osteomyelitis. 4. Hip joint tuberculosis. 5. Patients with severe acetabular destruction or significant acetabular degeneration. Preoperative preparation 1. Comprehensive physical examination, understanding the heart, lung, liver and kidney function, and appropriate treatment to adapt to surgery. 2. Patients with femoral neck fractures should be treated with preoperative skin traction or tibial tuberosity. The upward displacement of the distal end of the fracture and the contraction of the muscles around the hip should be corrected to reduce intraoperative and reduce postoperative complications. 3. Antibiotics are routinely given 1 to 3 days before surgery, and contraindications are given to the affected area to prevent infection. 4. Regular skin preparation for 3 days, night before the operation, and fasting 12 hours before surgery. 5. Select artificial femoral heads of similar size and place x-ray films on the same plane as the hips. According to this, select and prepare suitable artificial femoral heads and spare ones for each of the larger and smaller ones. 6. Special equipment for medullary cavity, artificial femoral head hammer, femoral head extractor, femoral head grasper, bone cement, etc. Surgical procedure 1. Position: side prone position, the affected limb is on, suffering from hip flexion 45 °, easy to move in all directions during the operation. According to the needs of the disease, when the anterior lateral exposure route is required, the patient is supine and has a high hip pad. 2. Incision and exposure: Any route can be fully exposed, depending on the patient's condition and the surgeon's habits. If there is hip flexion contracture, the anterior incision should be used. The posterior surgical approach is simpler [see the hip exposure route), the damage is small, and it is often used clinically. 3. Cut the switch capsule: After the joint capsule is exposed, the joint capsule "t" type or "i" type is cut open, and the joints of the femoral neck base joint capsule are opened, and the femoral head can be fully revealed. Neck and base. 4. Exploring and resecting the femoral head: Rotate the affected limb and probe the fracture of the femoral head and neck. It can be seen that the femoral head rotates in the acetabulum and continues to flex the internal rotation of the affected limb, so that the distal end of the femoral neck is unscrewed and revealed to remain in the acetabulum. The folded end of the femoral head. Use the femoral head extractor to drill into the head, pull away from the acetabulum, and use a pair of scissors to reach the head to cut the round ligament, then the femoral head can be removed. The diameter of the femoral head was measured and combined with preoperative filming to select an artificial femoral head of appropriate size. If the femoral head is necrotic, the hip joint is adducted, internally rotated, and flexed 90°. After the hip joint is dislocated, the femoral head is removed by a wire saw on the predetermined osteotomy line. Remove all soft tissue from the acetabulum and fill it with gauze. Flexion, adduction, and internal rotation of the affected limb expose the femoral head and neck and the medullary cavity to the surgical field. 5. Correction of the femoral neck: Excision of the excess femoral neck, the tangential end from the upper edge of the base of the femoral neck. Tangentially inward and downward, stopping at 1.0 to 1.5 cm on the small trochanter, retaining the femoral distance, and inclining the bone to the front by 15° to 20° to maintain the anteversion angle after implantation of the artificial femoral head. After the bone is cut, the soft tissue around the femoral neck is covered with a wet gauze, and a rectangular hole is scraped on the longitudinal axis of the cut surface, which is equivalent to the base of the handle of the artificial femoral head. The special medullary cavity is used to enlarge the medullary cavity to the size of the prosthesis handle. Note that in the process of expanding the medullary cavity, it is necessary to grasp the direction and avoid passing through the side wall of the femoral shaft. Finally, insert the femoral head handle to remove excess bone to ensure the physical placement and bone support of the prosthesis. 6. Place the artificial femoral head: Place the selected femoral head directly in the acetabulum and test if it is suitable. It should be the same size as the head lice, free to move, and have a certain negative pressure when the acetabulum is pulled out. The domestic ii type artificial femoral head has two holes on the handle for bone grafting or bone cement for fixation. Therefore, the prosthesis stem inserted into the medullary cavity can be fixed by stuffing bone graft or bone cement (bone cement). Before fixation, the artificial femoral head handle should be inserted into the medullary cavity and returned to the acetabulum to check whether the prosthesis placement position and the range of artificial joint movement are appropriate. If there is any improper treatment, it should be remedied and finally fixed. (1) Bone fixation: the femoral head holder was used to fix the lateral hole of the artificial femoral head, and the anteversion angle of 15° was maintained. The long axis of the artificial femoral head and neck was placed along the long axis of the femoral neck and the artificial femoral head was inserted into the medullary cavity. The part is hammered in slowly using a hammer. During the hammering process, the cancellous bone is embedded in the hole of the prosthesis stem, so that the bone graft and the bone are healed and fixed. Finally, the hammer to the femur is just about the inside of the bottom surface of the artificial femoral head. However, this method is not fixed firmly, and the zona pellucida and the hardening zone are prone to occur around the artificial femoral head stalk, which is the result of loosening and is one of the main causes of postoperative pain. (2) Bone cement (bone cement) fixation: the cancellous bone inside the medullary cavity is scraped off, leaving only the cortical bone, so that the bone cement can be firmly adhered. Rinse the medullary cavity, remove all bone debris, blood and clots, then use dry gauze to stop bleeding. Be sure to fill the bone cement in a dry environment. In order not to mix the bone, blood and water on the gloves, the surgeon should replace the dry and clean gloves. Then, the bone cement is prepared, and the bone cement with a sticky phase is filled with a finger or a cement gun in the trunk cavity of the femur, and the lower end is beyond the lower end of the bone stem. It is best to place a bundle of cement plugs at the distal end of the shank so as to prevent the bone cement from entering the medullary cavity too much. Finally, the artificial femoral head is hammered according to the above method while maintaining the anterior angle of the artificial femoral head and neck. . In order to reduce the absorption poisoning of the bone cement monomer, before filling the bone cement, the femoral shaft corresponding to the lower end of the artificial femoral head stem should be drilled and passed through the medullary cavity, thereby inserting a plastic catheter with a diameter of 3 mm, filled with heparin. The liquid causes the monomer released from the gas in the medullary cavity and the bone cement to be discharged from the catheter during the polymerization process. After the prosthesis is placed, the position of the artificial femoral head should be maintained. After the bone cement is polymerized and dried (about 10 to 20 minutes), the retention force can be relaxed and the catheter can be pulled out. A plastic tube can also be placed from top to bottom to remove blood and gas during filling of the bone cement, and gradually pull out with the cement filling. Remove excess bone cement from the spilled bone. 7. Reset the artificial femoral head: Pull the limb and push the artificial femoral head with your fingers. When it is close to the acetabulum, the lower extremity is externally rotated to make the head into the acetabulum. A chute plate can also be inserted into the ankle to allow the artificial femoral head to slide along the slope into the acetabulum. Note that the strength of the externally rotated femur should not be too large to prevent fractures in patients with osteoporosis due to rotational violence. After the reduction, the abduction and adduction hip joint test can be performed, and the degree of activity and the tendency to dislocate should be noted. 8. Place the negative pressure drainage, suture the wound: completely stop the bleeding, soak the wound with 1 Xin Jieer liquid for 5 minutes, then rinse with normal saline, and then suture the joint capsule with silk. A vacuum suction tube is placed near the artificial femoral head, and a small incision is made on the nearest skin to lead the tube out of the skin. The wound is layered and sutured. The drainage tube is fixed, and the nozzle is wrapped with sterile gauze, and the back pressure ward is connected to the negative pressure suction device.

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