Dwyer surgery

For most patients with spinal deformity, posterior surgery is appropriate, but for some patients, posterior surgery can not achieve orthopedic goals. In 1964, Dwyer designed a sinus surgery device to correct scoliosis. The advantages of this operation are: 1 removal of the intervertebral disc can increase the activity, so that the correction of each segment is satisfactory; 2 can correct the lordosis; 3 can correct the scoliosis with rotational deformity. Disadvantages are: 1 surgical access time; 2 patella device is difficult, so it is difficult to correct pelvic tilt; 3 chest 6 level above the device is difficult to insert; 4 false joint incidence is higher, because the insertion of two washers in each intervertebral space 5; prone to lumbar kyphosis, which is due to the connection of the screw is a soft steel cable. The related anatomy of the operation is shown in the figure below. Treating diseases: scoliosis Indication Dwyer surgery is suitable for thoracolumbar or lumbar scoliosis, especially in patients with myelomeningocele and severe lordosis who are unable to place Harrington rods. Contraindications 1. Patients with scoliosis and kyphosis. 2. Children under the age of 10, due to small vertebral body, thick cartilage, and low bone mass, are not easy to fuse. 3. Adults with severe osteoporosis cannot fix the screws securely. Surgical procedure Incision Taking the 10th rib as an example, the upper end of the incision is cut vertically from the side of the thoracic spine 5 cm, and then along the 10th rib to the anterior edge of the rib, to the abdomen posterior oblique rectus. The umbilical and pubic symphysis are combined with the midpoint. 2. Reveal Cut the skin and superficial fascia, then cut the latissimus dorsi, anterior serratus and other tissues. The 10th rib was removed and the resected ribs were retained in isotonic saline for bone grafting. The rib bed and the parietal pleura were cut, and the saline gauze pad protected the soft tissue on both sides of the incision. Open the incision with a chest opener and cut the three layers of abdominal muscles through the abdominal incision. Carefully remove the peritoneum from the diaphragm muscle, pay attention not to break the peritoneum, once broken, immediately suture, cut the diaphragm at a distance of 2.5cm from the stop point, cut the side to suture, in order to facilitate suturing, use isotonic The saline gauze wrapped the fingers, carefully peeling the peritoneum, kidney and ureter bluntly, and pushing it away from the midline to expose the psoas muscle, vertebral body and aorta. Carefully strip the aorta and retract it. The left temporal angle was cut on the anterior longitudinal ligament of the upper lumbar spine, and the stop of the arcuate ligament was separated on the lumbar 1 transverse process, and the incision of the diaphragm was extended by the arcuate ligament. 3. Removal of the intervertebral disc Increasing the curvature of the scoliosis by the operating bed rocker bridge facilitates the removal of the intervertebral disc. Excision and scraping of the disc tissue reached the cancellous bone, but the upper and lower edges of the upper and lower vertebral bodies were not removed, and only the traces were made for the insertion of the gasket blades. 4. Place Dwyer instruments According to the transverse diameter of the vertebral body, select the appropriate length of the screw and the washer, and punch the hole at the midpoint of the side of the vertebral body. The nail hole at the side of the lateral bend should be behind the vertebral body to facilitate the correction of rotation and prevention of lumbar kyphosis. Put the washer on the upper and lower vertebral bodies, and then screw the screws one by one. One finger is placed on the opposite side of the vertebral body, and the screw is screwed to the contralateral cortex. It is just right to touch the nail tip. Flatten the operating table, take a steel cable, fix the button to one end of the cable, pass through the screw head hole, wear the cable and intervertebral bone graft (with the removed rib), wear and bone graft Tightening at the side, finally pressurizing and inserting another button into the end of the cable. The screw sleeve hole is flattened by the instrument clamp, and the excess steel cable is cut off. Then suture the parietal pleura, place a chest drainage tube, and suture the diaphragm and chest and abdomen incision layer by layer. It should be emphasized that the Dwyer device does not provide a strong spinal fusion, and it is best to do posterior fixation after 3 weeks. complication 1. Common complications of combined chest and abdomen incision Common complications of chest and abdomen combined incision include pneumothorax, hemothorax, aspiration pneumonia, and paralytic ileus. 2. Spinal cord injury Often caused by mechanical damage to the screw. 3. Vascular injury Extensive dissection of the aortic branch vessels. 4. Cable damage and loose screws Often occurs in the later stages. 5. Pseudo joint formation The incidence rate is over 50%, and it is compensated by the use of posterior fusion.