Dwyer Anterior Spinal Orthopaedic Surgery

Dwyer anterior spinal orthopedic surgery is used for the surgical treatment of idiopathic scoliosis. Scoliosis is one of the most common spinal deformities. It means that one or several segments of the spine are bent laterally off the midline in the coronal plane, forming a curvature of the spine with a curvature of 10°. Diagnostic criteria, usually accompanied by an increase or decrease in the rotation of the spine and physiological lordosis and kyphosis in the sagittal plane. Lonstein et al. in the United States, Minnesota census, children aged 12 to 14 years old, 1.47 million people, found that there are scoliosis accounted for 1.1%, China Peking Union Medical College Hospital in Beijing 8 to 14 years old school age children, the incidence of scoliosis was 1.06%, Guangzhou Sun Yixian Memorial Hospital conducted a general survey of 7-19 year old students in some urban and rural areas in Guangdong, and found that the incidence of scoliosis was 0.75%. Scoliosis is a clinical diagnosis rather than an etiological diagnosis that can be caused by many diseases and can be divided into two broad categories depending on its cause. The first category is scoliosis, which is also known as idiopathic scoliosis. The initial onset age is mostly 10 to 13 years old. The diagnosis depends on medical history, symptoms, signs and necessary imaging studies. Current studies suggest that idiopathic scoliosis may be related to the following factors: 1 genetic factors; 2 hormone effects; 3 growth and development asymmetry; 4 connective tissue dysplasia; 5 neuro-equilibrium system dysfunction; 6 neuroendocrine system abnormalities; Others, such as older mother offspring and abnormal copper metabolism. The second category is scoliosis with known causes, including congenital scoliosis and neuromuscular scoliosis. Congenital scoliosis is a lateral curvature of the spine resulting from an imbalance in the longitudinal growth of the spine caused by vertebral malformations. The critical period of embryonic spine development is the fifth to sixth week of pregnancy, which is the time of the spine segmentation. Spinal deformity occurs in the first 6 weeks of pregnancy. The diagnosis of congenital scoliosis can only be made if an abnormality is observed on the radiograph of the spine. Neuromuscular scoliosis is a group of conditions characterized by loss of normal function in the brain, spinal cord, peripheral nerves, neuromuscular junctions, or muscles. It is generally believed that the loss of muscle strength or control of voluntary muscles, or loss of sensory function such as proprioception in young children with soft spine and rapid development is a factor in such lateral curvature. Most neuromuscular scoliosis is a longer "C" shape, involving the humerus, and common pelvic tilt, even small neuromuscular scoliosis continues to develop after skeletal maturity, many neuromuscular scoliosis Bending deformities require surgery. For idiopathic scoliosis, the degree of rotation of the vertebral body can be determined and measured by lateral displacement of the position of the spinous process or by displacement of the pedicle. According to the spinal range of the thoracic scoliosis and the functional structural state of the distal compensatory curve, King divided the thoracic scoliosis with structural scoliosis into the following types: 1King type I, the chest bend and the waist bend both exceeded the midline. "S" shape, the flexibility of the chest bend is greater than the waist bend; 2King II type, the chest bend and the waist bend are beyond the midline, showing an "S" shape, the Cobb angle and rotation of the chest bend are larger than the waist bend, and the waist bend is soft. More than the chest bend, the stable vertebra is often T12 or T11 or L1; 3King III type, the waist bend accompanied by the chest bend does not exceed the midline, and the waist bend is non-structural, generally no rotation in the standing position; 4King IV type, is a Long chest bend involving more spine, the vertebral vertebra usually enters the long thoracic curve at T10, L4, the appearance is abnormal, but L5 is still located in the center of the humerus; 5King V type, the upper and lower chest bends are structural, T1 upward chest The concave side of the bend is inclined, and T6 is often the boundary vertebra of the two bends. This classification system is mainly used to guide the selection of the level of fusion during orthopedic surgery. The pathological changes of scoliosis mainly show the lateral curvature of the spine. The first part of the curvature is called the primary side bend, and the opposite direction of the upper and lower bends is the compensatory side bend. In the intervertebral space within each bend, the concave side is significantly narrowed, and the convex side is widened, wherein the most convex portion, that is, the widest point of the convex side intervertebral space is the apex of the curvature. As the lesion progresses, spine rotation deformities are usually combined, and the development of the vertebral body, lamina, and pedicle is affected on the concave side. The soft tissue on both sides of the spine will also change, showing that the soft tissue on the concave side is contracted and thickened, while the convex side is elongated, thereby aggravating the vertebral deformity. Because the thoracic vertebra is a part of the thoracic spine, the thoracic and thoracolumbar scoliosis, the thoracic and ribs are also deformed accordingly, and the convex rib angle is increased to make the posterior chest wall a "razor back" deformity, and the concave side rib is horizontal. The side chest wall protrudes forward. Due to the above changes, the chest volume becomes smaller, and the internal organs are suppressed or displaced, so the cardiopulmonary function is affected to some extent, and the severe condition even causes the spinal cord to be compressed, causing spinal cord injury. An abnormality of the thoracic kyphosis of the spine over 50° is abnormal. If the anterior column of the spine is unable to withstand the pressure, causing the anterior column to contract, a kyphosis will occur. The posterior column of the spine is broken, and the inability to resist tension can also cause the posterior column to be relatively elongated. Abnormal kyphosis can be corrected by shortening the posterior column or extending the anterior column, or shortening the posterior column and extending the anterior column. Congenital kyphosis can be divided into three types. That is, congenital vertebral body formation disorder (type I), congenital vertebral body segmentation disorder (type II) and mixed (type III). Treating diseases: scoliosis Indication Dwyer Anterior Spinal Orthopaedic Surgery is available for: 1. Idiopathic thoracolumbar scoliosis with anterior convexity. 2. The vertebral body attachment of thoracic scoliosis is poorly developed, the lamina is too thin, the articular process is too small, and it is not suitable for Harrington's rod correction or lumbar scoliosis with dural bulging. 3. Stiff thoracolumbar paralysis, requiring two-stage anterior and posterior fusion. 4. Those aged 12 to 18 years old. Contraindications 1. For those with scoliosis involving T8 or above, because the thoracic vertebral body above T8 is small, screwing into the vertebral body screw can easily penetrate the vertebral body into the spinal canal and cause spinal cord injury. 2. Scoliosis with obvious pelvic tilt. 3. Scoliosis with obvious kyphosis. This procedure can make the kyphosis worse. 4. The patient's lung capacity and maximum respiration have been reduced by 40%. Due to the use of analgesics and post-thoracic and spinal orthopedics, lung volume and vital capacity will be reduced by 10% to 30%, which may cause acute lung failure. 5. Those aged <10 years old. Because the vertebral body is too small, it is not appropriate to wear nails on the vertebral body. This method should not be used by patients with osteoporosis. Preoperative preparation 1. Take the full-length positive X-ray of the spine and the full-spine full-shoulder slice to measure the degree of lateral curvature and vertebral rotation according to the X-ray film, and compare the suture position to measure the natural correction rate to understand the operation. Correct the maximum limit. For congenital malformations, especially those with suspected spinal cord longitudinal fissure should be performed first, and those with conditions can do CT scan or MRI. If it is confirmed that this disease is the first intraspinal bone septal resection. 2. Electrophysiological examination can be performed on the paraspinal muscle and lower extremity electromyography or spinal cord evoked potential examination. In order to understand whether there is spinal nerve damage, and as a control for intraoperative spinal cord monitoring. 3. Pulmonary function test to understand the extent of lung function, such as lung capacity below 60%, due to spinal surgery often reduce the original lung function by 15% to 20%, will lead to significant hypoxia. Therefore, lung function training must be performed before surgery, and the patient should perform deep exhalation training in the balloon. 4 to 5 times a day for 10 minutes each time, continuous 2 weeks will significantly improve lung capacity. 4. Blood biochemical examination blood CPK normal value is 2 ~ 130U / L, such as increased significantly, especially in the anesthesia above 1000U / L is prone to malignant hyperthermia, check blood potassium, sodium, chlorine and liver and kidney function, blood gas analysis, etc. Can fully understand the basic situation of the whole body. 5. The most important step in the traction of the skull pelvic ring is the traction of the skull pelvic ring, which is towed in the traction frame during the day and in the semi-recumbent position on the slope bed at night. The time is as long as 9 to 12 weeks. By pulling, the soft tissue is relaxed, and the deformity is corrected to a considerable extent. 6. Bed and toilet training After admission, the patient is trained to bed and urinate in bed, which can prevent urinary retention and constipation due to unaccustomed postoperative operation, and at the same time enable the patient to learn the correct axial turning method after surgery. 7. Application of antibiotics 24 hours before surgery, intramuscular injection or intravenous administration of a sufficient amount of broad-spectrum antibiotics can maintain the effective antibiotic concentration in the blood during surgery, and play a positive role in preventing postoperative infection. 8. Skin preparation Because the patient's back is uneven, it is necessary to master the skin preparation method. Do not shave the skin. For those with folliculitis, 2.5% iodine is applied locally. In severe cases, it can be treated with reasonable treatment. All the folliculitis can be treated before it can be treated. 9. After preoperative localization of the disinfected skin, the injection needle was inserted into the side of the spinous process in the center of the predetermined incision, and the vertebral body was confirmed by X-ray film, and then 0.5 ml of 1% methylene blue solution was injected. When the surgery is to be performed on the next day, the extent of the lamina can be accurately revealed. If the methylene blue solution has been absorbed during surgery (no injection of methylene blue solution into the periosteal tissue), it is best to further locate the intraoperative film. 10. Prepare blood for 800 to 1000ml. Surgical procedure Anesthesia was performed using an endotracheal tube. Take the lateral position and the convex side on the top. The folding surgical bed is folded into a "" shape to accommodate the side curvature. In addition, the torso plane is adjusted according to the needs of the operation. Incision A combined chest and abdomen incision was made with the spine. An oblique incision is made on the surface of the rib to be resected and extends to the outer edge of the rectus abdominis. 2. Reveal the vertebral body The 10th rib was removed according to the conventional method, and it was retained as the bone graft material. The periosteum and the parietal pleura of the rib were longitudinally cut, and then the retractor was placed to retract the incision, and then the collapsed lung was retracted. The horns push the aorta, inferior vena cava, kidney, and abdominal organs from the extraperitoneum to the opposite side. At this time, the vertebral body in the main convex range can be fully revealed, and the intercostal blood vessels and the traversing motion and the veins are firmly ligated. 3. Removal of the intervertebral disc According to the patient's preoperative standing position X-ray film to determine the extent of the fixed vertebral body, the vertebral body is made subperiosteal peeling, and then the intervertebral disc is wedge-shaped, the wedge-shaped base is on the convex side, but the concave side fiber ring is retained. The periosteum at the edge of the vertebral body was peeled off by 0.5 cm to prevent soft tissue from being embedded between the vertebral bodies. 4. Place the internal fixation device and spinal orthosis Insert a special "U" nail into the upper and lower edges of each vertebral body from the convex side, and then insert a special metal wire with a small hole through the U-shaped nail hole. A small hole in each screw cap. After wearing, use a special tightener to tighten, so that each vertebral body after the removal of the intervertebral disc abuts each other until the scoliosis is satisfactory. Then use a crimper to tighten the screws. If there is a small gap between the vertebral bodies, cut the ribs into small pieces and insert them into the bone graft. 5. Close the incision After completely stopping the bleeding, the saline rinses the wound. Place the chest vacuum to attract the drainage tube. The thoracic and lumbar vertebrae were covered with the pleura and the psoas muscles, respectively. The incision was sutured layer by layer. complication 1. Postoperative spinal deformity can be aggravated. 2. Spinal cord injury: Causes of injury: 1 spinal cord ischemia caused by improper ligation of the lumbar transverse vessels; 2 accidental injury of the spinal cord when the disc is removed; 3 mistakenly inserted into the spinal canal when the vertebral body screw is placed. 3. : When the incision is closed, the free part of the transverse angle is not fixed. 4. Vertebrate fragmentation: caused by improper position of the screw. 5. The steel wire at both ends of the metal rope is opened, and the sharp wire end can stab the important tissues and organs nearby. 6. Pseudo-articular formation: occurs mostly in stiff paralytic lateral deformities. Dwyer reports that the incidence of this complication is as high as 50%, so it is emphasized that stiff paralytic lateral curvature should be added with posterior spinal fusion. 7. Acute pulmonary failure: correction of surgical incision and scoliosis can involve chest volume and vital capacity, and prone to acute lung failure. Most scholars believe that the preoperative lung vitality and maximum respiration have been reduced by 40%, the risk of postoperative acute pulmonary failure is significantly increased, so preoperative lung function training is emphasized. 8. Others: There may be complications such as pneumothorax, hemothorax, aspiration pneumonia and intestinal paralysis.