Theoretical summary
Congenital scoliosisThe incidence rate is about 1%.
So far, the cause of vertebral deformity is unknown. Animal experiments in rats have shown that exposure of the embryo to carbon monoxide can induce spinal deformities. Clinical studies have shown that pregnant women with diabetes, or taking anti-epileptic drugs during pregnancy, may also cause spinal deformity in the fetus. Gene abnormalities play a role in the occurrence of congenital scoliosis, but the genetic law is not clear.
The development of modern imaging techniques has enabled fetuses with congenital spinal deformities to be diagnosed during the fetal period, but there is no way to treat them.
With the advancement of 3D CT imaging technology and MRI technology, the diagnostic level of congenital scoliosis has been greatly improved, such as the size, position, segmentation of the hemivertebra, malformation in the spinal canal, and development of the spinal cord. Previously understood more accurately, which provides a reliable basis for accurate assessment of patients, the development of more reasonable surgical procedures, and safer surgery.
Children with congenital spinal deformity have rib deformities, especially rib fusion. These patients have short thoracic, thoracic deformities, and decreased lung function, which can lead to severe restrictive lung dysfunction and chest insufficiency. In recent years, this problem has gradually gained attention and solutions have been obtained. Titanium rib prosthesis implantation and thoracic cavity expansion have also begun to be carried out in China.
Classification of congenital scoliosis: classification of deformed vertebral bodies that cause congenital scoliosis, poor vertebral formation, such as hemivertebra and wedge-shaped vertebrae; poor vertebral segmentation, such as the bone bridge on the concave side of the scoliosis Vertebral fusion malformation; and a mixed type with both poor vertebral formation and poor segmentation. In fact, the hybrid type is more common and the processing is more difficult. Scoliosis caused by multiple vertebral malformations often combined with rib deformities.
Natural history of congenital scoliosis: Unbalanced growth on both sides of the spine will cause the progression of the lateral curvature. If the growth plate of the deformed vertebral body shows good development on the X-ray film, the growth of the spine will be unbalanced, causing the curvature of the side curve to increase. That is, the fully segmented semi-vertebral body has the greatest risk of causing side-bend weighting. If the growth plate of the malformed vertebral body is poorly developed, ie, it is fused to the adjacent vertebral body above or/and below it, the lateral curvature does not progress very quickly. Similarly, asymmetric axillary structures on both sides of the spine, the concave side of the bone bridge and the fusion ribs, can also cause rapid progression of the lateral curvature.
The rate at which the congenital scoliosis progresses depends on the type of deformity vertebral body, the age of the child, and the location of the curvature of the curve. Five years after birth and adolescence are two periods in which the curvature of the lateral curvature progresses relatively rapidly. These two periods are the rapid stages of spine growth and development. At the junction of the cervical vertebrae and the thoracic vertebrae, the deformity of the junction between the lumbar vertebrae and the atlas is more likely to cause the development of the lateral curvature than other parts. The most likely case of aggravation of the lateral curvature is the presence of a bone bridge on the concave side and the presence of a semi-vertebral body on the opposite side. Followed by a unilateral bone bridge, unilateral hemivertebra or wedge-shaped vertebrae, the most stable condition is a large segmental vertebral deformity with poor segmentation. The progress of complex mixed spinal deformities is the most difficult to predict, and the degree of progression of the lateral curvature depends on the asymmetry growth factors in the deformity.
Patients with congenital scoliosis should be evaluated in three ways: physical examination, combined malformations, and imaging studies. Physical examination should weigh the child's weight and height, because growth and development play an important role in predicting whether the curvature of the lateral curvature is aggravated. Care should be taken to check for skin pigmentation on the surface of the spine, hair growth, and other neoplasms. If these skin problems are present, there is often a suggestion of an intraspinal deformity. Children with intraspinal malformation also have manifestations in the lower extremities, such as bilateral gastrocnemius asymmetry, high arched foot, clubfoot, vertical talus and abnormal nerve reflex. The spine itself should be concerned with the presence of trunk or pelvic imbalance. Whether the rib has a razor back deformity, and whether the chest wall has abnormal activity with the breathing, it is necessary to pay attention to whether there is a manifestation of chest insufficiency. The balance of the lateral side of the spine should be evaluated from the coronal and sagittal positions, whether the torso is tilted, whether there is a torticollis deformity, whether the shoulder is balanced, and whether the pelvis is balanced. Children with spinal canal malformations are also required to undergo a comprehensive neurological examination such as muscle tone, sensation, and nerve reflex.
About 35% of children with congenital scoliosis have intraspinal malformations, such as spinal cord fissure, spinal cord hernia, Chiari malformation, and intradural lipoma. Children with intraspinal malformations often have abnormalities on the surface of the skin, but there are cases of intraspinal malformations in cases without skin abnormalities.
25% of children with congenital scoliosis had congenital heart disease. The type of congenital heart disease ranges from simple atrial dysplasia to ventricular dysplasia to complex Faro's quadruple disease and aortic dislocation. Children with congenital scoliosis should be routinely examined for echocardiography before surgery.
20% of children with congenital scoliosis have genitourinary malformations. Malformations can involve the kidneys, ureters, bladder and urethra. Common malformations include horseshoe kidney, kidney dysplasia, double ureter, and hypospadias. Children with congenital scoliosis should be routinely performed urinary B-ultrasound before surgery.
Congenital spinal deformities often also involve skeletal muscle system malformations, such as congenital clubfoot, congenital high shoulder spasm, short neck deformity, hip dysplasia, and limb deformities.
X-ray plain film plays an important role in the initial diagnosis and follow-up of congenital scoliosis. More accurate spinal deformity examinations rely on three-dimensional CT imaging. Three-dimensional CT imaging has been routinely examined as a preoperative routine examination for children with congenital scoliosis. It has 100% accuracy in understanding spinal deformities and can detect anatomical changes that are not visible on X-ray films. In addition to the spine, three-dimensional CT imaging should also include the thoracic portion. Three-dimensional imaging of the thorax can observe rib deformities and chest wall deformities. The thoracic deformity is important for the diagnosis of thoracic insufficiency syndrome and for evaluating the improvement of postoperative pulmonary function.
MRI has replaced myelography and has become an effective means of examining intraspinal malformations. However, MRI is not used as a routine examination before congenital scoliosis. In general, for progressive congenital scoliosis, severe congenital scoliosis, and cases of abnormal neurotransmission, cases of neural tube defects require MRI. In addition, MRI can also be used to evaluate postoperative spinal canal decompression in children with congenital posterior kyphosis.
In addition, in order to understand the flexibility of the spine, some special X-ray examinations are needed. For example: the lateral position of the spine under traction, the positive lateral position of the spine under the push of the prone position, the right and left lateral flexion of the supine position, and the positive image of the spine after the padding. These special photographic techniques facilitate the development of a reasonable spinal fusion segment.
Surgical principles: Congenital scoliosis is characterized by early and timely intervention before the scoliosis becomes severe. However, the risk of neurological dysfunction in congenital spinal deformity surgery is higher than in idiopathic scoliosis. There are several ways to reduce perioperative neurological dysfunction: first, preoperative MRI to assess the condition of the spinal cord. In general, spinal deformities should be performed before spinal surgery or at the same time. Secondly, the correction is performed before the side bend becomes severe, and the safety of the operation is high. Third, the scoliosis surgery, try to use the spine shortening procedure, reduce the spine lengthening surgery, because the spinal cord will be pulled during spinal extension surgery. Fourth, control hypotension should be used cautiously during surgery to avoid spinal cord ischemia, especially during spine rotation, distraction or compression orthopedic procedures. Fifth, intraoperative exercise and sensory evoked potential monitoring should be routine. In general, a wake-up test is required if the baseline is not determined during surgery, the likelihood of neurological dysfunction during the perioperative period is increased, or the intraoperative monitoring waveform cannot be returned to baseline. In order to ensure the safety of the operation, it is necessary to routinely perform a wake-up test after surgery. However, the wake-up test is difficult for children who cannot cooperate. Postoperative monitoring of spinal cord function is equally important because clinically delayed cases of paraplegia occur primarily at 72 hours postoperatively.
With the advent of new low-cut titanium metal spine-incorporated instruments, the use of built-in instruments has been commonly used in the correction of children with congenital scoliosis. Advances in pedicle screw technology have made pedicle screws have been applied to children 1 to 2 years of age without increasing the risk of surgery. In addition, studies have shown that the use of the spinal fusion effect, orthopedic effect and maintenance of orthopedic effects are superior in the two groups of patients with and without spinal implants.
Surgical methods:
In situ fusion is a safe surgical procedure. In situ fusion is a good choice for children with vertebral deformity but with increased curvature of curvature. Prophylactic in situ fusion of fully segmented vertebral bodies is highly desirable. In situ fusion has no loss of spine length and good long-term results. Successful in situ fusion requires complete removal of the articular process, laminectomy and cortical bone, and a large number of bone grafts. In cases of scoliosis, whether in situ fusion requires anterior discectomy depends on the growth potential of the anterior disc, the future growth capacity of the spine, and the size and location of the curvature of the side. These can be judged by X-ray film, CT and MRI. Sometimes, even if the intervertebral disc is very narrow, there is a case of crankshaft phenomenon after in situ fusion in the posterior approach. For cases of spine protrusion, only the fusion of the anterior spine is enough to control the development of the deformity. In the case of kyphosis, only the in situ fusion of the posterior vertebral column is performed. By inhibiting the growth behind the spine and maintaining the growth of the anterior approach, the progression of kyphosis can be effectively controlled. The surgical approach to in situ fusion of the anterior spine can be achieved through an open approach, a thoracoscopic approach, and a pedicle approach.
The convex side half fusion of the spine is a method of partial growth inhibition. It is suitable for cases with low growth potential on the concave side, that is, cases suitable for hemivertebra, but not for cases with poor segmentation. In general, this procedure is suitable for cases under 5 years of age with moderate deformity. Follow-up showed that the final correction of the procedure was less than 15° or no correction. For cases with small deformities, the convex side of the spine can also be combined with hemivertebra resection and wedge resection. For cases with large deformities, it can be combined with concave growth rod technology and VEPTR technology.
Semi-vertebral resection for the isolated hemivertebra, which causes lateral curvature progression and trunk imbalance. In situ fusion and lateral convex fusion of the spine have a good effect on inhibiting growth and controlling the development of scoliosis, but neither can correct lateral curvature and trunk tilt. The ideal indication for hemivertebra resection is: age less than 5 years, the semi-vertebral body is located in the thoracolumbar spine, lumbar vertebrae or lumbosacral vertebrae, and combined with trunk imbalance.
The advantage of the anterior-posterior approach to resection of the hemivertebra is that the semi-vertebral body is clearly visible and can remove the vertebral body and its upper and lower intervertebral discs, requiring only one anesthesia. However, the operation time is longer, the child has a greater surgical impact, and the position is changed and the sterile towel is re-sewed during the operation.
Simple posterior hemivertebra resection is most suitable for thoracolumbar spine, lumbar vertebrae, and kyphosis.
For those congenital scoliosis with better vertebral segmentation and spinal flexibility and less severe trunk deformity, standard posterior instrument placement and spinal fusion can be performed. Whether to increase anterior surgery, there are two situations to consider. 1 The imaging examination of the child showed that the intervertebral disc space was basically normal and had great growth potential. This type of patient will have a crankshaft phenomenon in simple posterior surgery. 2 moderate spinal deformity, intervertebral disc space is basically normal, but the spine is less flexible. Performing anterior surgery in such children is beneficial for correcting spinal imbalance.
Corrective surgery for severe congenital scoliosis is a serious challenge and faces greater risks. Spinal osteotomy, circumferential or osteotomy or rib vertebral resection is often required.
The method of severe stiff scoliosis combined with traction therapy will improve the safety and correction rate of the operation. Commonly used methods are Halo ring gravity vertical traction method, occipital jaw with femur horizontal traction method. Traction can be performed before and after the anterior spine is released.
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