| Objective:Congenital scoliosis is a kind of three dimensional deformity. The purpose of this study is to explore the clinical value of multi-slice helical computed tomography (MSCT) in orthopedic surgery via comparing it with x-ray in visualizing of the deformity.Materials and Methods:37 adolescents of congenital spinal deformity were studied from 2003 to 2006.A11 the patients were examined by both plain radiography and MSCT. 37 cases were classified into 3 grades according to the utility of the advanced MSCT reformatted images(MPR, CPR and VR images) as the following: Grade A (substantial new information obtained), Grade B (confirmatory with improved visualization and understanding of the deformity), and Grade C (no added useful information obtained). 19 cases were studied by MPR of MSCT before orthopedic operation, the parameter about vertebral arch was measured precisely to sure if it is suitable for the implantation of the screw, to arrange the diameter, length and angle of the implanting screw, to plan the detail of the operation. 9 cases were studied after orthopedic operation, the locations of implanting screws was evaluated, to know whether the screws penetrated the anterior compact bone of vertebral body or not, to observe the relationships of screws and vertebral canal. 20 cases suspected nervous system abnormalities were examined by MRI of spinal cord before operation. Results :In 37 patients, Grade A: 25cases (229 deformities, 78. 16%), Grade B: 5cases (29 deformities, 9.90%), Grade C: 7cases (35 deformities, 11.95%). 64 deformities were found by x-ray in all. 293 deformities were detected by MSCT. All of the deformities found by x-ray and additional 229 deformities (25 cases) were detected by the advanced reformatted images of MSCT. In all cases, there were 6 cases congenital scoliosis with urinary anomaly found by MSCT, include ectopic kidney in 2 cases, horseshoe kidney in 1case, hydronephrosis in 3 cases.About the location of deformities, 2 cases located in cervical vertebrae, 12 cases in thoracic vertebrae , 8 cases in lumbar vertebrae , 4 cases in cervical-thoracic vertebrae, 7 cases in thoracic-lumbar vertebrae , 2 cases in lumbar-sacral vertebrae , 2cases in cervical-thoracic-lumbar. 20 cases suspected nervous system abnormalities were examined by MRI, TCS in 5 cases, diastematomyelia in 5 cases, syringomyelia in 3 cases, Chiari-I malformation in 1 case, meningomyelocele in 2 cases, 4 cases were normal.The parameter about 208 vertebral arches of 19 cases (28 hemivertebraes) was measured precisely by MPR before orthopedic operation. Breadth of 161 (77.40%) vertebral arches equal or exceed than 3.5mm, 35(16.83%) less than 3.5mm, 7 (3.37%) vertebral arches had none of development, and 5 (2.40%) vertebral arches were abnormal. (Note: In the cases, the least diameter is 3.5mm, length from 10mm to 50mm of implanting screw)The locations of implanting screws of 9 cases were evaluated after operation. In 6 cases, the positions of screws were satisfactory. A screw penetrated the anterior compact bone of vertebral body in a case, but the great vessel weren't injuried by it. In another case, a screw was adjacent to the spinal canal because the screw breaked corresponding vertebral arch, but the patient had not symptom. The third patient had dyskinesia and sensory disability because a bone graft crushed the spinal cord, then the symptom disappeared after second operation. Conclusion :3D CT combined with CPR and MPR images can clearly display the whole and detailed anatomy structure of congenital spinal deformity and obtain more useful information not appreciated on plain radiographs. CPR images can describe the whole scoliotic spine in coronal and sagittal plane and have more advantage in observing congenital spinal deformity wholly, and it can provide actual evidence for operating plan. The parameter of vertebral arch can be measured precisely by MPR before orthopedic operation. It is benefit to choice implanting screw and helpful to plan the pathway of screw into the vertebral arch. The advanced MSCT reformatted images can offer objective witness for examination of patient after orthopedic operation. |
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