P5. Experimental study on the expression of growth factors in the vertebral growth plate and pedicle in severe idiopathic scoliosis

Abstract

BACKGROUND CONTEXT Some scoliosis can progress to severe scoliosis with significant wedge deformities in the apex vertebra. Vertebral growth plate is closely related to the longitudinal growth of vertebral body, and the role of the growth factors expression in growth plate in the occurrence and development of severe spinal deformities has not been studied so far. PURPOSE To investigated the expression of multiple growth factors in the concave and convex vertebral growth plate and pedicle in severe idiopathic scoliosis. STUDY DESIGN/SETTING A PATIENT SAMPLE Severe scoliosis and no significant cardiopulmonary dysfunction, no significant malnutrition, and no abnormal bone metabolism were included in this study. Congenital, neuromuscular, neurofibromatosis, connective tissue disease and syndrome scoliosis were excluded. OUTCOME MEASURES The specimens were observed histologically. Immunohistochemistry was used to observe the differences of TGF, FGF, BMP and IGF expression. METHODS Severe scoliosis and no significant cardiopulmonary dysfunction, no significant malnutrition, and no abnormal bone metabolism were included in this study. Congenital, neuromuscular, neurofibromatosis, connective tissue disease and syndrome scoliosis were excluded. Growth plate and pedicle specimens of convex and concave side of the vertebra in the apical region were obtained during the PVCR. The specimens were observed histologically. Immunohistochemistry was used to observe the differences of TGF, FGF, BMP and IGF expression in the pedicle and growth plate of concave and convex side of the apex vertebra. Semi-quantitative analysis was carried out by immunohistochemical image analysis system. Statistical analysis was carried out on the results, with P RESULTS Ten patients (6 male, 4 female) were included in this study, with an average age of 17.6 years, and the apex vertebra was located between T6 to T12. The preoperative mean coronal deformity was 127.7° (96°-158°), and the sagittal deformity was 115° (85°-150°).The cells in the cartilage layer of the apex vertebral were disordered, the cartilage matrix was not uniform, and the concave side was thin. The fibrosis was aggravated in the matrix and accompanied by focal calcification. Some chondrocyte aggregation was observed. Bone density increased in the concave side of the pedicle. Immunohistochemical staining results showed that FGF, BMP and TGF had basically similar expression characteristics, and the expressions in the convex side of growth plate and pedicle of the apex were higher than the concave side, which had statistical significance(p CONCLUSIONS The expressions of growth factors in the growth plate and pedicle of the apex were different in patients with severe idiopathic scoliosis, and the imbalance of growth factor expression is one of the factors that cause significant deformity in such patients. Abnormal expression may lead to the significant development of the deformity, and the abnormal mechanical environment caused by the significant deformity in the later stage may jointly lead to the further development of the deformity. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.