Factors correlated with height gain after posterior spinal correction surgery in lenke 1 adolescent idiopathic scoliosis

Objective To investigate the correlated factors of height gain (ΔSH) after posterior spinal correction surgery in Lenke 1 adolescent idiopathic scoliosis (AIS), and to propose the predictive model of ΔSH. Methods From 2013 to 2015, a total of 150 Lenke 1 AIS patients undergoing posterior spinal correction surgery were included in the study, with the age of (14.3±2.9) years. The Cobb angle of major curve, thoracic kyphosis (TK) and lumbar lordosis (LL) were measured on both pre-op and post-op standing whole spine x-rays. The change in Cobb angle, TK and LL were calculated. The difference between pre-operation and post-operation was compared and the linear regression analysis was used for the predictive model of ΔSH. Results The pre-op and post-op values were (41.6±3.0)cm and (43.9±2.7)cm for spinal height (SH)[ΔSH=(2.4±0.8)cm, P=0.000]; (50.5±10.4)° and (14.6±6.4)° for Cobb angle (P=0.000). The Pearson correlation analysis showed that ΔSH was significantly correlated with pre-op SH (P=0.000), pre-op Cobb angle (P=0.000), pre-op TK (P=0.000), post-op SH (P=0.020), post-op Cobb angle (P=0.000), change in Cobb angle (P=0.000) and change in TK (P=0.000). The linear regression model 1 revealed that ΔSH was linearly correlated with change in Cobb angle (P=0.000) as well as change in TK (P=0.000); the linear regression model 2 showed that the pre-op Cobb angle (P=0.000) and pre-op TK (P=0.020) could be used for the pre-op prediction of ΔSH. Conclusions The positively correlated factors of ΔSH include pre-op and post-op Cobb angle, TK, change in Cobb angle and change in TK. High pre-op Cobb angle and TK indicates high height gain in Lenke 1 AIS patients. Key words: Scoliosis; Adolescence; Body height; Factors analysis statistical; Posterior spinal correction surgery