Comparison of correction outcomes after anterior or posterior approach with lowest and vertebra instrumentation in adolescent idiopathic thoracolumbar/lumbar scoliosis

Abstract

To evaluate the different influences upon the correction outcomes after anterior or posterior correction and fusion with lowest end vertebra instrumentation in adolescent idiopathic thoracolumbar/lumbar scoliosis. By reviewing the medical records and roentgenograms of adolescent idiopathic thoracolumbar/lumbar scoliosis patients undergoing anterior (single rod-Group A) or posterior (all pedicle screws-Group B) correction and instrumentation, the parameters of Cobb angle of the curve, correction rate and disc angle were measured and analyzed. There were 18 patients in Group A and 21 patients in Group B. The curve included 5.0 vertebrae and 5.5 vertebrae (P = 0.134) respectively, and the fusion levels were 4.7 vertebrae and 5.4 vertebrae (P = 0.008) respectively. The mean pre-operative and post-operative coronal Cobb angles of the main curve in Groups A and B were 49.2 degrees and 10.3 degrees , 42.2 degrees and 5.0 degrees with an average correction rate of 78.5% and 87.8% respectively. The Cobb angles were all significantly corrected (all P = 0.000), and group B had a better correction result (P = 0.020). At final follow-up, the coronal Cobb angles in the two groups were 21.7 degrees and 7.7 degrees with an average correction loss of 8.3 degrees and 2.7 degrees (P = 0.001) respectively. The disc angles at pre-operation, post-operation and final follow-up were 3.1 degrees , 5.6 degrees and 7.3 degrees in Group A and 2.3 degrees , 4.2 degrees and 4.4 degrees in Group B respectively. The disc angle at post-operation was larger than that at pre-operation and the difference was significant in Group A (P = 0.049) while not in Group B (P = 0.050). The difference of post-operative disc angle between two groups was not significant (P = 0.231). At final follow-up, the disc angle was a little larger than that of post-operation without a significant difference (P = 0.112, P = 0.855) while Group A had a larger disc angle (P = 0.026). At final follow-up, the occurrence of proximal junctional kyphosis between Groups A and B was not significant (P = 0.235). For adolescent idiopathic thoracolumbar/lumbar scoliosis, in comparison with the anterior approach, the posterior approach using all pedicle screws can achieve a better correction outcome, a less correction loss of coronal Cobb angle and a better disc angle with a longer fusion range.