Influence of different surgical approaches on the changes of the interspace angle in adolescent idiopathic thoracolumbar/lumbar scoliosis

Objectives To evaluate the different influences on the interspace angle changes after anterior or posterior correction and fusion in adolescent idiopathic thoracolumbar/lumbar scoliosis.Methods By reviewing the medical records and roentgenograms of adolescent idiopathic thoracolumbar/lumbar scoliosis patients underwent anterior(Group A) or posterior(Group B)correction and instrumentation,Cobb angle of the curve,correction rate,and interspace angle were measured and analyzed.Results There were 30 patients in group A,and 12 patients in group B.The mean preoperative and post-operative coronal Cobb angles of the main curve in group A and group B were 48.9 and 11.7,44.3 and 5.3,respectively,with an average correction rate of 76.1%and 87.7%.At the final follow-up,the coronal Cobb angles in the two groups were 18.1 and 7.7,respectively.The interspace angles before operation,after operation and at final follow-up were 3.2,5.6 and 8.2 in group A,and 3.3,3.6 and 3.2 in group B,respectively.Between the 2 groups, the coronal Cobb angle after operation,correction rate,coronal Cobb angle at final follow-up,coronal Cobb angle loss of the main curve in group B were all better than that in group A(P =0.022,P =0.022,P =0.005,P=0.O19).The difference of the interspace angle after operation was not sifgnificant(P = 0.068),while at final follow-up,group A had a larger interspace angle(P = 0.001)and a greater loss of the interspace angle(P = 0.043).Conclusions For adolescent idiopathic thoracolumbar/lumbar scoliosis,compared to anterior approach,posterior approach using all pediele screws obtains a better interspace angle with a less interspace angle loss upon final follow-up.