## Appendix A
\begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{1}{c}{**Variable**} & **Calculation Method** & **Unit** \\ \hline \multirow{2}{*}{1} & \multirow{2}{*}{Definition of scoliosis—main curve} & Curve with the highest value in degrees on preoperative radiography without traction & Curve 2; \\ \hline \multirow{2}{*}{2} & \multirow{2}{*}{*} & Curve 3 \\ \hline \multirow{2}{*}{2} & \multirow{2}{*}{*} Degree of main curve flexibility & Difference in degrees of preoperative curves with and without traction or lateral tilting & Degrees \\ \hline \multirow{2}{*}{3} & \multirow{2}{*}{*} Degree of secondary curve flexibility & Difference in degrees of preoperative curves with and without traction or lateral tilting & Degrees \\ \hline \multirow{2}{*}{4} & \multirow{2}{*}{*} Main curve flexibility percentage & Difference in degrees of the curve without traction and with traction or lateral tilting, divided by the value of the curve without traction & \% \\ \hline \multirow{2}{*}{5} & \multirow{2}{*}{*} Secondary curve flexibility percentage & Difference in degrees of the sum of the curves without traction and with traction or lateral tilting, divided by the value of the sum of the curves & \% \\ \hline \multirow{2}{*}{6} & \multirow{2}{*}{Main curve flexibility} & Flexibility percentage equal to or greater than 40\%, flexible; flexibility percentage less than 40\%, nonflexible & Flexible; \\ \hline \multirow{2}{*}{7} & Secondary curve flexibility & Flexibility percentage equal to or greater than 40\%, flexible; flexibility percentage less than 40\%, nonflexible & Flexible; \\ \hline \multirow{2}{*}{8} & \multirow{2}{*}{* Degree of main curve correction} & Difference in degrees of the curve without traction between pre- and postoperatively & Degrees \\ \hline \multirow{2}{*}{9} & \multirow{2}{*}{*} Percentage of main curve correction & Percentage of correction achieved through dividing the difference between the pre- and postoperative curves (degrees) by the preoperative value & \% \\ \hline \multirow{2}{*}{10} & \multirow{2}{*}{*} Degree of secondary curve correction & Difference in degrees of the curve without traction between pre- and postoperatively & Degrees \\ \hline \multirow{2}{*}{11} & \multirow{2}{*}{*} Percentage of secondary curve correction & Percentage of correction achieved through dividing the difference between the pre- and postoperative curves (degrees) by the preoperative value & \% \\ \hline \multirow{2}{*}{12} & \multirow{2}{*}{Normal-range preoperative pelvic obliquity} & Preoperative pelvic obliquity equal to zero & Yes; \\ \cline{3-4}  & & No \\ \hline \multirow{2}{*}{13} & \multirow{2}{*}{Normal-range postoperative pelvic obliquity} & Percentage pelvic obliquity equal to zero & Yes; \\ \cline{3-4}  & & No \\ \hline \multirow{2}{*}{14} & Comparison of pre- and postoperative & Comparison between qualitative variables 12 and 13 & \\ \cline{3-4}  & normal-range pelvic obliquity & Difference in degree of pelvic obliquity between pre- and postoperative & Degrees \\ \hline \multirow{2}{*}{15} & \multirow{2}{*}{*} Preference between pre- and postoperative & Percentage of correction achieved through dividing the difference between pre- and postoperative & \% \\ \cline{3-4}  & pelvic obliquity & values & \\ \hline \multirow{2}{*}{16} & \multirow{2}{*}{*} Percentage of pelvic obliquity correction & Percentage of correction achieved through dividing the difference between pre- and postoperative & \% \\ \cline{3-4}  & & No \\ \hline \multirow{2}{*}{17} & \multirow{2}{*}{*} Difference between pre- and postoperative & Difference in degrees of postoperative and preoperative kybosis & Degrees \\ \cline{3-4}  & kybosis & Percentage of correction achieved through dividing the difference between & \% \\ \cline{3-4}  & & Pre- and postoperative kybosis by the preoperative value & \\ \hline \multirow{2}{*}{19} & \multirow{2}{*}{*} Difference between pre- and postoperative & Difference in degrees of postoperative and preoperative lumbar lordosis & Degrees \\ \cline{3-4}  & & No \\ \hline \multirow{2}{*}{20} & \multirow{2}{*}{*} Percent correction of lumbar lordosis & Percentage of correction achieved through dividing the difference between pre- and postoperative lumbar lordosis by the preoperative value & \% \\ \hline \hline \end{tabular}
\end{table}