Statistical analysis
For continuous variables with parametric and non-parametric distribution, means (with standard deviations [SDs]) and medians (with interquartile ranges [IQR]) were calculated. Definite values of pre- and postoperative tibial obliquity were calculated as means of the two mean measurements obtained by the two investigators. T-tests were used to assess differences in continuous variables between groups. To assess changes in continuous variables for more than two groups, Kruskal–Wallis tests were used. Changes in tibial obliquity (based on the MPTA) from pre- to postoperative were grouped into I. restoration of tibial obliquity, II. change 0°–1°, III. change 1°–2°, and IV. change > 2°.Differences in tibial obliquity depending on treatment group were compared with chi-squared tests. Intraclass correlation coefficients (ICCs) between the reviewers were calculated for the two measurements. A-priori sample size calculation with a 