Statistical Analysis
Data are presented as means and standard deviations unless stated otherwise. Between- and within-group comparisons were carried out using Student’s t test, unpaired and paired respectively. Longitudinal analyses were conducted on all available data using linear mixed-effects models for repeated measures with changes from baseline as dependent variable, surgery group, time and time-by-group interaction as fixed effects and participants as a random effect. Bivariate associations were assessed using Spearman’s rank correlation. Two-sided 