Statistical Analysis
TKA
As described previously, 23 patients were needed in each group to detect a difference between groups beyond the 0.13 mm measurement error of the MTPM with a power of 80% and an alpha of 0.05The MTPM was compared between the TKA groups using a linear mixed-effects model (LMM), which effectively deals with missing values during follow-up or when patients withdraw from the study (e.g., due to revision); it also takes within-subject correlation into account. The model consisted of a group variable (cementless or cemented TKA implants), a time variable, and an interaction term between time and group. A random-intercept term was used, and any remaining variability was modeled with a heterogeneous autoregressive order-1 covariance structure. Given its non-normal distribution, the main outcome of MTPM was log-transformed and computed as log