The change in dorsal angulation, radial angulation and axial compression from admission to 12 months and from 10 days to 1 month, respectively, were calculated. The power calculation was based on the change in dorsal angulation from admission to 12 months. The study was designed for demonstrating a difference in dorsal angulation between the groups of 0.5 standard deviation, which is often referred to as a medium-sized standardised effect [36]. We assumed that the standard deviation for the change in dorsal angulation from admission to 12 months was 10°, and the study was powered to detect a difference between the groups of 5°, which is our estimation of a clinically relevant difference between the groups. For a 5% significance level and a power of 80%, a sample size of 63 patients in each group was needed.