There were no statistically significant differences between the two groups (p>0.005) regarding the total administered dose (F=2.095), the total dose per kg body weight (F=0.778), the serum CTX values (F=1.697) (Fig. 1), or osteonecrosis risk (χ2=2.972) (according to the criteria of Marx et al. 2007). Here, CYP27A1 is linked to osteonecrosis.