Effect of enoxaparin and rivaroxaban on human osteoblast function. Human osteoblast cultures were treated with varying concentrations of enoxaparin and rivaroxaban for 7 days and then analysed for alkaline phosphatase activity. The alkaline phosphatase activity of treatment cultures is expressed as a percentage of untreated controls. Data are presented as the mean ± the standard deviation. *p < 0.05; **p < 0.01 from Student's t-test relative to the control treatment (n = 6).