(A–F) Concentrations of bone turnover markers at different stages after severe OVCFs. Levels of bone resorption markers and bone formation markers were still significantly higher than normal levels at the late stage of fracture. Concentrations of N-terminal propeptide of type I collagen (PINP), β-isomerized C-terminal telopeptide (β-CTX), alkaline phosphatase (ALP), calcium, phosphorus, and osteocalcin are expressed by mean±standard error of mean (SEM).