Fracture may influence the serum and urine levels of bone turnover markers, however, the changes in bone markers seem to be not constant. The magnitude of change may be dependent on the size of the fractured bone, the amount of bone involved, and difference in bone markers. In patients with hip fracture, there was early increase in bone resorption markers within 2 weeks after fracture, and resorption markers started to decrease 2-3 months after fracture and stabilized close to prefracture level by about 6 months after fracture. Bone formation markers peaked later than bone resorption markers and remained elevated up to 1 year after fracture. This elevation in bone turnover markers reflects the repair process after fracture, and also immobilization following fracture, bone loss close to the fracture, and post-traumatic systemic reactions contribute to the accelerated bone formation and resorption.