Analysis of low-dose estrogen on fracture healing measured by pQCT in postmenopausal women

Background The skeletal disease osteoporosis affects primarily postmenopausal women. It is characterized by increased fracture risk due to defective remodeling of bone tissue and a pathological bone microarchitecture in response to the decreased levels of estrogen. Osteoporosis is clinically silent up until a first fracture occurs. Therefore, the diagnosis of the disease is usually late. Recent preclinical studies with mice, rats and rabbits suggested that estrogen treatment enhances the healing effect after bone fractures. Here we asked whether transdermally applied estrogen, which restores the systemic premenopausal level of estrogen, has a beneficial effect on fracture healing of postmenopausal women as observed in preclinical models. Methods To investigate whether estrogen has a beneficial effect on bone fracture healing of postmenopausal patients, we performed a prospective double-blinded randomized study with 76 patients suffering from distal radius fractures. A total of 31 patients (71.13 years ± 11.99) were treated with estrogen and 45 patients (75.62 years ± 10.47) served as untreated controls. Calculated bone density as well as cortical bone density were determined by peripheral quantitative computed tomography (pQCT) prior to and six weeks after the surgery. Results We found that unlike with preclinical models, bone fracture healing of human patients was not improved in response to estrogen treatment. Furthermore, we observed no dependence between age-dependent bone tissue loss and constant callus formation in the patients. Conclusions Transdermally applied estrogen to postmenopausal women, which results in estrogen levels similar to the systemic level of premenopausal women, has no significant beneficial effect on bone fracture healing.