Although there is strong evidence that bisphosphonates prevent certain types of osteoporotic fractures, there are concerns that these medications may be associated with rare atypical femoral fractures (AFF). But the relationship between long-term bisphosphonate treatment and AFF is unclear. In this study, the investigators would like to analyze the long term effects on femur by bisphosphonate treatment.The participants are treated in the investigators hospital more than four years.

Bisphosphonates have been widely used in the treatment of osteoporosis. Recently, long-term use of bisphosphonates increases the risk for AFFs in older women, according to the results of a population-based, nested case-control study. Unique radiographic pattern of AFF is reported, such as simple transverse or short oblique fracture with breaking of medial cortex and cortical thickness. But radiographic evaluation were performed for fracture patients in previous reports and the femoral condition of long-term bisphosphonate treatment patients before fracture is not known.

The main objective of this study is to reveal the effects of long-term bisphosphonate treatment on femur.

Inclusion Criteria:

• Patients using bisphosphonate more than four years

Exclusion Criteria:

• patients who could not use bisphosphonate

Oateoporosis patients using bisphosphonate more than four years.