What is the incidence rate of atypical femur fractures in women on bisphosphonates after 2-3 years?

The incidence rate of atypical femur fractures in women on bisphosphonates after 2-3 years is generally estimated to be about 1 in 1000. This statistic reflects the increased risk associated with the long-term use of bisphosphonates, medications commonly prescribed for osteoporosis to reduce the risk of fractures.

Atypical femur fractures are a rare but recognized side effect of bisphosphonate therapy. Studies have demonstrated that while bisphosphonates are effective in reducing the overall rate of hip and other common fractures, a small subset of patients may experience atypical fractures, particularly after prolonged use. The reported incidence rate serves as a reminder for healthcare providers to monitor patients on these medications for any unusual bone pain or signs that might indicate an atypical fracture, especially in those who have been on treatment for several years.

The other options provide incidence rates that do not align with current findings in the medical literature regarding this specific effect of bisphosphonates. Thus, 1 in 1000 is the most accurate reflection of the risk.