Disentangling the Emerging Evidence around Atypical Fractures

Abstract

Atypical femur fractures are rare but a growing concern, as they are more common in patients who use bisphosphonates. The best radiology-based studies have had access to only short-term exposure data, while the studies using prescription databases with substantial long-term data did not have access to radiology reports. The interests of the patients are probably best served by reserving long-term bisphosphonate treatment for patients who are at the highest risk of osteoporotic fractures and considering drug holidays after 5 years in patients at low risk. Recent studies have further strengthened the case for active medical or surgical therapy in patients with incomplete fractures, but patient numbers are small, and randomized controlled trials may not be forthcoming in the immediate future. The recommendations made to establish an international database for such fractures have not yet been followed, and more epidemiologic and pathophysiologic research is needed.

Atypical Femoral Fractures in a Patient with Continuous Decreasing BMD after Only 1.5 Years of Bisphosphonate Treatment

“…BMD is maintained or increased if the bone had positive response to bisphosphonate [21]. Drug holiday is suggested in the "low risk osteoporotic fracture group" patients with improvement of BMD to normal or osteopenia range, no further fracture history, and good adherence to bisphosphonate for at least 2 years [22,23].…”

Questioning the association between bisphosphonates and atypical femoral fractures

“…The study can be criticized for its unbalanced risk factors applied between groups. Furthermore, the risk may have been inflated owing to lower mortality among bisphosphonate users …”