Periprosthetic Atypical Femoral Fractures in Patients on Long-term Bisphosphonates: A Multicenter Retrospective Review.

OBJECTIVES: To define the characteristics of periprosthetic atypical femoral fractures (PAFFs) in patients on long-term bisphosphonate treatment and to provide a guide to the diagnosis and long-term treatment of these patients based on the literature.

DESIGN: Multicenter retrospective review.

SETTING: Fifteen orthopaedic centers in the United States and Canada, including members of the Canadian Orthopaedic Trauma Society.

PATIENTS/PARTICIPANTS: Patients on long-term bisphosphonates who presented with either periprosthetic fractures or femoral fractures, over a 10-year period.

MAIN OUTCOME MEASUREMENTS: Time to union and complications.

RESULTS: Clinically significant differences were identified in time to union, mortality, and complications. There was a statistically significant difference in complications. Imaging review demonstrated identical features in both atypical femoral fractures (AFFs) and PAFFs.

CONCLUSIONS: This is the largest comparative case series reported on PAFFS and AFFs and provides compelling evidence that PAFFs in patients on long-term bisphosphonates are indeed a subset of periprosthetic fractures that exhibit atypical femoral fracture (AFF) characteristics. As such, these fractures pose serious diagnostic and management challenges to trauma and arthroplasty surgeons.

LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.