ASBMR task force AFF 2014

Atypical subtrochanteric and diaphyseal femoral fractures: second report of a task force of the American Society for Bone and Mineral Research

Shane E, Burr D, Abrahamsen B, et al. Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research 2014 · PMID 23712442 · doi:10.1002/jbmr.1998

Question

How should atypical femoral fractures be defined, and what is known about their pathogenesis and management?

Design

Expert task force report with systematic review of the evidence and a revised case definition.

Patients

Patients with subtrochanteric and femoral shaft fractures, particularly long-term bisphosphonate and denosumab users.

Intervention

Revised major and minor diagnostic criteria

Comparison

The 2010 task force case definition

Primary outcome

Consensus case definition and management recommendations

Key result

Concluded that atypical femoral fractures behave as stress or insufficiency fractures and revised the case definition: transverse orientation was emphasised, minimal comminution was now allowed, localised periosteal stress reaction became a major feature, and drug and disease associations were removed from the criteria. The relative risk with bisphosphonates is high but the absolute risk is low, rising with long-term use and appearing to fall after the drug is stopped.

Limitations

Consensus document rather than primary evidence; the evidence base for medical and surgical management was limited.

Impact on practice

The standard diagnostic definition used in exams and clinic; in practice, suspect an AFF in a long-term antiresorptive user with thigh pain, stop the drug and image both femurs, as risk appears to fall after withdrawal.