Clinical Research Directory

Evaluation of IVA (SE Femur Scans) to Identify Incomplete AFFs

DXA scanners are routinely used to assess bone mineral density (BMD) and fracture risk in osteoporosis patients. They provide detailed bone imaging in a low radiation setting. Hologic manufactures scanners that are able to perform high definition instant vertebral fracture assessment (HD-IVA) used to screen at-risk patients for asymptomatic spine fractures instantly and reliably at the same time they are having their yearly BMD. We wish to investigate whether this same proven technology (HD-IVA scan mode) used on femurs (the scan mode is now called SE Femur scans) can be used to screen for atypical fractures of the femur in patients at risk for these debilitating fractures. In this proof of concept study, we propose to examine whether DXA scanners can provide a sensitive low radiation screening method to identify incomplete AFFs in patients with known incomplete AFFs and in patients at risk.

Quebec Registry for Atypical Femur Fractures

Bisphosphonates are recommended as first-line agents to reduce fracture risk in patients with osteoporosis and have in general an excellent safety profile. However, recent reports have noted that prolonged use of bisphosphonates may be associated with rare but serious adverse effects, namely atypical femur fractures (AFF), an atraumatic subset of subtrochanteric and diaphyseal fractures. The overarching aim of this project is to contribute to the characterization of clinical, biomechanical, radiological and genetic predictors of AFF, associated or not with bisphosphonate and-or denosumab therapy. AFF arise on the lateral (external) aspect of the subtrochanteric and diaphyseal regions of the femur, regions subjected to high mechanical loads. Because of this unique distribution, the investigators hypothesis is that patients with AFF demonstrate specific geometrical variations of their femur whereby baseline tensile forces applied to the lateral cortex are higher and might favour the appearance of these rare stress fractures. Measurements to investigate these geometric variations with be calculated from 3D images reconstructed using scans procured using the EOS® low irradiation 2D-3D X-Ray scanner.

Personalizing Osteoporosis Care: Clinical & Genetic Risk Factors for AFFs

The overall objective of this project is to identify clinical and genetic risk factors for Atypical Femur Fractures (AFFs) in Anti-resorptive therapy (ART) users by conducting a case control study of 330 cases of AFFs and 660 controls without AFFs matched for age, sex, race and duration of ART.

Atypical Fracture Cohort Study

Osteoporosis is a disease characterized by increased bone fragility and deteriorating bone micro-architecture. The main consequence of osteoporosis is low-trauma fractures, most often of the hip, spine and wrist. Recently, another type of low-trauma fracture, atypical femur fractures (AFFs), have received much attention. Little is known of the cause of these debilitating fractures; however, they have been associated with long term bisphosphonate use. What we currently know about AFFs is based on case reports or small case series, or studies using administrative databases or secondary analyses of bisphosphonate trials. While these reports provide some preliminary information on the relationship between long term bisphosphonate exposure and AFFs, detailed clinical data are absent. As we have established a network of specialists across southern Ontario our group is in a position to collect meaningful information on a larger group of patients who have experienced these debilitating fractures into a centralized AFF registry.