An observational study in Atypical Femur Fracture, sponsored by University Health Network, Toronto. Active, not recruiting at 3 sites in Canada. Open to female participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-11.
Sponsored by University Health Network, Toronto · Observational
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.
Antiresorptive therapy (ART) drugs are effective osteoporosis treatment and help decrease osteoporosis-related fractures. However, their long-term use has been associated with rare but serious atypical femur fractures (AFFs). Fear of these side effects has caused a substantial decline in the use of these effective drugs and rising fracture rates. The investigators propose to compare 330 cases of people with AFFs to 660 matched controls to explore similarities and differences in (1) clinical findings, such as type of ART and length of use, prior fracture, bone density, femur geometry, etc., and (2) genetic variants, and then (3) to validate the top few genetic variants to see if they are indeed present in an additional group of 100 AFF patients and not present in 100 control subjects. This study will determine clinical and genetic risk factors for these debilitating atypical fractures such that at-risk patients in the future can be treated differently to avoid them.
University Health Network, Toronto is the lead sponsor of 1,411 studies on the registry; 292 are open to participants now.
Of its 17 completed or terminated interventional studies of FDA-regulated products, 3 (18%) have results posted.
Counted across the registry records on this site, refreshed daily.
Community based population in Ontario and British Columbia Canada
Exclusion Criteria:
-
Atypical Femur fracture cases
Other: No Intervention
matched to AFF cases by race, age, length of ART use
Other: No Intervention
No Intervention
Associations between AFF and clinical Risk Factor
Associations between AFFs and clinical risk factors
Time frame: baseline
Associations between AFF and common genetic variants
Associations of common genetic variants among patients with AFFs
Time frame: baseline
Validation of top genetic variants
To validate the top few genetic variants identified in the above case-control study in a separate cohort of 100 cases and 100 controls.
Time frame: baseline
Plan to share: Undecided
No publications or documents are linked to this record.
This study is active, not recruiting, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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University Health Network, Toronto