BIRMINGHAM, AL – Long-term use of bisphosphonates have been associated in some research with subtrochanteric femoral shaft fractures after little or no trauma, but new research looking at VA data did not replicate that effect.
In fact, the study published recently in the Journal of Clinical Rheumatology, indicated that nontraumatic subtrochanteric (NTST) femoral fractures were uncommon, and longer bisphosphonate use was associated with lower, not higher, risk.1
For the retrospective cohort study, University of Alabama at Birmingham researchers used 1998-2007 VHA electronic medical records data on 78,155 veterans who had a fragility fracture at age 45 years or older; mean age was 66.5, but 32.5% of the participants were 75 or older at first fracture. The research examined associations of bisphosphonates with risk of NTST femoral fracture and, separately, hip fracture, controlling for sociodemographics, medications and comorbid medical conditions.
Observing 69.3% for six or more years, only 11.8% were prescribed bisphosphonates. During follow-up, 408 had an NTST femoral second fracture, and 1,584 had a hip second fracture, according to the report.
Compared with those never on bisphosphonates, the adjusted hazard ratio for NTST femoral second fracture among patients on four years of therapy or longer was 0.40 and for hip second fracture was 0.38, the authors reported.
“Bisphosphonate treatment in this high-risk cohort was infrequent with few long-term users, limiting power to assess long-term effects,” the authors wrote. “In men, risks of NTST femoral fractures associated with bisphosphonate treatment may be low in contrast to substantial protective benefits for hip fracture.”
1 Safford MM, Barasch A, Curtis JR, Outman R, Saag K. Bisphosphonates and hip and nontraumatic subtrochanteric femoral fractures in the Veterans Health Administration. J Clin Rheumatol. 2014 Oct;20(7):357-62. doi:10.1097/RHU.0000000000000170. PubMed PMID: 25275761