Atypical fracture with long-term bisphosphonate therapy is associated with altered cortical composition and reduced fracture resistance [Medical Sciences]
Bisphosphonates are the most widely prescribed pharmacologic treatment for osteoporosis and reduce fracture risk in postmenopausal women by up to 50%. However, in the past decade these drugs have been associated with atypical femoral fractures (AFFs), rare fractures with a transverse, brittle morphology. The unusual fracture morphology suggests that bisphosphonate treatment may impair toughening mechanisms in cortical bone. The objective of this study was to compare the compositional and mechanical properties of bone biopsies from bisphosphonate-treated patients with AFFs to those from patients with typical osteoporotic fractures with and without bisphosphonate treatment. Biopsies of proximal femoral cortical bone adjacent to the fracture site were obtained from postmenopausal women during fracture repair surgery (fracture groups, n = 33) or total hip arthroplasty (nonfracture groups, n = 17). Patients were allocated to five groups based on fracture morphology and history of bisphosphonate treatment [+BIS Atypical: n = 12, BIS duration: 8.2 (3.0) y; +BIS Typical: n = 10, 7.7 (5.0) y; +BIS Nonfx: n = 5, 6.4 (3.5) y; −BIS Typical: n = 11; −BIS Nonfx: n = 12]. Vibrational spectroscopy and nanoindentation showed that tissue from bisphosphonate-treated women with atypical fractures was harder and more mineralized than that from bisphosphonate-treated women with typical osteoporotic fractures. In addition, fracture mechanics measurements showed that tissue from patients treated with bisphosphonates had deficits in fracture toughness, with lower crack-initiation toughness and less crack deflection at osteonal boundaries than that of bisphosphonate-naïve patients. Together, these results suggest a deficit in intrinsic and extrinsic toughening mechanisms, which contribute to AFFs in patients treated with long-term bisphosphonates.
Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.
Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.