Patients with brittle bone disease who were given treatments to boost their bone density experienced a similar number of fractures as those who received standard care.
The findings challenge the long-held belief that better bone density could help those with the condition and suggest treatment strategies should instead focus on improving bone quality, experts say.
Fragile bones
Brittle bone disease, or osteogenesis imperfecta (OI), is caused by a defect in collagen production – a protein essential for bone structure – leading to weak, fragile bones that can break with little or no trauma. It affects around 1 in every 15,000 people.
For decades, treatment of the condition has focused on giving drugs that increase bone density, even though there is little evidence that this reduces fracture risk.
Continued fractures
Scientists at the University of Edinburgh followed 350 adults with OI over eight years, from May 2017 to March 2025, in the TOPaZ trial. Half of the patients received drug treatments designed to improve bone density, while the remaining half received standard care.
While those on the drug treatment had significantly increased bone density compared to those receiving standard care, this did not lead to a reduction in the total number of new fractures, or fractures in the spine.
37 per cent of those who received bone density treatment experienced fractures, compared with 36 per cent of those who received standard care.
Better treatments
The findings could help to re-shape treatment approaches for OI, moving towards therapies that strengthen bone quality to limit disease progression and improve outcomes for patients, experts say.