Recent media headlines may be causing undue concern and confusion among millions of patients who are being treated with bisphosphonates to prevent broken bones. The headlines incorrectly interpret findings of a small pilot study1 which has suggested that bisphosphonates taken to treat osteoporosis may make bones less flexible and more likely to fracture.
IOF President Cyrus Cooper states: “Bisphosphonates have been in clinical use for many years worldwide and are recommended as a first line treatment for the majority of women with post-menopausal osteoporosis. These commonly used drugs have been carefully assessed in numerous and very large research trials which have consistently shown their safety and effectiveness in reducing the risk of breaking a bone.”
The study in question used a novel technique to look at the molecular structure of single bone samples from 30 donors, divided into three groups: those who had never broken a bone; those who had broken a hip and never taken bisphosphonates; and those who had broken a hip and taken bisphosphonates. The researchers found that donors who hadn’t broken a bone had a more flexible bone structure than those with the broken hips. The donors who had taken bisphosphonates appeared to have the lowest bone strength and flexibility of the three groups.
However, the small number of donors, limited clinical information, and inherently compromised design of this preliminary study, make it difficult to draw any direct conclusions. The donors taking bisphosphonates had been prescribed this medication for osteoporosis, indicating that they were already at higher risk of fracture. There was no other information about the two donor groups with a history of broken bones, including their bone density measurements and their risk factors for osteoporosis. Thus it is not possible to know whether the differences in bone structure between these two groups were caused by a difference in their underlying bone health, or if the bisphosphonate treatment also had an effect.
As a result of these limitations, no conclusion should be drawn from this study as to the safety and effectiveness of bisphosphonates in fracture prevention. Much more importantly, many large clinical trials in osteoporosis patients have consistently demonstrated the safety and effectiveness of bisphosphonates in preventing osteoporotic fractures.
Fracture prevention in those at high risk is critically important. Broken bones, especially of the spine and hip, are life-threatening and are a major cause of pain, disability and loss of independence. The results of this small pilot study, for which the conclusions are profoundly limited by study design, do not in any way suggest the need for any change to the use of these medications in clinical practice. It is therefore vital that any patient prescribed a bisphosphonate commence and continue their medication to maximise their chance of preventing a potentially devastating future fracture.
1. Shaocheng Ma, En Lin Goh, Tabitha Tay, Crispin C. Wiles, Oliver Boughton, John H. Churchwell, Yong Wu, Angelo Karunaratne, Rajarshi Bhattacharya, Nick Terrill, Justin P. Cobb, Ulrich Hansen, Richard L. Abel. Nanoscale mechanisms in age-related hip-fractures. Scientific Reports, 2020; 10 (1) DOI: 10.1038/s41598-020-69783-5