Previous studies have also shown that persons with DS have decreased bone density, which increases the risk of fractures. Researchers also thought that individuals with DS might have a distinct healing response to fractures.
“But to discover that fractures in DS would not heal was incredible. Scientists have been studying fractures for a long time in a lot of different species, and while healing might be slow in some cases, most fractures do eventually heal in all species. In our research, the fractures didn’t heal at all. When bones heal, a soft callous made of cartilage, a sort of glue, will form on the bones and then connect the fractured ends back together; we call this bridging. In Down syndrome models, the glue starts to form, but it’s never able to bridge,” said Kirby Sherman, a PhD candidate in the VMBS’ Department of Veterinary Physiology & Pharmacology (VTPP).
The researchers claim this is alarming because a fracture that does not fully mend can have disastrous health effects. This can be worse for people with DS due to severe bone density loss.
“Based on this, the risk of fractures is a major health concern for the Down syndrome community. A fracture not healing properly, what we call a non-union, can kill people, whether they have Down syndrome or not,” Sherman said.
“If this population really has a higher rate of non-union than the normal population, that’s a big deal,” said Dr Larry Suva, VTPP department head.
Non-healing Fractures in Down Syndrome go unnoticed?
The researchers state that there are two main explanations for why this problem has gone unnoticed up to this point. Firstly, people with DS are living far longer than they used to.
People with DS only had a 10-year life expectancy in 1960, according to the Centers for Disease Control and Prevention (CDC). By 2007, the life expectancy has grown to 47 years as more knowledge and techniques were discovered and used to counteract the endocrine effects of DS.
“We’ve known that bone mass is lower in this population, and the increased life expectancy of this population has allowed researchers to better understand the long-term implications of their lower bone mass. Today, there are people with DS in their 20s and 30s who have bone mass and bone architecture consistent with someone in their 60s. They’re active members of the community and they’re playing sports. Obviously, that’s great, but if they’re at increased risk of bone fractures that won’t heal, it’s also a concern,” said Suva.
The second reason this problem went unnoticed for so long is that doctors and hospitals did not consider providing specialized treatment for patients with Down syndrome. Hence, there was no easily available data to identify this problem.
“There’s not a medical code that identifies people with Down syndrome, so researchers have not had any kind of database they could use to gather statistics that support this kind of research. Down syndrome support groups and family members don’t want their loved ones or themselves singled out for having a disease. After all, they’re normal people. As a result, even with all of the fractures that get recorded every day in the United States, there’s no way to identify which of those patients have Down syndrome and, therefore, no organized way to track their healing,” said Suva.
Future Implications of the Research Findings
The next steps will involve looking for such human data and concentrating on the actual barriers to fracture healing. Nobody was looking for solutions since no one knew there was an issue.
The researchers anticipate that due to the latest findings people with DS will be given special consideration when it comes to bone health. Also, bone strengthening procedures will be adopted more widely and fractures will be monitored more carefully.
“We want physicians to say to patients, ‘you’re 17 years old; you can keep playing soccer and being active. But we also want them to make sure these patients’ diet and vitamin D levels are good, to do all these things that are suggested for skeletal health. That’s our goal,” said Suva.