This is why it takes so long to get over tendon injuries

February 15, 2013
A Danish research team has succeeded in using 50-year-old nuclear weapon testings to reveal surprising news about the human Achilles tendon. Credit: iStock

getting over damage to tendons can be a long and painful process. By combining the nuclear tests of the 1950s with tissue samples and modern technology, a research collaboration between the Aarhus University and University of Copenhagen now reveals why the healing process is so slow.

Many people are affected by injuries caused by straining the Achilles tendon and other in the body. Danish athletes alone account for up to 200,000 injuries per year. This often leads to frustration over the poor treatment options available, and it can take several years to get over tendon damage. The long healing process has always been something of a mystery to medical science because the body's regeneration normally manages to remedy most injuries to . Research results now surprisingly show that the Achilles tendon remains the same throughout adult life. This new knowledge partly reveals why healing following an injury can be a long and painful process, and it opens up for possibilities for seeking new forms of treatment.

"It's fascinating that some parts of the body are designed to last an entire lifetime. The Achilles tendon can withstand very strong forces – up to 500 kg when you're hopping, for example – and you might think that it would be exposed to minor injuries all the time, thus requiring constant repair and renewal. Not the Achilles tendon, however. Its construction is very strong – almost like a steel cable that has to last your whole life. Unfortunately, this 'tendon construction' does not last in a considerable number of cases, as can be testified by Denmark's numerous patients with strained tendons. With our new discovery, we can explain why the healing process can be difficult and take such a long time," explains Katja Heinemeier, Faculty of Health and Medical Sciences, University of Copenhagen.

Inheritance from the Cold War

To find out how quickly the can regenerate, the research group used a somewhat unusual combination of competences – and adopted a positive approach to the many carried out during the Cold War. These nuclear tests took place during the period 1955, and led to a very strong increase in the amount of radioactive carbon-14 in the atmosphere. This increase – called the bomb pulse – reached its peak in 1963, when the amount of carbon-14 doubled compared with the natural level. Since then, it has gradually fallen to the present level, which is almost normal. However, Aarhus physicists can actively use the 'imprint' of the bomb pulse to study the carbon-14 content of materials. This has enabled the research group to find an entry point to what can be called the inheritance from the Cold War nuclear race.

"The changes in atmospheric carbon-14 can be constantly reflected in the human body because we eat plants – and animals fed with plants – that absorb carbon-14 from the atmosphere. In doing so, a kind of history is built up in our tissue. At a later stage, this can tell us about the environment we've lived in, at the same time as precisely showing how quickly the different types of tissue were regenerated. We've studied Achilles tendons from people who lived during the bomb pulse era, and we can conclude that their tendons have retained the very high levels of carbon-14 found during the bomb pulse and for decades afterwards. This can only be explained by the fact that very little renewal takes place in the building blocks of the tendons. Our studies show that the building blocks that made up your Achilles tendons when you were seventeen years old are virtually the same when you're fifty," explains Associate Professor Jan Heinemeier. In addition to being director of the AMS 14C Dating Centre at Aarhus University, he is Katja Heinemeier's father.

Possibility for new forms of treatment

When a tissue has limited renewal of its building blocks – also called slow turnover – it means a poorer in general. Very limited tendon renewal thus provides a good explanation of why are difficult to treat and can often persist for years.

"Based on our results, we actually think that the cells living in the tendon are in a kind of hibernation state, and therefore don't manage to wake up and repair the tendon when it's injured. The interesting results achieved by our research collaboration cutting across different fields of study now form a much better understanding of tendon function. And now that we've found an explanation of why tendons heal so badly, we've got a better chance of developing new ways of treating tendon injuries. A new treatment strategy could involve trying to provoke the dormant tendon cells to wake up and start repairing the tendon, for example. We're about to initiate a study of this possibility," says Professor Michael Kjær, who is head of the Department of Sports Medicine, Bispebjerg Hospital, and is affiliated with the Centre for Healthy Aging, University of Copenhagen.

Explore further: Fallout from nuclear testing shows that the Achilles tendon can't heal itself

Related Stories

Fallout from nuclear testing shows that the Achilles tendon can't heal itself

February 12, 2013
Notorious among athletes and trainers as career killers, Achilles tendon injuries are among the most devastating. Now, by carbon testing tissues exposed to nuclear fallout in post WWII tests, scientists have learned why: ...

New methods enable the early detection of Achilles tendon damage

January 31, 2012
Two biochemical methods, developed at the Centre of Excellence for High Field Magnetic Resonance at the MedUni Vienna by Vladimir Juras from the University Department of Radiodiagnostics, are enabling Achilles tendon damage ...

Scientists discover new clues explaining tendon injury

July 4, 2012
Tendon disorders cost the UK economy more than £7bn a year and now scientists at Queen Mary, University of London have identified a vital component of tendons which could help treat them.

Recommended for you

Exploring the potential of human echolocation

June 25, 2017
People who are visually impaired will often use a cane to feel out their surroundings. With training and practice, people can learn to use the pitch, loudness and timbre of echoes from the cane or other sounds to navigate ...

Team eradicates hepatitis C in 10 patients following lifesaving transplants from infected donors

April 30, 2017
Ten patients at Penn Medicine have been cured of the Hepatitis C virus (HCV) following lifesaving kidney transplants from deceased donors who were infected with the disease. The findings point to new strategies for increasing ...

'bench to bedside to bench': Scientists call for closer basic-clinical collaborations

March 24, 2017
In the era of genome sequencing, it's time to update the old "bench-to-bedside" shorthand for how basic research discoveries inform clinical practice, researchers from The Jackson Laboratory (JAX), National Human Genome Research ...

The ethics of tracking athletes' biometric data

January 18, 2017
(Medical Xpress)—Whether it is a FitBit or a heart rate monitor, biometric technologies have become household devices. Professional sports leagues use some of the most technologically advanced biodata tracking systems to ...

Financial ties between researchers and drug industry linked to positive trial results

January 18, 2017
Financial ties between researchers and companies that make the drugs they are studying are independently associated with positive trial results, suggesting bias in the evidence base, concludes a study published by The BMJ ...

Best of Last Year – The top Medical Xpress articles of 2016

December 23, 2016
(Medical Xpress)—It was a big year for research involving overall health issues, starting with a team led by researchers at the UNC School of Medicine and the National Institutes of Health who unearthed more evidence that ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.