Imperial College researchers have developed a low-cost, easy-to-manufacture stabiliser for broken bones in place with metal pins or screws attached to a surrounding metal frame.
When soft tissue is severely damaged together with bone, external fixators are the initial step in keeping fractures in legs and arms in place before an operation to definitively fix the broken bones. However, their cost and low availability in many regions resulting in many people using homemade or low-quality fixators that could lead to serious complications or improper healing.
An Imperial College team have developed an external fixator, which is being tested in Gaza and Sri Lanka, and since the invasion of Ukraine, more than 500 fixators have been manufactured in Poland to help with the crisis.
The details of the tool can be found in Frontiers in Medical Technology.
Fixing broken bones without the price tag
The device is low-cost and has a lightweight design that can be manufactured locally to international standards. The design and toolkit allows repeated precise manufacture of the fixator anywhere in the world, including in the least developed countries.
The device is currently being tested in Sri Lanka for road traffic accidents which cause around 70% of fractures in low- and middle-income countries (LMICs). In Ukraine and Gaza, both regions face unpredictable demand and supply of such devices, it is being used for gunshot wounds and other conflict trauma.
Lead researcher Dr Mehdi Saeidi, from the Department of Bioengineering at Imperial, said: “We have managed to develop an external fixator that is one-tenth of the cost of commercial devices but with similar performance. This device can provide surge capacity for conflict zones or in response to unpredictable incidents and situations, which was the case with the war in Ukraine.”
The fixator is made of four clamping systems and a road, which can be manufactured using stainless steel and aluminium, two readily available materials. The device also can be manufactured using milling and turning.
Initially, the researchers found that due to the precision of the parts, the device would need to be built by a highly skilled operator or using advanced machinery. Therefore, Dr Saeidi developed a manufacturing toolkit with components such as drill bits, a saw and cutting guides to make the process easier, faster and reproducible.
The fixator was then tested in cadaver leg bones, showing it had similar stiffness to commercial devices.
Trialling the device in three countries
The broken bones device is now being trialled in three countries. The device was originally created to increase supply in Sri Lanka. In Gaza, in collaboration with Professor Ghassan Abu-Sitt at the American University of Beirut, the device is being trialled with gunshot wounds. The trial is also assessing the ability of the external fixator to be cleaned, sterilised and reused.
Professor Abu-Sittah said: “In previous wars hospitals in Gaza had run out of external fixators, which jeopardised patient care. Developing the capacity to manufacture fixators locally means that this will not happen again.”
Furthermore, as a result of the Ukraine conflict, Imperial’s Professor Anthony Bull was approached by surgeons in Poland who urgently needed such fixators, resulting in more than 500 of the devices being manufactured for use in Ukraine. The drawings provided freely on Imperial’s website were all that was needed by the engineers.
Professor Jonathan Jeffers, one of the study investigators from the Department of Mechanical Engineering at Imperial, said: “This work, conceived years ago based on needs identified by our military and civilian trauma surgeons, shows how basic engineering can mitigate suffering in the most dreadful of situations. The Ukraine situation is exactly why this project was conceived and demonstrates the ability to respond to surge demand.”
