By Charlotte King
The healing of bone fractures could be improved using tiny sensors that are strapped on the metal healing plate to measure the change in weight on the sensor as the bone heals.
Bad fracture healing
Currently it is very difficult for doctors to monitor the healing of fractures. A lot of it is done by guesswork and, as such, around one in 10 do not properly heal due to wrong guesses. Without re-opening the wound every time it is impossible to tell whether a break is healing correctly.
The model here shows the wood bending as bone does if it is fractured
Biosensors
So scientists at Bilkent University in Ankara, Turkey, are working on many nanotechnology projects, including tiny wireless sensors that will get placed across a fracture to monitor how a fracture is healing.
The sensors could, in future, be planted on the metal plate placed on the bone where the fracture is. It would monitor the change in stress on the break from the body weight above. The sensors currently in development use low frequency waves that pass through them to a monitor near to the sensor, to survey the stress on the plate.
As the bone heals, the stress on the plate decreases, so decreasing stress over time means healing over time. If there is no decrease, the bone is not healing. So this could be a non-obtrusive way to monitor the healing of bones.
Emre ünal, who is working on the biosensor project at Bilkent says “the motivation for this project was that there is no such wireless bio-implant, chip-scale device. You can look at the resonance frequency to monitor strain changes on the chip. Doctors currently have to guess if a fracture has healed or not”.
Sheep
Bilkent’s colleagues at the National Institute of Health, USA, have tested the latest model of the biosensors on real sheep metatarsal and have demonstrated proof of concept.
The next stage will be to try the sensor on a live sheep which should show real healing over time.