Metal titanium screws are commonly used to treat bone fractures, but they often have to be removed once the bone heals due to potential side effects. Researchers from the Fraunhofer Institute for Manufacturing Technology and Advanced Materials, university hospitals of Giessen-Marburg and Bonn, and the University of Bremen have designed ceramic screw nails to stay implanted permanently, avoiding the trouble, anguish, and costs associated with follow-up surgeries.
Dubbed scrails, because they work as both screws and nails, the implants are made of calcium phosphate. This material is very similar to bone and is biocompatible with it. While the scrails have a helical exterior, they’re designed to be hammered-in like regular nails. As they’re pounded in, they naturally rotate and drive themselves into bone.
Once inside the bone, the scrails integrate with surrounding bone tissue and stay there forever. They can continue providing the necessary structural support without disintegrating like polymer screws would. Since metal and polymer screws eventually have to be removed or disappear on their own, their absence often leaves an empty cavity that can lead to cracks.
Calcium phosphate is already well studied for biocompatibility and used in medical implants. The new scrails have been tested on sheep and the researchers showed that these can be hammered in much more precisely and faster than bone screws, allowing for faster procedure, potentially easier recovery, and cost savings for everyone paying.