Small implant for filigree bone
© University of Rostock
„When there is glaze outside, it can happen that within one hour five to ten patients with radius fractures near the wrist have to be treated”, says Dr. Georg Gradl, assistant medical director in the department for trauma and reconstructive surgery at the University of Rostock, Germany. This is due to an important human reflex, which causes the hands to thrust out protectively when the body is falling. However, sometimes the fine radius can just not withstand the blow.
The last five years, plates and screws have been used to treat these fractures. In doing so, the panels, made out of a titanium alloy, are put on top of the bone. The screws are twisted through pre-cut holes, so that everything is pressed tightly to the radius. This may be disadvantageous for patients suffering from osteoporosis: The heavy pressure to the surface can lead to alterations of the bone structure underneath the plate. And as the plate is located outside of the bone, it touches sinews and nerves. This may also cause irritations.
In order to get the plates to the bone wide cuts are necessary. This is one of the reasons why Gradl wanted to develop a new implant: “You treat fractures, see the time and effort, and think to yourself: how can this be improved”. Thus, the idea of Targon DR was born – a filigree implant, which can be sunk into the bone instead of being located on top of it.
The task of the physicians, then, was to find out what size the metallic panel should have and which form would be the best to fix these special fractures. Therefore, the scientists took patients’ computed tomography shootings and calculated an average value, a “typical” radius fracture near the wrist, with which the implant should comply. The result is a gently swung nail, about five centimetres long and three millimetres wide.
The filigree implant is so tiny, that small cuts are sufficient to get it to the radius. On location, the implant is inserted into the bone lengthwise and thus stabilises the breakage. And since the nail is not placed upon the bone, sinews and nerves are not disturbed. “The patient doesn’t notice the implant at all”, Gradl explains.
Until now Targon DR has been applied 35 times to treat radius fractures near the wrist. A study to test the effectiveness of the invention is still underway. First insights indicate “a trend to an earlier anastasis”, according to Gradl.