Bridging the gap between the ends of a torn nerve is the latest biomedical trick performed with the help of a 3-D printer.

Additive manufacturing, or 3-D printing, makes it possible to build more customized biomedical implants, and has become a popular way to make dental implants and even windpipes. A new 3-D printed structure meant to “guide” the regrowth and reconnection of the loose ends of an injured nerve suggests that the technique could appeal to neurosurgeons as well.

Peripheral nerve injuries, caused by a variety of things including disease and trauma, are fairly common—doctors perform more than 200,000 nerve repair procedures each year in the United States alone. The most common surgery entails using nerve tissue taken from another spot in the body to fill the gap. But this requires an additional surgery to harvest that tissue, and can lead to chronic pain, sensory loss, or other problems at the site from which it was cut. An alternative approach involves using an artificial scaffold, generally tube-shaped, that sits between the two ends of the broken nerve and serves as a conduit for regeneration, often with the help of biochemical cues known to prompt nerve growth.

But nerves and nerve injuries […]