Johnny Matheny, a former commercial baker from Redhouse, Virginia, lost his left arm to bone cancer in 2008. He now wears a hook-style prosthesis strapped onto his chest; he can laboriously open and close the hook and move the arm up and down by flexing certain muscles. But he is avidly awaiting new technology that he thinks will work much better: a surgically implanted device that attaches directly to bone, potentially enabling superior range of movement and more precise control.
The devices have been tested in people for more than a decade in Europe, but they carry significant risks. Because they require a connection that protrudes through the skin, infections are fairly common, often requiring secondary surgeries. Scientists in Europe and the U.S. are trying to develop ways to better integrate the device with the body—creating stronger connections between metal, bone, and flesh—in order to reduce this risk.