I just went in for a six-month check up after getting a new knee joint. The doctor took an X-ray that showed the bone with the new joint implant. I know the implant is made of plastic but it looked like a cartoon drawing on the X-ray. How do they get a picture like that?

Ah, the amazing wonders of modern technology. X-rays haven’t changed much, but the new computer software and digitized photography makes it all possible. Not only does the
program show where the implant is located, it separates it from the bone and soft tissues around it while also analyzing its position.

So a two-dimensional picture can show how much slide and glide occurs in the joint as well as how much rotation or twisting occurs. It’s possible to compare the movement of the implant with known “normal” movements in knees without an implant. This helps
researchers find out which implant works the best for each type of knee patient.