Mattress toppers only change the firmness level of the mattress’s comfort layer. To be truly orthopedic, your mattress needs to support you all the way from the base layer to the top layer. That means you can’t toss a topper on any old innerspring or foam mattress and expect it to be orthopedic. Adding a quality topper can help improve your mattress’s support and cushioning, but it won’t make your mattress orthopedic.