The biggest issue with existing hip replacements is that they are actually too rigid and tend to take some of the stress off of living bone, which causes it to weaken and deteriorate. Over time, this leads to painful joints and eventually the need for a second hip replacement -- which can be difficult if there's no living bone left for the artificial joint to graft on to. In much the same way that 3D-printed "dough" can encourage bones to heal, Pasini's design helps the body heal itself.

"So because the implant loosely mimics the cellular structure of the porous part of the surrounding femur, it can 'trick' the living bone into keeping on working and staying alive," Pasini explained. "This means that our implant avoids many of the problems associated with those in current use."

While the new hip replacements aren't the most dramatic 3D-printed bone replacements we've seen, they will work with existing hip replacement techniques so surgeons won't need to undergo any additional training when they start putting these to use in the next three to five years. And, assuming Pasini's research holds true, they'll also lead to fewer complications in the long run.