The long bones in our arms and legs have a layer of smooth, compressible cartilage at each end, which gradually transitions to hard bone underneath. This dual-density combo is known as osteochondral tissue, and when it develops cracks or otherwise gets damaged, conditions such as disabling arthritis can result. Although such injuries frequently afflict athletes, they can occur in pretty much anyone.
For injuries to more uniform types of bone, various scientific institutions have created the previously-mentioned scaffolding. Implanted at the injury site, the three-dimensional material basically provides a roosting site for bone cells, helping them to move in from the adjacent bone and start reproducing. Eventually, they simply take over from the material, replacing it as it harmlessly dissolves.
Now, researchers from the University of Maryland and Houston-based Rice University have developed a version of this material that's tailored to healing osteochondral tissue.