Currently available drugs like steroids or non-steroidal anti-inflammatory agents (e.g. Advil, Aleve) reduce pain but do not address the loss of cartilage behind the osteoarthritis, which is projected to afflict more than 50 million in US alone by 2020.

Cartilage forms the sponge-like, shock-absorbing layers that keep the impact of running and jumping and lifting from grinding bones against each other in joints.

The cell type at the heart of osteoarthritis is the chondrocyte, the cartilage-producing cell responsible for maintaining the integrity of joint cartilage.

Study authors observed that chondrocytes within injured and degenerating cartilage have more PTH type 1 receptors on their surfaces, said an URMC release.

This makes them especially sensitive to the PTH signal that prevents harmful chondrocyte maturation into bone in the joint cartilage. Thus, PTH therapy should increase the cartilage supply exactly where cartilage loss is causing disease.

The study was presented at the annual meeting of the American Society for Bone and Mineral Research in Denver.