In other words, Michael Franklin will have plenty of business. He's also chief of rheumatology at Abington Memorial Hospital and a board member of the Eastern Pennsylvania chapter of the Arthritis Foundation. Most common is osteoarthritis. No one really knows what causes osteoarthritis. Just as the walls of a house crack and buckle when the foundation shifts, so too the cartilage can become faulty when the underlying bone becomes porous and brittle.
Cartilage is one amazing substance.
To begin with, it's 90 percent water. It's also virtually frictionless. Take an ice cube and slide it across a wet countertop. Cartilage is twice as slippery. Arthritis increases with age, and wear and tear are certainly factors.