Lot of talk of docs over-prescribing cortisone shots, but it's partly our fault too. We want that tangible, immediate fix--a "cure," rather than months of rehab, weight loss, exercise, lifestyle changes, etc. Hell, I've taken the shot just to get through a performance--and later spent months rehabing that joint to near new. But I don't think a shot every 10 years is causing much damage.

From a scientific/therapy standpoint, the increased arthritis in this case could partly be people continuing the behaviors that sparked the arthritis in the first place--without the usual pain/inflammation, they don't take extra care (OP's comment elsewhere highlights this too).