Bob, osteoarthritis is not the same as Dupuytren's contracture. I presume CMC stands for "carpo-metacarpal" which just describes the location of the arthritis: at the joint between the carpal (wrist) bones and the metacarpal bone (the metacarpals are the five bones that make up your hand, between the wrist bones and the phalanges (finger bones). It sounds like you may have two different problems at that joint.

Sorry, you can't use Dupuytren's in scrabble: it's a proper name! But I won't tell Judy...

Aloha,
Mark