The principle hypothesis is that treating osteoarthritis at the carpometacarpophalangeal (CMC) joint with injectable hyaluronan will results in greater pain relief, higher patient satisfaction, and better functional outcomes than treating with placebo injections (local anesthetic) or with corticosteroid injections. Treating CMC osteoarthritis with corticosteroid injections will result in greater pain relief, higher patient satisfaction, and better functional outcomes than treating with placebo injections. Patients with worse pre-treatment function will have less improvement and worse post-treatment results after administration of corticosteroid or hyaluronan.