We compared 84 patients with the Ivory trapeziometacarpal prosthesis versus 62 with ligament reconstruction and tendon interposition arthroplasty performed for osteoarthritis. There were 134 women and 12 men with a mean age of 60 years. Prospective clinical assessment was made using the Quick Disability of the Arm, Shoulder and Hand (DASH) questionnaire, visual analogue scale for pain, range of motion, and grip and pinch strength. The mean follow-up was 4 years (range 2–5). Prosthetic replacement provided significantly better thumb abduction, adduction, pinch strength, QuickDASH, pain relief, satisfaction and a faster return to daily activities and previous work. Revision surgery was required for two patients in the prosthesis group, two for dislocation and one cup loosening, while in the ligament reconstruction group there were no revisions. We conclude that trapeziometacarpal prosthesis provides better mid-term results in terms of function compared with ligament reconstruction and tendon interposition for patients with Stages 2 and 3 osteoarthritis of the trapeziometacarpal joint. Level of evidence: II