Forty-three patients were randomly allocated to undergo either trapeziectomy alone (control) or with a ligament reconstruction and tendon interposition (LRTI) using an abductor pollicis longus tendon slip. The patients were reviewed at a median 13 (range, 7-29) months after surgery. The demographic characteristics, severity of disease and pre-operative clinical measurements of the two study groups were indistinguishable but LRTI lengthened the operation by approximately 15 minutes. Both groups expressed equal satisfaction with the operation and there were no significant differences between the two treatment groups. Simple trapeziectomy is an effective operation for osteoarthrosis at the base of the thumb and the addition of a ligament reconstruction was not shown to confer any additional benefit.