Forty patients (156 metacarpophalangeal joints) with mutilating rheumatoid arthritis were randomly allocated in a blinded manner to have either NeuFlex or Sutter implants. Indications for operation were pain and severe deformity. Thirty-nine patients were followed up postoperatively for one year. An independent physiotherapist and occupational therapist examined each one. Grip strength, range of motion, and pain during activity and at rest were measured. The Canadian Occupational Performance Measure (COPM) assessed the patients' evaluation of their occupational performance. Both groups had overall good results, but it seems that though patients' mobility and grip strength improve considerably, pain seems to do so only relatively. Most patients seem to be satisfied with the operation and their functional gain. Five out of 78 Sutter and two out of 78 NeuFlex implants broke. We found no major differences between the two designs, but the patients in the NeuFlex group seemed to be more satisfied with their occupational performance (COPM performance) (p=0.05).