Thirty-three wrists in 25 patients with rheumatoid arthritis were followed for an average of 3.8 years after resection of the distal ulna. These patients, including those who had adjunctive implantation of a silicone rubber cap, manifested considerable amounts of carpal collapse, carpal translocation, rotational change of the wrist, and radial shift of the ulna. The progression of these complications was unpredictable. Four patients required revision. Three of these four patients had no articular contact between the lunate and radius on their preoperative x-ray film. Excision of less than 20 mm of the distal ulna is an acceptable range of resection. In 15% of the wrists, an osseous carpal stabilizer was seen on the preoperative x-ray film as a reliable radiographic indicator of radiocarpal stability. Another 12% of patients developed a bony carpal stabilizer during the postoperative period.