The results in sixteen patients who had a displaced, comminuted intra-articular fracture of the distal end of the radius and who were treated by open reduction and internal fixation were retrospectively reviewed. At a mean follow-up of 4.8 years, 81 per cent of the patients had a rating of good or excellent by the scoring system of Gartland and Werley, but only 56 per cent had such a rating when the modified scoring system of Green and O'Brien was used. All of the fractures healed at an average of nine weeks. A step-off of two millimeters or more in the distal radial articular surface at the time of healing was important, because the four patients in whom the fracture healed with this amount of incongruity all had post-traumatic arthritis at follow-up, compared with only three of twelve in whom the incongruity was less than two millimeters.