Isolated intra-articular fracture of the ulnar head.

Although injuries involving the distal radioulnar joint are common, articular fractures of the ulnar head without concomitant fractures of the radius are rare. This report details an isolated fracture of the ulnar head as it articulates with the sigmoid notch of the radius. This fracture pattern, not previously described in the literature, may be more common than presently appreciated. Herbert screw fixation was used with an excellent final outcome at 2-year follow-up.