Volar Barton's fractures with concomitant dorsal fracture in older patients

PURPOSE: To describe a variant of Barton's volar articular shearing fracture of the distal radial articular surface with a subtle concomitant fracture of the dorsal metaphyseal cortex. METHODS: This fracture pattern was observed in 6 women and 2 men with an average age of 67 years (range, 58-76 years). All 8 patients were treated with a volar plate and screws. The dorsal metaphyseal fracture was not recognized in 5 patients and a volar buttress plating technique using an intentionally undercontoured volar plate was used. In 3 patients the dorsal fracture line was identified before surgery and the plate was contoured to fit the volar surface of the distal radius. RESULTS: All 5 patients treated with an undercontoured plate had loss of the normal palmar tilt of the distal radius (average,-9.4 degrees; range, 0 degrees to-22 degrees ) and dorsal translation of the distal radial articular fragments. For the entire group the palmar tilt averaged-5.9 degrees (range, 0.0 degrees to-22.0 degrees ), the ulnar inclination 19 degrees (range, 10 degrees -23 degrees ), and the ulnar variance-0.9 mm (range, 0.0 to-3.0 mm). All patients attained forearm supination of 80 degrees and the average pronation was 75 degrees (range, 45 degrees -80 degrees ). According to Sarmiento's modification of the system of Gartland and Werley there were 1 excellent, 6 good, and 1 fair results. The average Patient-Rated Wrist Evaluation score was 16 (range, 0-35). CONCLUSIONS: Some fractures with an oblique volar marginal articular fracture of the distal radius and volar radiocarpal subluxation (known as Barton's fracture) may also have a fracture through the dorsal metaphyseal cortex. Failure to identify this fracture line can lead to dorsal translation and angulation of the distal radius articular surface, particularly when an undercontoured volar plate is used for internal fixation.