Distal radius fracture. Correlation between radiological and functional results

Background. The purpose of the present study was to investigate the influence of the radiological parameters on the functional outcome of patients with a fracture of the distal radius and to find out to which extent a deformity can be tolerated. Patients and methods. A total of 344 patients with an isolated fracture of the distal radius were treated during a 3-year period; 211 of them were evaluated at an average of 16 months after the accident according to the score of Gartland and Werley as modified by Sarmiento. Furthermore, we developed our own score for evaluating the influence of radiological parameters on the functional outcome. Results. According to the AO classification, there were 20 patients with an A2, 71 an A3, 11 a B, 35 a C1, 44 a C2, and 30 a C3 fracture. Of 211 patients, 28 (13%) had a step-off in the articular surface of over 1 mm, resuiting in a 24% reduction of the range of motion compared to the non-injured wrist (p < 0.05). Patients with a radial shortening of more than 3 mm (n=12) had a 21% reduction of pro- and supination compared to the noninjured side (p < 0.05). The radial tilt and the palmar inclination did not have a direct influence on the functional outcome. Patients treated with K-wire pinning and with an initial palmar inclination of less then -15 degrees had a significantly higher secondary loss of palmar inclination of 9 degrees compared to all others (p < 0.05) at the final follow-up. Conclusion. The main radiological factors influencing the functional outcome of fractures of the distal radius are radial shortening and a step-off in the articular surface.