NONUNION OF THE SCAPHOID - TREATMENT WITH CANNULATED SCREWS COMPARED WITH TREATMENT WITH HERBERT SCREWS

We retrospectively reviewed the results for thirty-four patients in wh om a non-union of the scaphoid had been treated with bone-grafting and internal fixation with use of one of two types of screws as well as t he temporary placement of Kirschner wires parallel to the screw to pre vent rotation. The patients were divided into two groups: Group 1 cont ained sixteen patients who had been managed with a Herbert screw from 1986 through 1989 and Group 2, eighteen patients who had been managed with a 3.5-millimeter cannulated AO/ASIF screw from 1990 through 1992. There were no clinical or radiographic differences between the two gr oups. The time to union, confirmed with tomography, was 7.6 +/- 3.6 mo nths for Group 1 and 3.6 +/- 1.2 months for Group 2. This difference w as significant (p < 0.001). Both screws significantly improved the ali gnment of the scaphoid and decreased carpal collapse (p < 0.05). Regar dless of the type of Screw used, the time to union was significantly s horter when the screw had been placed in the central one-third of the scaphoid (p < 0.05). Seventeen of the eighteen cannulated screws had b een placed centrally, compared,vith seven of the sixteen Herbert screw s (p < 0.01).