Displaced scaphoid fractures treated with open reduction and internal fixation with a cannulated screw

Background This study was performed to determine if the accuracy of screw p lacement was improved with use of the Herbert-Whipple cannulated screw comp ared with use of the AO/ASIF cannulated screw and also to evaluate the func tional results in patients with an acute displaced fracture of the waist of the scaphoid treated with open reduction and internal fixation with a cann ulated screw Methods: We retrospectively reviewed the results for thirty-five patients i n whom an acute displaced fracture of the waist of the scaphoid had been tr eated with internal fixation with use of a cannulated screw. The patients w ere divided into two groups; Group 1 consisted of nineteen patients managed with a 3.5-millimeter cannulated AO/ASIF screw from 1990 through 1997, and Group 2 consisted of sixteen patients managed with a Herbert-Whipple screw from 1993 through 1997, Results: There were no clinical or radiographic differences between the two groups. The average time to union land standard deviation), confirmed with tomography, was 4.2 +/- 1.2 months for Group 1 and 4.0 +/- 1.2 months for Group 2, Both screws significantly improved the alignment of the scaphoid a nd decreased carpal collapse (p < 0.01). Importantly, the use of either can nulated screw improved the height-to-length ratio and the lateral intrascap hoid angle, which were correlated with an increase in the range of motion o f the wrist (r = 0.584 and 0.625), In addition, both screws allowed for acc urate placement in the central portion of the proximal pole. Regardless of the type of screw used, the time to union increased with increasing age of the patient (r = 0.665) and with increasing initial displacement of the fra cture (r = 0.541), Within both groups, the time to union was longer for the patients who smoked (p < 0.01), Conclusions Within both groups, cannulated screw fixation maintained the co rrected fracture alignment and promoted healing and return of function. Our study shows cannulated screws to be a safe and effective method of treatme nt.