Kirschner wire fixations for scapholunate dissociation: a cadaveric, biomechanical study.

PURPOSE To compare 5 different Kirschner wire fixation techniques in terms of the failure loads seen as scapholunate (SL) dissociation in a cadaveric, biomechanical study. METHODS 10 fresh-frozen, finger-amputated wrists with sectioned SL ligaments from 3 male and 2 female cadavers were tested. The change of SL angle, SL dissociation, and the load to failure of the 5 different Kirschner wire fixation techniques (using 1.4-mm Kirschner wires) were compared using an axial loading testing machine. The techniques were: (1) SL fixation (using one wire), (2) SL fixation (using 2 wires), (3) SL and scaphocapitate (SC) fixation, (4) SL, SC, and capitolunate (CL) fixation, and (5) CL fixation alone. RESULTS There was no significant difference between SL fixations using one or 2 wires. The force for SL dissociation was significantly greater in the SL-SC fixation than the SL fixation using one wire (p=0.003). The SL-SC-CL fixation was not significantly stronger than the SL-SC fixation. CONCLUSION The SL-SC fixation achieved adequate stabilisation of both carpal rows with minimal biological impairment.