Unique stability of XXXX treated with the novel biplane double-supported screw fixation method: A biomechanical cadaver study.

@entity1 @entity71714 @entity2249 @entity174
UNASSIGNED: Osteosynthesis of @entity2249 is related to 20-46% complication rate. Filipov's novel method for biplane double-supported screw fixation ( @entity71714 ), using three cannulated screws, has demonstrated excellent clinical results since 2007. Its two calcar-buttressed screws are oriented in different coronal inclinations with steeper angles to the diaphyseal axis and intended to provide constant fixation strength under different loading situations. The aim of this study was to biomechanically evaluate @entity71714 fixation strength and compare it with the conventional fixation (CFIX) using three parallel cannulated screws. METHODS: Eight fresh-frozen and six embalmed @entity1 femoral pairs with simulated AO/OTA31-B2.2 @entity174 were fixed applying either CFIX or @entity71714 . Quasistatic tests were performed in anteroposterior (AP) bending, followed by axial quasistatic, cyclic and destructive quasistatic tests run in 10   flexion with 7   or 16   varus specimen inclination. RESULTS: Initial axial stiffness was significantly higher for @entity71714 in comparison with CFIX at 7   inclination (p=0.02) and not significantly different between @entity71714 and CFIX at 16   inclination. Compared with the intact state, it decreased significantly at 7   inclination only for CFIX (p=0.01), but not for @entity71714 . Interfragmentary displacement during cyclic testing was significantly smaller for @entity71714 than CFIX at 7   inclination (p <=0.04) and not significantly different between @entity71714 and CFIX at 16   inclination. Failure load did not differ significantly between @entity71714 and CFIX at both inclinations. CONCLUSIONS: @entity2249 stability can be substantially increased applying @entity71714 due to better cortical screw support and screw orientation. Having two calcar-buttressed screws oriented in different inclinations, @entity71714 can enhance constant stability during various @entity1 activities. The more unstable the situation, the better @entity71714 stability is in comparison to CFIX.
