Biomechanical analysis on three internal fixations for posterolateral 1/2 tibial plateau fracture

LIU Shi-jun; LI Zhi-guo; MA Zhi-guo; FENG Zhi-wei; SUO Hai-jun; LOU Hong-liang

doi:10.3969/j.issn.1009-4237.2017.05.005

Abstract：Objective To analyze three internal fixations for posterolateral 1/2 tibial plateau fracture through biomechanical and finite element analysis methods. Methods Twenty-four fresh adult cadaver tibia specimens were selected and made into posterolateral 1/2 tibial plateau fracture models by electric saw.They were divided into anterior screw fixation group (8 cases),lateral L type plate fixation group (8 cases) and posterior T type plate fixation group (8 cases).A healthy male volunteer was selected,who was given CT on knee joint and the data was imported into Mimics 14.0 software to make tibial plateau and fracture model.Axial load was given on solid specimen and finite element model.The displacement and stress of fracture mass were compared among groups. Results There was no significant difference in displaced fragment of bone on 250N,500N and 1000N axial load among 3 internal fixations models[250N:(0.14±0.02)mm vs.(0.13±0.02)mm vs.(0.14±0.13)mm;500N:(0.27±0.05)mm vs.(0.29±0.06)mm vs.(0.28±0.07)mm;1000N:(0.49±0.12)mm vs.(0.53±0.10)mm vs.(0.50±0.09)mm;P>0.05].The bone displaced distance of fragment of anterior screw fixation group (0.57±0.14)mm was lower than that of other groups[(0.72±0.10)mm,(0.76±0.13)mm] on 1500N axial load(P<0.05).In finite element,the bone displaced distance of fragments of anterior screw fixation were less than those of other two groups on all axial loads (P<0.05);the maximum displacement distribution regions were all located into proximal tibial joint junction. Conclusion For posterolateral 1/2 tibial plateau fracture,all three fixation methods can provide early stability,while the stability of anterior screw fixation is better than lateral L type plate fixation and posterior T type plate fixation.