Biomechanical analysis of "Barrel hoop plate" technique for the posterolateral fragments of tibial plateau fractures with different displacement tendency

Objectives: The purpose of our study is to evaluate the three-dimensional biomechanical properties of "Barrel Hoop plate" in two kinds of artificial posterolateral tibial plateau fracture fragment (PLF) by using of synthetic models, each of which has an initial amplifying displacement tendency.

Material and methods: Thirty-six tibiae models were randomly assigned into two groups with different displacement tendencies: posterior displacement (PD) and lateral displacement (LD). Each model was then fixed with three patterns: Anterolateral plate (AP), Posterolateral plate (PP), and "Barrel Hoop plate" (BHP). Displacement in three axes of vertical, sagittal and horizontal axis was captured by Optotrak Certus motion analysis system. Bluehill 2 software was used for load control and data collection.

Results: In Model-PD, when the load was over 1000 N, the posterior displacement of Group-PP and Group-BHP were less than Group-AP (P<0.01). The inferior displacement in the vertical axis of Group-PP was larger than both Group-AP and Group-BHP in all the loading set (P<0.01). In Model-LD, both of the lateral displacement in Group-AP and Group-BHP was less than that of Group-PP when the load was over 1000 N (P<0.01). The inferior displacement of Group-AP was less than that of Group-PP in the load of 1500 N (P<0.01). Both of the posterior displacement of Group-AP and Group-BHP was less than that of Group-PP when the loading was 1500 N (P<0.01). The stiffness of Group PP was less than that of Group AP (P<0.01).

Conclusions: The results demonstrated that the 2.7 mm "Barrel Hoop plate" had a greater capacity of anti-three-dimension axes displacement of PLF. The 3.5 mm Anterolateral plate had the advantage in anti-lateral displacement and anti-inferior displacement but was weak at anti-posterior displacement of PLF. The 2.7 mm Posterolateral plate was stronger in anti-posterior, however, weak in anti-inferior displacement capacity.