The Impact of the Anteromedial Impingement Fracture of Tibial Plateau in Posterolateral Corner Injuries / 中国运动医学杂志

ABSTRACT

Objective To identify the incidence of the anteromedial impingement fracture of tibial plateau in the posterolateral corner injuries,and to confirm the relationship between the extent of the anteromedial tibial impingement fracture and the severity of the posterolateral instability of the knee joint.Methods The radiographic images of the posterolateral corner injuries were reviewed retrospectively to identify the incidence of the anteromedial impingement fracture of the tibial plateau.A matched group of the posterolateral corner injury patients without the anteromedial impingement fracture was compared with the anteromedial impingement fracture group for the posterior instability and varus instability.And the anteromedial impingement fracture group was subdivided into a marginal fracture group and a compression fracture group based on the size of the fracture,and the posterior instability and medial instability were compared between the two groups.Results From January 2007 to January 2017,there were 266 patients with posterolateral corner injuries admitted,with 19 (7.1％) combined with the anteromedial impingement fractures of the tibial plateau.The posterior instability was significantly severer in the fracture group than the control group (P=0.030),while there were no significant differences in the varus instability between them (P=0.800).Similarly,the posterior instability was significantly severer in the marginal group compared to the compression group (P=0.026),but without significant differences in the varus instability (P=0.397).However,the compression fracture group had a higher risk to have neurovascular injuries (of the popliteal artery and the common peroneal nerve) compared with the marginal fracture group.Conclusion The incidence of the anteromedial impingement fracture of the tibial plateau in posterolateral corner injuries was 7.1％.The anteromedial impingement fracture of the tibial plateau may indicate more severe posterior instability,and a compression fracture may suggest more severe posterior instability compared with the marginal fracture.If there is a compression type fracture,the neurovascular status must be carefully evaluated in addition to the examination of the posterolateral and posterior instability.