Ligamentous injuries in Schatzker Ⅳ tibial plateau fracture: an MRI observation and their influence on knee instability / 中华创伤骨科杂志

ABSTRACT

Objective:To conduct an MRI observation on the incidences of ligamentous injuries and fracture morphology in Schatzker type Ⅳ tibial plateau fracture (TPF) and investigate their influence on knee stability.Methods:A retrospective analysis was conducted of the 30 patients with Schatzker type Ⅳ TPF who had undergone surgery at Department of Orthopaedic Trauma, Jiangsu Provincial People's Hospital from January 2010 to December 2019 and whose preoperative X-ray, CT and MRI were available. They were 18 males and 12 females, aged from 22 to 75 years (mean, 45.4 years). They were divided into a dislocation-free group and a dislocation group according to the absence or presence of knee dislocation on their anteroposterior X-ray films. The fracture morphology was assessed on CT according to the modified three-column classification. The incidences of ligamentous injuries [involving anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), posterolateral complex (PLC) and anterolateral ligament (ALL)] were investigated on MRI. The 2 groups were compared in fracture morphology and incidences of ligamentous injuries. Multiple linear regression (MLR) analysis was used to identify the main factor contributing to preoperative knee dislocation.Results:The dislocation group had 12 patients and the dislocation-free group 18. The fracture involving medial+posteromedial+posterolateral columns was found in 66.7% of the patients (20 cases), and accounted for 83.3% (10 cases) in the dislocation group. The incidence was 96.7% (29 cases) for ACL injury, 43.3% (13 cases) for PCL injury, 70.0% (21 cases) for MCL injury, 90% (27 cases) for PLC injury, 73.3% (22 cases) for ALL injury and 90% (27 cases) for the multiple-ligament disruption. There was a significant difference in the posterolateral column injury between the dislocation-free group [55.6% (10/18)] and the dislocation group [91.7% (11/12)] ( P < 0.05), but there were no significant differences between the 2 group in the injury to any other single ligament or multiple ligaments ( P>0.05). The MLR analysis confirmed that the posterolateral column injury was a risk factor for coronary plane dislocation in Schatzker type Ⅳ TPF( P<0.05). Conclusions:In Schatzker type Ⅳ TPF, the incidences of ligamentous injuries are very high but the fracture of posterolateral column may be the main cause for preoperative knee dislocation in some patients.