Magnetic Resonance Imaging Features of Posterior Oblique Ligament Injuries

The purpose of this study was to improve the accuracy of the diagnosis of posteromedial knee joint injuries by describing the magnetic resonance imaging (MRI) features of posterior oblique ligament (POL) injuries. Fifty-five patients who presented with POL injuries observed on MRI from January 2016 to December 2017 were included. The MRI scans were retrospectively reviewed, and the image analysis protocol was confirmed by a fellowship-trained radiologist. Only one of the three portions of the POL was injured in 29 knees (seven knees, femoral origin; 18, midsubstance; and four, menisci insertion); multiple portions were injured in 26 knees (47.3%). The number of grade I, II, and III injuries was 7 (12.7%), 17 (30.9%), and 31 (56.4%), respectively. Forty patients (72.7%) had an accompanying superficial medial collateral ligament (sMCL) injury, and 31 (56.4%) had a meniscofemoral ligament injury. Thirty-three patients had documentation of the findings from examination under anaesthesia (EUA); all of them demonstrated laxity of the joint during valgus stress testing at 0 and 30 and had an accompanying sMCL injury. The types of POL injuries by dividing the POL into three portions in the study, furthermore, the combined injuries of the medial menisci, cruciate ligaments, and medial knee ligaments were summarised. Comprehensive and accurate assessment of POL injuries and associated injuries can help orthopaedic doctors accurately assess knee injuries and select the appropriate treatment plan.