The correlation between posterior cruciate ligament buckling sign and meniscofemoral ligaments: A radiological study

Abstract

Objectives: This study aims to investigate the correlation betweenposterior cruciate ligament (PCL) buckling phenomena and thepresence or absence of the anterior meniscofemoral ligament(aMFL).Patients and methods: Between January 2012 and January2019, magnetic resonance imaging of a total of knee jointsof 199 patients (163 males, 16 females; mean age: 31.5±5.3years; range, 18 to 40 years) were reviewed retrospectively. Thepatients were divided into four groups. The first group included32 patients with a ruptured anterior cruciate ligament (ACL)and absent aMFL. The second group included 67 patients witha ruptured ACL and apparent aMFL. The third group included23 patients with an intact ACL and absent aMFL, and the fourthgroup included 77 patients with an intact ACL and apparentaMFL. The PCL angle was used to measure the buckling degreeof the ligament, as calculated as the angle between two linesdrawn through the tibial and femoral central portions of thePCL insertions. We assessed the buckling phenomena of thePCL in ACL-ruptured and ACL-intact knees and examined apossible correlation between the PCL buckling angle and thepresence or absence of the aMFL of Humphrey.Results: In the ruptured ACL groups (Groups 1 and 2),the mean PCL buckling angle values were 133.88±6.32 and104.83±7.34 degrees, respectively. A significant differencewas detected between both groups (p=0.026). In the intactACL groups (Groups 3 and 4), the mean PCL buckling anglevalues were 143.47±5.96 and 116.77±8.38 degrees, respectively.A significant difference was detected between both groups(p=0.039). No statistically significant difference was observedbetween Groups 1 and 3 (p=0.13) and between Groups 2 and 4(p=0.088).Conclusion: The PCL buckling sign is not specific for ACLruptures, and can be seen frequently in normal knee jointswhich it is strongly associated with the presence of aMFL ofHumphrey.