The correlation of the morphology of the medial patellofemoral ligament (MPFL) with the dimensions of the patella, the patellar tendon, the q-angle and femoral trochlear groove

[摘要] English: The medial patellofemoral ligament (MPFL) is an essential contributing component to a stable patellofemoral joint (PFJ). The PFJ is a complex structure that has balanced forces acting on the stable joint. The aim of this study was to correlate the morphology of the MPFL with the Q-angle, the patellar tendon, the patella and the femoral trochlear groove (FTG) in a stable PFJ. Thirty-four cadaver knees were dissected. The Q-angle for each knee was measured with a goniometer. Dimensions of the MPFL, patella and patellar tendon were measured with a Vernier calliper. The femoral trochlear groove was photographed and photometrically measured with the use of the computer program ImageJ. The data collected were statistically analysed to determine Spearman's Rank correlations coefficient (rs). A correlation coefficient of rs = 0.482 was considered significant. Firstly, it was found that the length of the MPFL correlated with eleven other measurements. These correlations include the proximal width of the patellar tendon; the length of the patellar tendon; the medial facet width of the patella; the articulating height of the patella; the osseous length of the patella; all the osseous measurements of the FTG; and the mathematically-derived depth of the FTG. Secondly, eight correlations were found with the femoral attachment width of the MPFL. These correlations include both the proximal and distal widths of the patellar tendon; the osseous length and width of the patella; the lateral patellar groove width of the FTG; both the medial and lateral altitudes of the FTG; and the altitude of the deepest point of the FTG. Lastly, the width of the attachment of the MPFL to the vastus intermedius tendon only correlated with the length of the patellar tendon. The morphology of the MPFL positively correlated with specific measurements of the patella, patellar tendon and the FTG in a stable PFJ. This may be explained by the gradual increase in size of the structures in the joint. The findings suggest that the MPFL forms part of a harmonious interplay and disrupting this balance, either by pathology or reconstructive surgery, may alter the delicate harmony in the joint.

[发布机构] University of the Free State