Medial patellofemoral ligament: Cadaveric investigation of anatomy with MRI, MR arthrography, and histologic correlation

OBJECTIVE. The purpose of this study was to use MRI with gross anatomic and histologic correlation in cadavers to define the anatomic details of the medial patellofemoral ligament. MATERIALS AND METHODS. MRI of seven cadaveric knees was performed before and after intraarticular administration of a gadolinium solution. T1-weighted spin-echo MR images with and without fat suppression were acquired in three planes. Correlation was made between findings derived from MRI and cadaveric sections. Histologic analysis was performed on five specimens. RESULTS. The bilaminar and trilaminar appearance of the medial patellar ligamentous complex was defined on axial images. The medial patellofemoral ligament and the medial patellotibial ligament were best visualized on axial images. In three of five knees, the superficial fibers of the medial patellofemoral ligament were attached to the epicondyle in a position posterior to the attachment point of the tibial collateral ligament. In all three knees, the deep fibers of the medial patellofemoral ligament merged with and attached to the tibial collateral ligament. In two of these five knees, all fibers of the medial patellofemoral ligament were attached to the tibial collateral ligament. These findings were confirmed at histologic examination. CONCLUSION. The medial patellofemoral ligament can attach only to the tibial collateral ligament or to both the tibial collateral ligament and the femoral epicondyle. The bilaminar and trilaminar appearances of the medial patellar ligamentous complex and the course of the medial patellofemoral, medial patellomeniscal, and medial patellotibial ligaments were best defined on axial images.