Anatomical and radiographic characterization of the lateral patellofemoral ligament of the knee

Abstract

The purpose of this investigation was to isolate and characterize the patellar and femoral insertions of the Lateral Patellofemoral Ligament (LPFL) and define the corresponding radiographic landmarks. Ten embalmed cadaveric knees were dissected in order to examine the lateral patellofemoral structures. The LPFL was isolated and the surrounding soft tissue was removed. Measurements of the ligament were obtained with digital calipers. The patellar and femoral insertions of the ligament were identified and characterized based on their positions relative to known anatomic landmarks. Each specimen was examined radiographically after a radiopaque marker was placed at the center of the femoral insertion of each of the ligaments. The average center of the femoral insertion of the LPFL was calculated in reference to radiographic landmarks, including the Blumensaat's line and the posterior surface of the femoral cortex. The patellar insertion of the LPFL was found to consistently encompass the entire lateral margin of the patella. The data was analyzed using regression analysis. This allowed us to formulate an equation to determine the center of the femoral attachment of the LPFL based on measurements taken from a lateral and AP radiographs of each femur. Research support was provided by the Department of Anatomy at A.T. Still University.