Sonographic imaging of the patellofemoral medial joint stabilizing structures: findings in human cadavers

The medial soft-tissue restraints of the patella, specifically the medial patellofemoral ligament and the vastus medialis obliquus muscle, are critical to patellofemoral joint stability. A reliable and inexpensive imaging technique would be clinically useful especially after acute patellar dislocation. The medial patellofemoral ligament and the vastus medialis obliquus muscle were identified in cadaveric dissection. The attachments of the medial patellofemoral ligament to the patella and the adductor tubercle, and the attachments of the vastus medialis obliquus muscle to the adductor magnus tendon, adductor tubercle, and patella were carefully observed. Sonography then was performed on four thawed fresh frozen cadaver knees. After sonographic examination of these structures, the knees were dissected and the structures previously identified by sonography were verified. In all four specimens, these restraints of the patellofemoral joint were identified by sonography based on their imaging characteristics and surrounding bony and soft-tissue landmarks.