Anterior Attachments of the Medial Patellofemoral Ligament: Morphological Characteristics

The medial patellofemoral ligament (MPFL) is the most important passive restraint of the medial patella and provides approximately 53% to 80% of medial soft-tissue restraints, although its relationship to the parapatellar structures is still not completely understood.

Twenty-six formalin-fixed knees (13 for P45 plastination, 10 for dissection, and 3 for histology) were obtained from cadavers donated to the Department of Anatomy at Dalian Medical University. The mean age of the donors was 78.1 years (range, 52 to 95 years). These specimens were obtained from 4 women and 10 men. The integration of the anterior end of the MPFL with the extensor apparatus of the knee was observed, and the morphological observations were captured using a digital camera.

The MPFL was found to be attached to the extensor apparatus in 3 ways: its main fibers ran deep to the vastus medialis obliquus (VMO) tendon and ultimately inserted into it; its upper portion extended from, and was reinforced by, the vastus intermedius (VI) tendon; and its lower portion merged weakly into the parapatellar tendon. No direct attachment to the patella was found.

The MPFL attachments to the extensor apparatus occur in 3 locations: the VMO tendon, the VI tendon, and the parapatellar tendon-and not the patella. No direct attachment to that bone was identified. This study provides a comprehensive anatomical relationship between the MPFL and the extensor apparatus of the knee (the patella and quadriceps). Clinically, we suggest that reconstruction of the MPFL be performed with fixation of its anterior end to the VMO rather than to the patella.