A Novel Ligamentous Complex in the Anteromedial Region of the Knee: A Cadaveric Study

Abstract

Background: The medial knee structures have a primary role in stabilizing valgus and rotational stress, which makes them important in assessing the ligament-injured knee globally and choosing the most adequate treatment. Purpose: To conduct a layer-by-layer dissection of the knee’s anteromedial side and provide a qualitative and quantitative description of the anatomy and histology of a ligament in the anteromedial region of the knee, which we have termed the anterior oblique ligament (AOL). Also, to describe the AOL relationship with what we have termed the medial cross—a ligament complex that stabilizes the medial pivot. Study Design: Descriptive laboratory study. Methods: A total of 35 fresh-frozen knees from transfemoral amputations that were exclusively performed for vascular reasons were dissected. Structures were identified after meticulous dissection, respecting the same protocol, measured with a digital caliper rule, and histologically studied for data. Results: The AOL was found in all dissected knees, with a mean length of 31.47 ± 5.06 mm. This structure presented a ligament histology with densely organized collagen fibrils. The medial cross was represented by the superficial medial collateral ligament, AOL (anterior region), and posterior oblique ligament. Conclusion: This study demonstrated the presence of a ligament in the anteromedial region of the knee, termed the AOL. This structure was in the anterior part of a ligament complex—the medial cross. Clinical Relevance: Studying and revisiting the medial compartment can provide important information for understanding joint instability and promoting better results in ligament reconstructions.