Anatomical Study of the Innervation of Anterior Knee Joint Capsule: Implication for Image-Guided Intervention.

BACKGROUND AND OBJECTIVES: The knee joint is the most common site of osteoarthritis. While joint replacement is considered an ultimate solution, radiofrequency denervation may be contemplated in some cases. Radiofrequency ablation requires precise localization of the articular branches innervating the joint capsule. The objective of this cadaveric study was to determine the source, course, relationships, and frequency of articular branches innervating the anterior knee joint capsule.

METHODS: Fifteen knees were meticulously dissected. The number and origin of the articular branches were recorded, and their distribution defined by quadrants. Their relationships to anatomical landmarks were identified.

RESULTS: The articular branches terminated in 1 of the 4 quadrants with minimal overlap. In all specimens, the superolateral quadrant was innervated by the nerve to vastus lateralis, nerve to vastus intermedius, superior lateral genicular and common fibular nerves; inferolateral by the inferior lateral genicular and recurrent fibular nerves; superomedial by the nerve to vastus medialis, nerve to vastus intermedius and superior medial genicular nerve; and inferomedial by the inferior medial genicular nerve. In 3 specimens, the inferomedial quadrant also received innervation from the infrapatellar branch of saphenous nerve. All articular branches except the nerves to vastus lateralis and medialis course at the periosteal level.

CONCLUSIONS: The frequency map of the articular branches provides an anatomical basis for the development of new clinical protocols for knee radiofrequency denervation and perioperative pain management.