Is the Articularis Genus an Independent Muscle? A Narrative Review of the Anatomical Definition and Continuity of the Articularis Genus with the Vastus Intermedius

ABSTRACT

The articularis genus (AG) is a small muscle located on the anterior aspect of the knee joint that has traditionally been described as retracting the suprapatellar bursa and joint capsule during knee extension. However, its anatomical definition remains controversial, particularly regarding whether it should be regarded as an independent muscle or as a structure continuous with the vastus intermedius (VI). This narrative review aimed to summarize the current anatomical evidence regarding the AG and to re‐examine its anatomical definition and potential clinical relevance. A literature search was conducted using PubMed and Scopus, and eight anatomical studies met the eligibility criteria. The origin and insertion of the AG were generally consistent among studies, with most describing its origin from the anterior distal femur and insertion into the suprapatellar bursa and/or joint capsule. In contrast, substantial discrepancies were identified regarding the number of muscle bundles, layered architecture, muscle length, and continuity with the VI. Some studies described the AG as an independent muscle, whereas others considered it continuous with the VI or both the VI and vastus medialis. These inconsistencies appear to result primarily from differences in the anatomical definition of the AG, particularly at its origin, where the fascial boundary with the VI remains unclear. Reconsideration of the anatomical concept of the AG may improve the interpretation of imaging findings, facilitate investigations of anterior knee pain, and provide a more consistent anatomical basis for surgical procedures, including total knee arthroplasty. Future studies integrating gross anatomy, histology, embryology, ultrasonography, and micro‐computed tomography are warranted to establish a standardized anatomical definition and clarify the functional and clinical significance of the AG.