A systematic review of pes anserinus variations, their anatomical types, prevalence, and clinical reflections.

purposeThe pes anserinus (PA) is formed by the sartorius, gracilis, and semitendinosus tendons, serving as a common graft source in knee surgery. However, variations in tendon convergence, accessory slips, and insertion sites may directly affect surgical outcomes. This systematic review aimed to analyze the morphological variations of the PA, their prevalence, and clinical implications.

methodsFollowing PRISMA 2020 guidelines, a systematic search was performed in PubMed, Scopus, Web of Science, and Google Scholar using the terms “pes anserinus,” “anatomy,” “morphology,” and “variation.” Eligible studies included human cadaveric or imaging-based investigations published in English after 2000. Study quality was assessed using the AXIS tool.

resultsFourteen studies comprising 769 knees were included. The pooled prevalence of the classical tri-tendinous configuration was 62%. Variations were most frequently observed in the semitendinosus tendon, while gracilis showed inconsistent rates across populations, and sartorius variations were rare. Accessory bands were reported in up to 100% of some series. These findings are clinically significant, as unrecognized variants may lead to graft insufficiency, stripper slippage, or diagnostic errors in imaging.

conclusionThe PA exhibits wide interindividual variability beyond the classical configuration. Awareness of these variations is essential for surgeons and radiologists to prevent complications. Larger studies incorporating biomechanical analyses are needed to better clarify the clinical importance of PA variations.