MRI-Based Morphologic Patterns of the Peroneus Quartus in a Korean Clinical Cohort: An Anatomical Study with an Illustrative Surgical Case

Background/Objectives: The peroneus quartus (PQ) is an accessory musculotendinous structure of the lateral leg with variable origin and distal attachment. Although its anatomy has been described in cadaveric and imaging studies, the morphologic patterns encountered on routine ankle MRI remain clinically relevant. This study aimed to characterize MRI-visible PQ morphology in a Korean clinical cohort and to compare the observed patterns with previously reported anatomical variants. An illustrative surgically treated case was also reviewed.