SRS111 - Peroneal tendon anatomy in the retromalleolar region of the ankle: a new radiological classification

Abstract Background Lateral ankle pain can be caused by various pathologies, including those involving the peroneal tendons. The spatial arrangement of the peroneal tendons within the trimalleolar groove remains underexplored in the literature. Objective The objective of this study is to propose a new classification to describe and categorize the spatial relationship between the peroneal brevis and peroneus longus tendons at the level of the retro malleolar groove. Patients and Methods A retrospective analysis of the ankle joint anatomy on Magnetic Resonance Imaging (MRI) was conducted on 100 consecutive patients undergoing foot and ankle imaging . A musculoskeletal radiologist and orthopaedic surgeon meticulously evaluated the spatial relationship between the peroneus longus and peroneus brevis tendons in axial plane and subsequently categorized as follows:Type 1: PB tendon is deep to PL tendonType 2: PB tendon is less than 50% medial to PL tendonType 3: PB tendon is more than 50% medial to PL tendonType 4: PB tendon adjacent to PL tendon Descriptive statistics was performed of the cohort and intraclass correlation for interobserver reliability. Results In our study, the most common variant seen was type 1 (40% of cases) followed by type 2. There was good intraobserver reliability with intraclass correlation of 0.8. Conclusions Our study successfully introduces a novel classification system that effectively delineates and categorizes the spatial relationship between the peroneus brevis and peroneus longus tendons within the retromalleolar groove. This may be of clinical value during tendon repair and reconstruction.