Search

Background: Discoid lateral meniscal (DLM) tears continue to pose significant clinical challenges, warranting further investigation into the patient profiles and imaging findings., Objective: To determine the MRI diagnostic performance in detecting isolated lateral meniscal tears (LMT) and discoid morphology, and to compare tear patterns and demographics between DLM and non-DLM tears., Materials and Methods: Retrospective study of patients undergoing arthroscopic surgery for isolated LMT between 2018 and 2023, comparing demographic data, mechanism of injury, imaging and operative findings between pediatric and young adult populations with isolated DLM and non-DLM tears., Results: Among the 312 knees (288 patients; mean age: 15.3 years; 22 % female), 123 knees (108 patients) exhibited DLM, while 189 knees (180 patients) were non-DLM. The DLM group had a lower mean age (13.9 vs. 16.1, P < 0.001) and a higher proportion of female patients (35 % vs. 14 %, P < 0.001). Patients under 12 were diagnosed with DLM in 96 % of cases. No known injury was reported in 30 % of DLM cases, significantly higher than in the non-DLM group (2 %, P < 0.001). Complex tears were most common in both groups (37 % vs. 39 %, P = 0.81). The sensitivity of MRI in detecting DLM was 73 %, with a specificity of 100 %. DLM was missed in 33 knees (27 %). Of these, 26 (79 %) had displaced LMT., Conclusion: DLM is common in operative isolated meniscus tears, with 96 % of patients under 12 years old diagnosed with DLM, and often presenting without a significant mechanism of injury. Pediatric radiologists should consider lowering their threshold to diagnose a discoid meniscus in cases of isolated displaced LMT, particularly in children under 12 years old., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)