Roberts D, Hng J, Rock P, et al. Anomalous insertion of the medial meniscus. Reference article, Radiopaedia.org (Accessed on 18 Apr 2024) https://doi.org/10.53347/rID-77558
Defined as a congenital variation in the insertion of the anterior root of the medial meniscus onto the anterior cruciate ligament (ACL). The anterior root most commonly inserts onto the intercondylar eminence of the tibia anterior to the ACL 1. Other meniscal variations include a discoid meniscus and transverse (meniscomeniscal) ligaments.
knowledge of the congenital variations of meniscal insertions and other variants will prevent misinterpretation
the ACL can have three bundles and has been seen in combination with an anomalous insertion of medial meniscus 3
bone marrow contusion patterns will aid interpretation in suspected ACL injuries, and the presence of a pivot shift pattern is associated with ACL tears 4
if available comparison with old or contralateral imaging will further aid in the interpretation
1.
Nguyen JC, De Smet AA , Graf BK, et al. MR Imaging–based Diagnosis and Classification of Meniscal Tears. (2014) RadioGraphics. 34 (4): 981-99. doi:10.1148/rg.344125202 - Pubmed
2. Cha JG, Min KD, Han JK, et al. Anomalous insertion of the medial meniscus into the anterior cruciate ligament: the MR appearance. (2008) The British journal of radiology. 81 (961): 20-4. doi:10.1259/bjr/66470309 - Pubmed
3. Getzmann JM, Bohnert L, Roos JE, et al. Anomalous insertion of the medial meniscus into a triple bundle anterior cruciate ligament: A rare combination of two anatomical variants. (2020) European journal of radiology open. 7: 100220. doi:10.1016/j.ejro.2020.100220 - Pubmed
4. Sanders TG, Medynski MA, Feller JF, et al. Bone Contusion Patterns of the Knee at MR Imaging: Footprint of the Mechanism of Injury1. (2000) RadioGraphics. 20 Spec No: S135-51. doi:10.1148/radiographics.20.suppl_1.g00oc19s135 - Pubmed