Atypically Displaced Meniscal Tears: An Educational Review with Focus on MRI and Arthroscopy

This review article on atypically displaced meniscal tears serves as a critical reminder for radiologists and orthopedic surgeons. It highlights and details uncommon lesions that may be overlooked during MRI evaluation and/or arthroscopic exploration. The knowledge of their existence can enable radiologists to critically assess any meniscal abnormality, keeping in mind its possible arthroscopic presentation. This is essential for assisting the surgeon in making an accurate preoperative diagnosis. In fact, these atypical lesions pose great challenges to surgeons in terms of the technical aspects of their treatment. Often, they could require additional arthroscopic portals for their identification or the need for special devices or instrumentations for the repair. Knowing these challenges in advance is thus imperative for properly planning a proficient surgery. The correct diagnosis and description of tear patterns, including extent and location, allow optimal pre-operative planning with the choice of the indicated approach. Radiologists should know how to recognize menisci tears, even with atypical dislocation patterns. Particularly, in the case of 'minus' detection or thickness reduction in a meniscus, the possible displaced fragment should be carefully searched for, even in atypical sites.