Knee Locking and Diagnosis Unlocking: Understanding and Treating the Hypermobile Lateral Meniscus.

Context: Hypermobility of the lateral meniscus is a relatively uncommon condition characterized by excessive, abnormal movement of the lateral meniscus in the knee joint. This literature review and case report aims to provide insights into the clinical presentation, diagnosis, and treatment options for peripheral lateral meniscocapsular tears that result in excessive lateral meniscal motion.

Evidence acquisition: A narrative review of the literature and the clinical expertise of the authors.

Study design: Narrative overview.

Level of evidence: Level 5.

Results: A hypermobile lateral meniscus poses diagnostic challenges due to overlapping symptoms with other knee pathologies. The anatomy of the posterolateral meniscocapsular recess and popliteus hiatus can distort the ability to accurately diagnose tears of the peripheral attachments of the posterior horn of the lateral meniscus. In a primary care practice, recognition of this condition in patients presenting with recurrent mechanical catching or locking episodes, sometimes with a "normal" magnetic resonance imaging (MRI) scan, is crucial to refer to orthopaedics in a timely manner to prevent further damage. Arthroscopic meniscal repair can be an effective treatment option, facilitating a safe return to sports after rehabilitation.

Conclusion: A hypermobile lateral meniscus and peripheral meniscocapsular tears of the lateral meniscus should be considered in the differential diagnosis of knee pain with recurrent locking episodes, even with an "unremarkable" MRI scan. Timely and accurate diagnosis and appropriate intervention, such as arthroscopic meniscal repair, can lead to better quality of life. Further research is needed to explore long-term outcomes and optimal management strategies for hypermobile lateral meniscal tears.Strength-of-Recommendation Taxonomy (SORT):Level C.