Clinical presentation and arthroscopic treatment of hypermobile Type III Wrisberg variant of lateral discoid meniscus: Report of nine cases

Background: The aim of the present study was to document a series of patients with meniscal hypermobility due to a Type III Wrisberg variant lateral discoid meniscus, describing their clinical presentation, analyzing their magnetic resonance imaging (MRI) and arthroscopic characteristics, and reporting the outcomes of an all-inside stabilization. Method: Nine cases of Wrisberg variant Type III discoid lateral menisci were identified based on patient's history and clinical examination. Knee MRIs were reviewed to exclude the presence of Type I–II discoid meniscus (complete or incomplete) or bucket handle tears and general arthroscopic criteria. For the Wrisberg variant discoid lateral meniscus were applied for the final diagnosis. Results: All nine cases presented similar peculiar clinical, radiological, and arthroscopic features, which led to the diagnosis of hypermobile Wrisberg variant of lateral discoid meniscus. This rareclinical entity is responsible for suggestive symptoms such as pain, popping and knee locking; moreover, subtle but peculiar MRI and arthroscopic characteristics can be observed. Conclusion: Considering the possibility of repeated dislocation and relocation, diagnosis can be challenging, and a high degree of suspicion should be used, especially in young patients, bilateral symptoms, and absence of trauma.