肘内側関節における稀な半月板の報告、肘の鳴きを引き起こし、関節鏡視下で治療

Lateral-sided elbow snapping is a rare clinical condition characterized by a painful, audible click during flexion and extension of the forearm over the lateral aspect of the elbow joint. It is typically attributed to intra-articular pathology such as inflammation or thickened synovial plicae, redundant or torn bundles of the annular ligament, and anatomical variations, such as the existence of a meniscus inside the joint cavity. We report a rare case in which the underlying cause was a brachioradial meniscus within the radiohumeral joint. Magnetic resonance imaging (MRI) suggested the presence of an interposed meniscus-like structure, which was confirmed during diagnostic arthroscopy. Arthroscopic ablation of the interposed tissue was performed, resulting in complete resolution of symptoms and restoration of full function. The brachioradial meniscus is an uncommon anatomical variant, with only a few cases previously documented. Although exceptionally rare, it should be considered in the differential diagnosis of painful lateral elbow snapping to avoid diagnostic oversight and inappropriate management. Early recognition and arthroscopic management can ensure excellent functional outcomes and prevent secondary chondral injury.