Snapping knee caused by a popliteomeniscal fascicle tear of the lateral meniscus in a professional Taekwondo athlete.

A 19-year-old male professional Taekwondo athlete presented with a 2-year history of pain-free snapping of his right knee. He reported that his right knee joint gave way during games and training and that he could induce pain-free snapping between the proximal-to-fibular head and the lateral knee joint line. None of these physical findings suggested a meniscal pathology or ligamentous instability. Routine radiographs were normal. Magnetic resonance imaging of his right knee joint showed that the shape of the lateral meniscus was normal, and no lateral meniscus tears existed. On arthroscopic examination, popliteal hiatus view showed a posterosuperior popliteomeniscal fascicle tear between the posterior horn of the lateral meniscus and the posterior joint capsule just posteromedial to the popliteus tendon. With medial traction by probing, this popliteomeniscal tear made visible the significant subluxation of the posterior horn of the lateral meniscus to the center or anterior half of the tibial plateau. Based on the diagnosis of a posterosuperior popliteomeniscal tear of the right knee, Fast-Fix (Smith & Nephew, Andover, Massachusetts) was used for the direct repair of the peripheral portion of the lateral meniscus and joint capsule, targeting the popliteomeniscal junction. At 24 months postoperatively, the patient was performing athletic exercises relevant to his profession and was taking part in Taekwondo games, with no pain or recurrence of snapping. To the authors' knowledge, this is the first report of snapping of the lateral aspect of the knee due to a popliteomeniscal fascicle tear.