Dong Hwan Lee

Rationale: The incidence of snapping popliteus tendon syndrome, a type of lateral knee snapping, is not high, so making an accurate diagnosis is difficult. A proper treatment following an accurate diagnosis is essential for improvement. Very few cases have been reported of its treatment. Patient concerns: An 18-year-old male patient had experienced painful popping in the lateral part of the knee during knee flexion for 3 years before his hospital visit. Diagnoses: Snapping popliteus tendon syndrome. Interventions: The patient underwent an all-arthroscopic surgery. Tendon debulking and tissue debridement around the popliteus tendon was conducted, but the snapping did not resolve. The enlarged tubercle was excised through an arthroscopic procedure using a burr, and the surgery was finished after confirming that snapping was resolved. Outcomes: Full range of motion (ROM) was recovered 6 weeks after surgery and the snapping did not recur. Lessons: Snapping popliteus tendon syndrome is a disease that is hardly recognized due to its low prevalence and difficulty in diagnosis, and it requires close observation of the patient before surgery. The location of the tenderness and the snapping occurrence must also be carefully identified. Our procedure is an entirely arthroscopic technique; as it has the prominent advantage of a speedy recovery and easy rehabilitation, it could also be helpful to set treatment standards for this disease in the future.