Calcification of the Lateral Collateral Ligament as a Rare Cause of Knee Pain and Its Treatment With Ultrasound‐Guided Barbotage Procedure: A Case Report

Calcific periarthritis (CP) of the lateral collateral ligament (LCL) is a rare condition, and treatment protocols are unclear. A 48-year-old female patient presented with a 5-month history of localized pain in the lateral left knee. The clinical history, clinical findings, and imaging findings of the patient, in whom no abnormality was found in routine laboratory tests, were suggestive of CP. An ultrasound (US)-guided barbotage procedure was performed on the patient who did not respond to conservative treatment. This report aims to report the first case of successful treatment of CP of LCL with an US-guided barbotage procedure, which is a rare condition, and to discuss the available data in the literature.