患者男,18岁。1年前从高处落地后出现右膝关节肿痛、活动受限,经石膏固定后仍反复发作性疼痛,大量活动后加重。病程中无发热史,否认肝炎及肺结核史。体检:右膝关节肿胀,无红热,其内外侧及髌上、髌下区广泛压痛;腘窝可及2枚结节样肿块;屈伸活动受限,Shelf征(+)。实验室检查:血沉 Patient male, 18 years old. A year ago, after falling from a height, he developed right knee swelling and pain. His activity was limited. He was still suffering from episodic pain after being gypsum fixed and exacerbated after a large number of activities. No history of fever in the course of history, to deny the history of hepatitis and tuberculosis. Physical examination: Right knee joint swelling, no red hot, the medial and lateral patellar, suprapatellar area with extensive tenderness; popliteal fossa and 2 nodular lumps; limited flexion and extension activities, Shelf sign (+). Laboratory tests: ESR