患者 ,男 ,5 8岁 ,左膝关节包块酸痛年余 ,患者一年前发现左膝关节髌下有杏子大小肿块。随膝关节伸屈上下移动 ,伴轻微痛。当步行路程过多时 ,酸胀痛明显并逐渐增大。对伸屈膝关节无影响。查体 :左膝关节滑膜肥厚 ,髌下包块约鹅蛋大小质硬呈结节状 ,随膝关节伸屈在髌下上下移动 The patient, male, 5-8 years old, had a soreness in his left knee for more than a year. He had found a size of apricot in the left knee joint a year earlier. With knee joints flexing up and down, with minor pain. When walking too much, the soreness is noticeable and gradually increasing. No effect on knee flexion. Physical examination: Synovial hypertrophy of the left knee joint. The size of the infrapatellar mass is hard and nodular, and it moves up and down with the knee flexion.