ostium bursa

例句：

1. 1. The joint was swollen and painful due to an infection in the ostium bursa.
   由于关节囊感染，这个关节肿胀并疼痛。
2. 2.The doctor performed a biopsy on the ostium bursa to determine the cause of the swelling.
   医生对关节囊进行了活组织检查，以确定肿胀的原因。
3. 3.Inflammation of the ostium bursa can lead to arthritis, which can be treated with medication.
   关节囊的炎症可能导致关节炎，可以通过药物治疗。