-Caused Arthritis with Rice Body Formation: A Case Presentation and Literature Review.

A 68-year-old male patient came to the orthopedics department because of swelling and pain in his left shoulder joint. He received more than 15 intraarticular steroid injections in the shoulder joint at a local private hospital. MRI showed that the synovial membrane of the joint capsule was thickened and swollen, and there were extensive "rice body-like" low T2 signal shadows filling. Arthroscopic removal of rice bodies and subtotal bursectomy were performed. The observation channel was placed through the posterior approach, and a large amount of rice bodies in yellow bursa fluid were observed to flow out. Rice bodies with a diameter of approximately 1-5 mm filled the joint cavity were seen in the observation channel. The histopathological examination of the rice body showed that it was mainly composed of fibrin without a clear tissue structure. Bacterial and fungal cultures of synovial fluid suggested infection, so the patient received antifungal treatment. However, the shoulder swelled again after three weeks, MRI revealed that there was significant fluid accumulation in the subacromial-subdeltoid region with necrotic synovial tissue floating and ultrasound examination showed joint cavity effusion, synovial hyperplasia, and some synovium looked like "floating weeds". After 2 weeks, there were recurrent rice bodies in the articular cavity. Arthroscopic surgery was performed again to clean the joint and a catheter was placed for irrigation and drainage, and a large amount of necrotic synovial tissue floating as seen in ultrasound. Finally, patient received sensitive antifungal treatment and did not relapse within 6 months. During the recurrence in the current case, we recorded the process of rice body formation, which has for the first time been reported.