Septic arthritis or adult-onset Still's disease (AOSD) - Analyzing the causes of recurrent fever after arthroscopic combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction: a case report and literature review

Abstract

Abstract Background AOSD and septic arthritis share similar clinical symptoms, including recurrent fever, affected joint pain and limited mobility. This similarity poses diagnostic challenges when encountering a case of arthroscopic combined ACL and PCL reconstruction, where clinical evidence is insufficient to establish a definitive diagnosis between the two diseases. In this case, through a series of examinations and diagnostic treatment, the final diagnosis was AOSD. Case presentation A 41-year-old male who underwent arthroscopic combined ACL and PCL reconstruction half a month prior was admitted to our hospital with a weeklong history of recurrent fever and polyarticular pain. The positive physical signs and test results were insufficient to establish a definitive diagnosis between AOSD and septic arthritis. Therefore, a multidisciplinary team consisting of the orthopedic, infectious disease, rheumatism and immunology, hematology, respiratory, and pharmaceutical departments was formed to determine the diagnosis and establish a treatment plan. During the treatment period, the patient developed a typical rash and pharyngalgia. Multiple highly effective antibiotics were ineffective during the patient’s treatment, but the symptoms improved significantly after the administration of methylprednisolone, aspirin, and tocilizumab. The diagnosis of AOSD was ultimately determined according to the Yamaguchi criteria. After treatment, the patient's condition remained stable, and he was discharged from the hospital. During the subsequent two-month follow-up, the patient's condition remained stable without recurrence of symptoms, and the knee joint function returned to normal. Discussion and conclusion We could not retrieve any relevant case reports of AOSD after arthroscopic combined ACL and PCL reconstruction in several databases. Therefore, we believe this may be the first reported case. In conjunction with the relevant literature, we summarize the differences in clinical symptoms between septic arthritis and AOSD. Reviewing the patient's hospitalization process, we discuss the "controversial" diagnostic and therapeutic measures taken by the multidisciplinary team, along with any doubts and considerations. In conclusion, in cases where it is difficult to establish a definitive diagnosis between AOSD and septic arthritis, a collaborative approach involving multiple departments can be used for diagnosis and treatment, thereby shortening the diagnostic time and avoiding unnecessary diagnosis and treatment.