Are we managing acute knee effusion well?
Background: Non-traumatic knee effusion is a common referral to the on-call Orthopaedic team. The two most common causes of this presentation are septic and crystal arthritis. Crystal-induced arthritis can easily be overlooked or misdiagnosed as septic arthritis resulting in patients having unnecessary antibiotic therapy and surgical procedures. Objectives: To review our management of patients with hot swollen knees, especially those due to crystal arthritis. Materials and methods: We performed a retrospective study of patients presenting to the emergency department with acute non-traumatic knee effusion. A total of 180 patients were identified; 60 patients were included in the study. Results: All joints were aspirated and samples were sent for microscopy, culture and antibiotic sensitivity, and polarized light microscopy. Twenty six patients were admitted and received antibiotic therapy based on clinical suspicion of infection, arthroscopic washout was performed on eight. Four patients showed positive microscopic growth while eight had crystals identified on polarized light microscopy of joint aspirate. Only two (25%) patients with crystal arthropathy received appropriate treatment and a rheumatology referral. Seven patients developed complications during their hospital stay. Conclusion: Crystal arthritis is a common and serious cause of acute painful knee that can lead to joint damage if not treated properly. We should always remember to follow up the results of polarized light microscopy of joint aspirates. Prompt diagnosis can avoid unnecessary antibiotic therapy and surgical intervention. All patients with confirmed crystal arthritis should receive a rheumatology referral for further management and follow up. KEYWORDS: Crystal arthritis, gout, hot swollen knee, Pseudogout, polarized light microscopy.
