The goals with testing for septic arthritis are to identify the microorganism causing the infection, to determine which antimicrobial therapy will be effective, to monitor the effectiveness of treatment, and to evaluate the physical status of the affected joint(s).
- Blood culture – to determine if a microorganism is present in the blood
- Culture of joint fluid or of other body fluids or tissues, such as urine, sputum, cerebrospinal fluid – to detect microorganisms, to determine which antimicrobials they are likely to be susceptible to, and to evaluate the effectiveness of treatment
- Synovial fluid analysis – to detect microorganisms and to see if there are any signs, such as crystals in the joint fluid, that may indicate a different or co-existing cause for joint pain (such as gout)
- Complete Blood Count (CBC) – to evaluate red and white blood cells and hemoglobin to help evaluate and monitor the condition
- X-ray of joint(s) – to help evaluate joint damage; may not show abnormalities until significant damage exists