Synopsis
Approach an acutely inflamed native joint as a time-dependent diagnostic and source-control problem, aspirate before antibiotics when physiology permits, interpret synovial findings safely, and coordinate drainage and targeted therapy.
- Any acutely hot, swollen and movement-limited native joint warrants septic-arthritis assessment; absence of fever or normal serum markers cannot safely exclude it.
- Aspirate synovial fluid as quickly as practical for cell count and differential, Gram stain, aerobic and anaerobic culture and crystals; inoculation into blood-culture bottles may improve yield under laboratory protocol.
- Take at least two sets of blood cultures in febrile or bacteraemic presentations and investigate the skin, urine, lungs, heart, injection sites and other joints for source and spread.
Key red flags
Hypotension, confusion, lactate elevation, rigors or rapidly progressive illness requires sepsis treatment and antibiotics after blood cultures without waiting for image-guided aspiration.
Investigation priorities
Obtain direct joint microbiology before antibiotics when safe.
Management branches
Organ dysfunction or high-risk sepsis accompanies a suspected infected native joint.
- Start ABCDE sepsis care and call orthopaedics, anaesthesia, microbiology and the relevant medical team.
- Take rapidly obtainable blood cultures, then give local empirical intravenous therapy without waiting for image-guided aspiration.
A native-joint effusion and movement pain are present without physiological instability.
Key medicines
Empirical intravenous native-joint therapyImmediately after synovial and indicated blood cultures in a stable adult, give the full dose and interval in the trust's native-joint septic-arthritis protocol; if sepsis is present, give it after rapidly obtainable blood cultures even when aspiration has not yet occurred.
Ceftriaxone for confirmed or strongly suspected disseminated gonococcal infectionUse ceftriaxone 1 g intramuscularly or intravenously every 24 hours under sexual-health and microbiology direction for disseminated gonococcal infection, then adapt duration and any oral step-down to cultures, susceptibilities and clinical response.