Guideline sources The following summarized guidelines for the evaluation and management of septic arthritis are prepared by our editorial team based on guidelines from the European Bone and Joint Infection Society (EBJIS 2023), the American College of Radiology (ACR 2022), and the Infectious Diseases Society of America (IDSA 2016; 2011). 1 2 3 4 5 Calculator Kocher criteria for septic arthritis Guidelines 1. Screening and diagnosis https://web.pathway.md/diseases/recoJ2OZwj4SwtBdp 1/5 6/24/23, 3:10 PM Septic arthritis Pathway Diagnosis: suspect septic arthritis of a native joint in patients with a painful and/or inflamed joint (redness, hot, swelling, synovial effusion, and/or purulent drainage) with or without a fever. Do not exclude or confirm septic arthritis of a native joint based on no clinical parameters. B 2. Diagnostic investigations History and physical examination: Elicit a thorough medical history and perform a physical examination in patients with suspected septic arthritis in a native joint. B Obtain clinical assessment to identify concomitant sepsis or septic shock requiring immediate attention and rapid surgical and medical treatment. B Laboratory tests: insufficient evidence to recommend a blood test to confirm or exclude septic arthritis of a native joint. Show 2 more Diagnostic imaging: As per EBJIS 2023 guidelines, consider obtaining plain joint radiographs to screen for preexisting conditions (fracture, osteomyelitis, OA, implants). Consider using radiographs as a reference for future monitoring. C Show 2 more As per ACR 2022 guidelines, obtain radiography as initial imaging for suspected septic arthritis. B Show 2 more 3. Diagnostic procedures Synovial fluid analysis (aspiration): perform aspiration of synovial fluid as quickly as possible when septic arthritis of a native joint is suspected. B Show 5 more Synovial fluid analysis (differential cell count and microscopy): obtain synovial fluid analysis for bacterial identification, WBC count including polymorphonuclear percentage, and presence of crystals. B Consider obtaining additional investigation such as analysis of synovial lactate and synovial glucose. B Show 5 more Synovial fluid analysis (culture): obtain synovial fluid for microbiological culture. Send synovial fluid of 1 mL for culture in sterile tubes. B Inoculate the remaining synovial fluid into blood culture bottles if fluid is left over after initial sampling for culture, WBC count, and crystal analysis. B Show 5 more https://web.pathway.md/diseases/recoJ2OZwj4SwtBdp 2/5 6/24/23, 3:10 PM Septic arthritis Pathway 4. Medical management Antibiotic therapy: consider initiating antibiotic treatment in patients with suspected septic arthritis of a native joint after aspiration of synovial fluid for laboratory analysis and obtaining blood cultures. B Show 5 more 5. Nonpharmacologic interventions Early mobilization: consider starting mobilization as soon as possible once the infection is under control and after drains have been removed and surgical wounds closed. C 6. Surgical interventions Indications for surgery: Offer invasive treatment (open surgery, arthroscopy, or arthrocentesis) to wash out toxins and reduce both the bacterial load and intra-articular pressure: perform surgical debridement for septic arthritis of a native joint, especially in larger joints consider performing arthroscopic debridement as initial surgical management in patients with G chter stage I, II, and probably also III septic arthritis (if logistically and surgically possible) consider performing open debridement in patients with G chter stage III and definitely in stage IV. B Show 2 more 7. Specific circumstances Pediatric patients: obtain culture of synovial fluid collected by joint aspiration. B Show 8 more Patients with septic arthritis after ACL reconstruction: suspect septic arthritis after reconstruction of the ACL in the presence of a delayed ROM recovery, increased warmth or swelling, wound drainage and arthrofibrosis, unusual pain, and systemic symptoms, such as fever and malaise. Confirm the diagnosis in the presence of purulent discharge/aspirate, sinus tract communication with the joint, and intra-articular pus. B Show 4 more Patients with MRSA septic arthritis: perform drainage or debridement of the joint space in patients with MRSA septic arthritis. B Show 3 more Patients with tuberculosis arthritis (evaluation): Suspect tuberculosis arthritis in patients with a subacute or chronic course of arthritis (weeks to months or even years), especially in patients living in or previously living in endemic areas or with a prior history of tuberculosis. B https://web.pathway.md/diseases/recoJ2OZwj4SwtBdp 3/5 6/24/23, 3:10 PM Septic arthritis Pathway Perform synovial biopsies for microbiological cultures and histopathological analysis in case of surgical intervention and/or suspicion of tuberculosis. B Analyze the synovial fluid and synovial biopsies for AFB stain, mycobacterial culture, and NAAT. B Patients with tuberculosis arthritis (management): initiate medical therapy alone for the treatment of early cases of tuberculosis arthritis. B Show 6 more Patients with Candida septic arthritis: initiate fluconazole 400 mg (6 mg/kg) daily for 6 weeks or an echinocandin (caspofungin 50-70 mg/day, micafungin 100 mg/day, or anidulafungin 100 mg/day) for 2 weeks, followed by fluconazole 400 mg (6 mg/kg) daily for at least 4 weeks in patients with Candida septic arthritis. B Show 4 more Patients with Aspergillus septic arthritis: perform surgical intervention, if possible, and administer voriconazole for the management of patients with Aspergillus arthritis. B 8. Follow-up and surveillance Assessment of treatment response: Assess for the following signs and laboratory markers as indicators of treatment failure: Situation Guidance Persistent pain, local signs of inflammation (including the presence of purulent discharge), systemic signs of infection, and/or deteriorating joint function Clinical signs and symptoms CRP and WBC count not decreasing or instead increasing Inflammatory biomarkers Elevated or not decreasing WBC count and percentage polymorphonuclear leucocytes, persistently positive microbial cultures. B Synovial fluid at re-aspiration in case of poor clinical progression Show 2 more Likelihood Ratios Pertinent positives The following findings increase the probability of septic arthritis in adults. 1 5 Finding LR+ Value Increased synovial fluid WBC count 7.8 Presence of recent joint surgery 6 https://web.pathway.md/diseases/recoJ2OZwj4SwtBdp 4/5 6/24/23, 3:10 PM Septic arthritis Pathway Presence of age > 80 Increased synovial fluid polymorphonuclear cells 3.8 3.5 Show 13 more Pertinent negatives The following findings decrease the probability of septic arthritis in adults. 1 5 Finding LR- Value synovial fluid LDH not increased 0 serum LDH not decreased 0.1 ESR not increased 0.2 WBC count not increased 0.3 Show 13 more References 1. Christen Ravn, Jeroen Neyt, Natividad Benito et al. Guideline for management of septic arthritis in native joints SANJO . J Bone Jt Infect. 2023 Jan 12;8 1 29 37. Open 2. Patterson TF, Thompson GR rd, Denning DW et al. Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America. Clin Infect Dis. 2016 Aug 15;63 4):e1-e60. Open 3. Pappas PG, Kauffman CA, Andes DR et al. Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America. Clin Infect Dis. 2016 Feb 15;62 4):e1 50. Open 4. Catherine Liu, Arnold Bayer, Sara E Cosgrove et al. Clinical Practice Guidelines by the Infectious Diseases Society of America for the Treatment of Methicillin-Resistant Staphylococcus aureus Infections in Adults and Children. Clin Infect Dis. 2011 Feb 1;52 3):e18 55. Open 5. Expert Panel on Musculoskeletal Imaging, Jennifer L Pierce, Michael T Perry et al. ACR Appropriateness Criteria Suspected Osteomyelitis, Septic Arthritis, or Soft Tissue Infection Excluding Spine and Diabetic Foot): 2022 Update. J Am Coll Radiol. 2022 Nov;19 11S S473 S487. Open 6. Mary E. Margaretten, MD, Jeffrey Kohlwes et al. Does This Adult Patient Have Septic Arthritis?. JAMA. 2007;297 13 1478 1488. Open 7. Expert Panel on Musculoskeletal Imaging:, Francesca D Beaman, Paul F von Herrmann et al. ACR Appropriateness Criteria Suspected Osteomyelitis, Septic Arthritis, or Soft Tissue Infection Excluding Spine and Diabetic Foot). J Am Coll Radiol. 2017 May;14 5S S326 S337. Open https://web.pathway.md/diseases/recoJ2OZwj4SwtBdp 5/5