What is the treatment for septic arthritis?

Treatment of Septic Arthritis

The treatment of septic arthritis requires immediate surgical debridement combined with appropriate antibiotic therapy, typically lasting 3-4 weeks for uncomplicated cases. 1

Diagnostic Confirmation

• Septic arthritis is an orthopedic emergency as bacterial proliferation can rapidly cause cartilage damage 1
• Joint aspiration is the definitive diagnostic procedure with synovial fluid white blood cell count ≥50,000 cells/mm³ suggestive of septic arthritis 1
• Synovial fluid culture is positive in approximately 80% of non-gonococcal septic arthritis cases 1

Treatment Algorithm

Surgical Management

• Arthrotomy, irrigation, and debridement are the standard surgical interventions for septic arthritis 2
• Surgical debridement with intraoperative cultures is the preferred approach for surgical emergencies 1
• Arthroscopic drainage may be used as an alternative to open arthrotomy in appropriate cases 3

Antibiotic Therapy

• Empiric antibiotic therapy should be initiated immediately after synovial fluid has been obtained 4
• IV vancomycin is recommended as first-line therapy for adults with septic arthritis 1
• For children, appropriate antibiotics include:
  • Amoxicillin, cefuroxime axetil, or doxycycline (if ≥8 years of age) 2
  • IV vancomycin for MRSA coverage, with clindamycin as an alternative if resistance is low 1
• Oral antibiotics can be given in most cases as they are not inferior to intravenous therapy 4, 5
• After 2-4 days of intravenous therapy, treatment can be safely switched to oral antibiotics if using large doses of well-absorbing antibiotics 5

Duration of Treatment

• Total duration of therapy typically ranges from 2-6 weeks 4
• A 10-day course may suffice for previously healthy children in a Western setting 5
• For prosthetic joint infections, longer antibiotic courses (12 weeks) show better outcomes than shorter courses 1

Pathogen Considerations

• Staphylococcus aureus is the most common pathogen isolated in septic arthritis 4
• In children <4 years, Kingella kingae should be considered 1, 6
• In neonates, Group B streptococcus is a common pathogen 6
• In patients with sickle cell disease, Salmonella species should be considered 1, 6
• For polymicrobial infections, dual antibiotic coverage is necessary 1

Special Considerations

• Adding rifampin to the regimen may be beneficial due to its excellent penetration into bone and biofilm 1
• Concomitant osteomyelitis occurs in up to 30% of children with septic arthritis and requires longer treatment 1
• For persistent or recurrent joint swelling after a course of oral antibiotics, re-treatment with another 4-week course of oral antibiotics or 2-4 weeks of IV ceftriaxone is recommended 2
• If arthritis persists despite IV therapy, and synovial fluid PCR is negative, symptomatic treatment with NSAIDs or DMARDs may be considered 2
• Arthroscopic synovectomy may reduce the duration of joint inflammation in cases of persistent synovitis with significant pain or functional limitation 2

Pitfalls and Caveats

• Negative joint aspirate culture does not rule out infection; consider percutaneous bone biopsy if clinical suspicion remains high 1
• Delay in diagnosis and treatment can result in permanent morbidity and mortality 4
• Medical treatment (arthrocentesis) may be as effective as surgical treatment for native joint septic arthritis with shorter hospital stay (21 vs. 33 days) and better functional outcomes in select cases 3
• Age is an independent risk factor for treatment failure 3
• Intra-articular injections of corticosteroids are not recommended during active infection 2