Approach Considerations
The most important consideration in the treatment of infectious arthritis is the rapid institution of appropriate antimicrobial therapy. Patients with bacterial arthritis must be hospitalized for parenteral antibacterial therapy and daily arthrocentesis. Daily joint aspiration must be performed until inflammation subsides. Mycobacterial and fungal infections are treated with appropriate agents. Perform surgical debridement if no response to medical therapy is observed.
Consultations that may be obtained include the following:
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Rheumatologist
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Orthopedic surgeon
Encourage either passive or active daily range-of-motion exercises. Avoid immobilizing the joint.
Pharmacologic Therapy
Intravenous (IV) antibiotic therapy is initiated immediately upon admission, as dictated by the results of a Gram stain and the clinical characteristics of the host. If the Gram stain result is positive for gram-positive cocci, then Staphylococcus aureus and streptococci are the most likely infecting agents. If the patient is a healthy, sexually active adult, gonococci and gram-positive cocci are the most likely infecting agents.
If the Gram stain result is negative in an elderly or compromised host, gram-negative rods are likely. Staphylococcus epidermidis and gram-negative rods are more likely in a patient with a prosthetic joint or a patient who has undergone a recent operative procedure.
Healthy adults can be treated with antistaphylococcal penicillin or cephalosporin. Patients who reside in communities with a high prevalence of community-acquired methicillin-resistant S aureus (MRSA) should be initially treated with vancomycin until culture results are available. [19]
Kingella kingae infections in pediatric patients are typically susceptible to aminoglycosides, macrolides, trimethoprim-sulfamethoxazole fluoroquinolones, and chloramphenicol. Many strains are clindamycin nonsusceptible, and all are highly resistant to vancomycin and other glycopeptide antibiotics. [8]
Elderly debilitated patients or patients with chronic medical conditions require expanded antimicrobial coverage to address gram-negative bacteria. This usually requires the addition of a third-generation cephalosporin, an aminoglycoside, or a quinolone.
Patients with nosocomial infections in whom pseudomonal species are considered may need an extended-spectrum penicillin, such as piperacillin or carbenicillin.
Cultural sensitivities, when available, may help identify appropriate modifications to subsequent therapy. Depending on the causative organism, most experts recommend 2-4 weeks of parenteral therapy.
Fungal arthritis is appropriately treated with IV amphotericin B plus an oral azole. The recommended duration of therapy is 6-12 weeks, for a total dose of 1-3 g of amphotericin B. [14]
Mycobacterial arthritis treatment varies, depending on the infecting agent. Patients with M tuberculosis infection are initially treated with 4 drugs (rifampin, isoniazid, pyrazinamide, and ethambutol [RIPE]) for 2 months; after this period, depending on the sensitivities, isoniazid and rifampin are continued for a total of 9-12 months. [14] Treatment of an M marinum infection requires administration of rifampin and ethambutol for 6-12 weeks.
Arthrocentesis, Arthroscopy, and Surgical Drainage
Daily arthrocentesis of the affected joint should be performed until synovial fluid culture results are negative or considerable clinical improvement in the joint is apparent. Joints that do not respond to antimicrobial therapy and daily arthrocentesis require drainage and debridement, either with arthroscopy or with an open procedure.
A joint with an infected prosthesis requires removal of the prosthesis and reimplantation after an appropriate course of antimicrobial therapy. The antibacterial prophylactic regimen indicated for patients with prosthetic joints undergoing surgical procedures is similar to that indicated for endocarditis prophylaxis in patients with valvular heart disease.
