Septic Arthritis ICD-9
- 711.__(pyogenic arthritis)
Septic Arthritis Etiology / Epidemiology / Natural History
- Etiology: hematogenous, IV drug use, trauma, joint aspiration, contigous spread(cellulitis), osteomyelitis
- Risk Factors: diabetes, rheumatoid arthritis, lupus, HIV, steroid use, malignancy, IV drug use, elderly.
- Most common organism=S aureus > MRSA. Other causes: Neisseria gonorrhoeae, streptoccoci, E Coli, Pseudomonas, Clostridium. Fungal in HIV patients.
- Knee (50%), hip (20%), shoulder (10%), ankle (10%), Elbow(5%), Wrist (5%)
- Glycosaminoglycan degradtion begins within 5 days of infection, cartilage destruction by 7 days, Pannus overgowth @11days, joint capsule erosion @17days, fibrous ankylosis @5weeks.
Septic Arthritis Anatomy
Septic Arthritis Clinical Evaluation
- Warm, swollen, painful joint
- Limited ROM
- May have fever, chills
Septic Arthritis Xray / Diagnositc Tests
- Labs: ESR, CRP, blood cultures, CBC with differential
- Best diagnoses with joint aspiration with gram stain, examination for cyrstals, cell count, anaerobic culture, aerobic culture, acid-fast staining.
-WBC < 2,000mm3: non-inflammatory (SLE, systemic sclerosis, osteoarthritis, Gout.
-WBC <50,000mm3: infection unlikely
-WBC 50,000-100,000: concerning; may be seen with TB, gonococcal, immune compromise, partially treated infection, Gout, RA, Reiter's syndrome.
-WBC >100,000, 75% polymorphonuclear leukocytes: septic knee. (Schmerling RH, JAMA 1990;264:1009).
Septic Arthritis Classification / Treatment
- Thorough irrigation and debridement either by arthrotomy, or arthroscopy followed by antibiotics for 2-6 weeks determined by culture and sensitivities.
- Obtain 5 samples and culture for 2 weeks.
- Consider Naproxen / NSAID treatment to decrease cartilage loss.
- Septic Arthritis after knee ligament surgery.
Septic Arthritis Associated Injuries / Differential Diagnosis
Septic Arthritis Complications
Septic Arthritis Follow-up Care
- Consider referral to infectious disease for antibiotic management in complicated cases or those with drug resistant organisms.
- Follow responce to treatment with serial ESR and CRP. CRP returns to normal in 1 week, ESR in 3 weeks with adequate treatment.
Septic Arthritis Review References