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Periprosthetic Joint Infection

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Periprosthetic Joint Infection, Prosthetic Septic Joint, Prosthetic Joint Infection, Infected Joint Replacement

  • See Also
  1. Septic Joint
  2. Septic Joint Causes
  • Risk Factors
  1. Obesity (highest risk)
  2. Cardiac disease
  3. Immunocompromised
  4. Peripheral Vascular Disease
  5. Inflammatory Arthritis
  6. Prior joint infection
  7. Renal disease
  8. Liver disease
  9. Malnutrition
  10. Alcohol Abuse
  11. Tobacco Abuse
  12. Diabetes Mellitus
  13. Anemia
  14. Advanced age (esp. age >80 years old)
  15. Tubb (2020) J Am Acad Orthop Surg 28(8): e340-8 [PubMed]
  • Epidemiology
  1. Prosthetic Joint Infection carries a 1-2% risk at 2 years and >2% at 10 years
  2. Nearly half of infections occur in the first 3 months after surgery (nearly 80% occur within first 2 years)
  3. Prosthetic Hip Joint and Prosthetic Knee Joint infections are responsible for most Prosthetic Septic Joints
  • Causes
  1. Early infection
    1. Staphylococcus epidermidis
  2. Late Infection
    1. Gram Positive Cocci (e.g. pneumococcus)
    2. Anaerobic Bacteria
    3. Pseudomonas
  • Exam
  1. See Septic Joint
  2. Precautions: Findings are often more subtle in infected prosthetic joints than in native joint infections
    1. May present with mild Joint Pain and low grade fever
    2. Joint erythema and swelling may be absent
  3. Evaluate skin overlying joint
    1. Lacerations
    2. Exposed bone or hardware
    3. Erythema
    4. Purulence
  4. Joint Exam
    1. Joint effusion
    2. Joint range of motion (active and passive)
  5. Other exam
    1. Neurovascular Exam
    2. Extremity compartments
  • Labs
  1. See Septic Joint
  2. Complete Blood Count with differential
  3. Inflammatory markers (CRP and ESR)
    1. Elevated levels increase suspicion for Septic Joint
  4. Arthrocentesis of prosthetic joint (Aspiration)
    1. Obtain in all suspected cases (and before Antibiotics are started)
    2. Ultrasound guided Arthrocentesis facilitates successful procedure
      1. See Knee Arthrocentesis for prosthetic Knee Aspiration technique
    3. Tests
      1. Synovial Fluid Cell Count with differential (esp. Neutrophil percentage)
      2. Synovial FluidGram Stain and culture
      3. Synovial FluidLeukocyte esterase (see diagnosis below)
      4. Synovial FluidLactic Acid (>5.6 mmol/L is positive in prosthetic and native joints)
      5. Synovial Fluid Lactate Dehydrogenase (>250 units/L is positive in prosthetic and native joints)
    4. Findings suggestive of infection differ from native joints
      1. Prosthetic joint WBC Count >1,100/uL (contrast with 3000/uL for native joints)
      2. Prosthetic joint PMN percent >64%
  5. Synovasure Lateral Flow Test
    1. Detects human alpha defensins released by activated Neutrophils
    2. Positive test suggestive of Bacterial periprosthetic infection
  6. Saline Load Test
    1. Indicated in suspected occult Traumatic Arthrotomy (open wound with joint violation)
  • Imaging
  1. Joint XRay
    1. May demonstrate joint free air or Localized Edema
    2. Also evaluate for associated Trauma
      1. Periprosthetic Fracture
      2. Loose joint implants
  2. Nuclear scan
    1. Negative Nuclear scan excludes septic prosthetic joint
  3. Pet Scan
  4. Avoid CT Scan or MRI in infected prosthetic joint
    1. Does not distinguish infected prosthetic joint from other causes of pain
    2. Exception: CT for open wound and concern for joint violation evaluation (Traumatic Arthrotomy)
      1. See Traumatic Arthrotomy
  • Diagnosis
  1. Major Criteria
    1. Two joint cultures positive for same organism
    2. Sinus tract communicating with joint
  2. Minor Criteria
    1. Score 2: Serum C-RP > 10 mg/L or D-Dimer > 860 ng/ml
    2. Score 1: Serum ESR >30 mm/hour
    3. Score 3: Synovial WBC >3000/uL or Leukocyte esterase (2+)
    4. Score 3: Synovial Alpha-defensin (signal to cutoff ratio >1)
    5. Score 2: Synovial PMNs >80%
    6. Score 1: Synovial C-RP >6.9 mg/L
  3. Intraoperative Criteria (optional)
    1. Score 3: Histology positive
    2. Score 3: Purulence
    3. Score 2: Single Culture Positive
  4. Interpretation
    1. Infection
      1. Either major criteria positive OR
      2. Minor Criteria Score >6 OR
      3. Minor AND Intraoperative Criteria >6 (with Minor Score at least 2)
    2. Inconclusive
      1. Neither major criteria present AND
      2. Minor AND Intraoperative Criteria 2 to 5 (with Minor Score at least 2)
    3. No Infection
      1. Neither major criteria present AND
      2. Minor Criteria 0 to 1 (or combined with intraoperative criteria <3)
  5. References
    1. Parvizi (2018) J Arthroplasty 33(5): 1309-14 [PubMed]
  • Management
  1. See Septic Joint
  2. Emergent orthopedic Consultation
    1. Early stage infections may respond to irrigation and Debridement
    2. Late stage infections typically require exchange of Arthrocentesis (e.g. TKA)
  3. Empiric therapy before culture results
    1. Option 1 (2 drug regimen)
      1. Drug 1: Vancomycin
      2. Drug 2: Ciprofloxacin, Aztreonam, or Gentamycin
    2. Option 2 (2 drug regimen)
      1. Drug 1
        1. Ciprofloxacin 750 PO bid or
        2. Ofloxacin 200 mg PO tid
      2. Drug 2: Rifampin 900 mg PO qd
  4. Ciprofloxacin and Rifampin sensitive by culture
    1. Option 1 (2 drug regimen)
      1. Drug 1: Ciprofloxacin or Ofloxacin
      2. Drug 2: Rifampin 900 mg PO qd
    2. Option 2 (2 drug regimen)
      1. Drug 1: Oxacillin 2 grams IV every 4 hours
      2. Drug 2: Rifampin 900 mg PO qd
  5. Ciprofloxacin or Rifampin resistance by culture
    1. Vancomycin and
    2. Rifampin (if sensitive)
  • References
  1. Buddendorff (2021) Crit Dec Emerg Med 35(12): 18-9
  2. Voorhees and Riveros (2024) Crit Dec Emerg Med 38(3):22-3
  3. Earwood (2021) Am Fam Physician 104(6): 589-97 [PubMed]