Spinal Infection

1. See Also
   1. Osteomyelitis
2. Epidemiology
   1. Incidence: 0.2 to 2.8 cases per 10,000 per year
   2. Peak ages affected: 60 to 70 years
3. Pathophysiology: Sites of Spinal Infection
   1. Most cases involve thoracolumbar spine
   2. Anterior Epidural Abscess (20%)
      1. Associated infections
         1. Disk space infection (Discitis)
         2. Vertebral Osteomyelitis
      2. Blunt trauma and associated hematoma infection
      3. Direct extension from adjacent infection
         1. Retropharyngeal Abscess
         2. Retroperitoneal abscess
   3. Posterior Epidural Abscess (80%)
      1. Distant source (Cellulitis, dental, Pharyngitis)
4. Etiology
   1. Acute Infection (within 5-10 days)
      1. Staphylococcus aureus (most common)
      2. Actinomycosis (rare)
   2. Chronic Infection (within 3-6 months)
      1. Other indolent infections
      2. Fungus
      3. Tuberculosis (Pott's Disease)
         1. Vertebral collapse
         2. Sharply angulated spinal deformity
5. Risk Factors
   1. Idiopathic without risk factors in 20% of cases
   2. Intravenous Drug Abuse
   3. Immunodeficiency
      1. AIDS
      2. Chronic Renal Failure (esp. Dialysis)
      3. Diabetes Mellitus
      4. Alcoholism
      5. Malignancy
   4. Recent spinal procedure
      1. Spinal surgery
      2. Epidural Anesthesia
   5. Recent back trauma
   6. Concurrent infectious sources
      1. Genitourinary infection
      2. Skin Infection
      3. Poor Dentition (Associated with Actinomyces)
6. Symptoms
   1. Fever
   2. Rigors
   3. Malaise
   4. Neurologic compromise
      1. Bowel or Bladder dysfunction
      2. Extremity weakness
7. Signs: Focal tenderness at involved spinous process
   1. Associated with secondary muscle spasm
   2. Pain not relieved with rest
   3. Pain provoked by standing and bearing weight
8. Labs
   1. Complete Blood Count with Leukocytosis
   2. Erythrocyte Sedimentation Rate (ESR) increased
   3. C-Reactive Protein (C-RP) increased
9. Imaging
   1. Gadolinium-enhanced Spine MRI
   2. CT with Myelography
10. Diagnosis
    1. CT-aspiration or open biopsy
11. Precautions
    1. Evaluate for Cauda Equina Syndrome
12. Management (Adults)
    1. Neurosurgery consultation
    2. Surgical decompression
       1. Endoscopy-assisted surgery
       2. Percutaneous drainage
    3. Base antibiotics on biopsy
       1. Primary empiric antibiotics
          1. Nafcillin or Oxacillin 2 grams IV q4 hours or
          2. Cefazolin 2 grams IV q8 hours
       2. Alternative empiric antibiotics
          1. Vancomycin 1 gram IV q12 hours
13. Prognosis: Positive prognostic indicators
    1. Age under 60 years
    2. Cord symptoms (e.g. Bladder dysfunction) <72 hours
    3. No comorbid conditions
    4. Thecal sac compression <50%
14. Complications
    1. Cauda Equina Syndrome
    2. Meningitis
15. References
    1. Chao (2002) Am Fam Physician 65(7):1341-6