Description:

  • Constitutes 1% of pyogenic skeletal infections
  • Pathogenic organisms can infect vertebral bodies, intervertebral discs, or the spinal canal
  • Spine infected through local extension from adjacent infection or else from seeding of distant organ hematogenously or via lymphatic system
  • Bacteria can be directly introduced by surgery, trauma, intravenous or intradural injection or catheterization
  • Most frequently cultured organisms are:
  • Staphylococcus aureus
  • Pseudomonas aeruginosa
  • Salmonella should be considered in patients with sickle cell disease
  • Mycobacterium tuberculosis is seen in less developed populations and in prison populations (Pott’s disease)
  • Spinal sepsis is common in:
  • Adolescents
  • Elderly
  • IV drug users
  • Patients with diabetes or renal failure
  • Patients who have undergone spinal surgery
  • Recent acute systemic infection, especially S.aureus
  • Osteoporosis has been implicated as predisposing factor due to increased blood flow

Signs/Symptoms:

  • Pyogenic osteomyelitis
  • Acute spontaneous back pain, +/- fever & weight loss
  • Significant percussion tenderness posteriorly over affected vertebral segments
  • Paraspinal muscle spasm in 90% of patients
  • Fevers present in <50% patients Lab test results often equivocal Elevated WBC’s in only 42% patients ESR elevated in >90% cases but non-specific
  • Diagnosis relies upon high index of suspicion

Imaging:

  • Radiographic findings lag behind symptomatic progression of disease
  • MRI with gadolinium contrast is gold standard for early detection
  • Bone scan may be useful in diagnosis
  • Plain radiographs often negative, late findings (10 days to 2 weeks) include disc space narrowing and endplate erosion
  • Tubercular osteomyelitis: plain films demonstrate anterior vertebral body destruction with sparing of intervertebral disc

Treatment:

  • Identification of responsible organism is key to treatment
  • After confirmation of organism by blood culture or biopsy specimen, appropriate IV antibiotics administered for 6 weeks
  • Short-term bed rest for pain management
  • Successful nonoperative treatment most likely in patients < 60 years old, immunocompetent, infection by S. aureus, decreasing ESR as response to IV antibiotics
  • Surgical treatment required to moderate advanced destruction of spine with instability, neurologic compromise, or failure to respond to IV antibiotics
  • Surgical treatment consists of anterior debridement and stabilization with autologous structural bone grafting with possible posterior pedicle screw fixation and fusion
  • Antibiotic impregnated polymethylmethacrylate cement may be used as a temporary spacer
  • New minimally invasive techniques may prove to be excellent tools for management of spinal infections