In the developed world, vertebral osteomyelitis is most commonly acquired hematogenously. Staphylococcus aureus is the most frequent isolate, followed by streptococcus and gram-negative organisms. Progressive pain over a period of months is typical of vertebral osteomyelitis. Spinal epidural abscesses are caused by the same organisms and may result from hematogenous seeding of the epidural space or extension from vertebral osteomyelitis.
For most patients who have vertebral osteomyelitis without epidural abscess, empirical antibiotic treatment can be delayed (but not by more than 24 hours) until biopsy is performed to obtain a microbiologic diagnosis; operative management is not required. If MRI and clinical findings are consistent with compression of the spinal cord by an epidural abscess, immediate neurosurgical consultation and possible mechanical decompression are warranted.
New England Journal of Medicine - Vol. 359, No. 6, August 7, 2008