Review Question - QID 1686

The clinical presentation is consistent with pyogenic vertebral osteomyelitis. A CT guided biopsy is the most appropriate next step in management to identify an organism and direct antimicrobial therapy.

Adult pyogenic vertebral osteomyelitis is usually seen from ages 50 to 60 years. Risk factors include IV drug abuse and diabetes. Staph aureus is most a common (50-65%) pathogen, but in IV drug users pseudomonas is also seen. In most cases bracing and long term antibiotic (6-12 weeks) therapy is effective treatment. Obtaining a causative organism, either through blood culture or a biopsy, is critical for good outcomes. Indications for surgery include neurologic deficits, progressive deformity, gross spinal instability, and persistent infection.

Tay et al. report that a prompt and accurate diagnosis of spinal infections requires a high index of suspicion in at-risk patients. They emphasize that an evaluation should be focused on identifying the organism and determining the extent of infection.

Carragee et al. reviewed 111 patients with pyogenic vertebral osteomyelitis, unrelated to spinal procedures, and found that risk factors included diabetes and other immune compromised states. The average age was 60. They found the most frequent infecting organism was Staphylococcus aureus (36%). Thirty-seven percent where caused by other organisms, such as Staphylococcus epidermidis, Propionibacterium acnes, and diphtheroid species. The most common hematogenous source for infection was the urinary tract.

Figure A shows a lateral view of the lumbar spine that demonstrates L 3-4 disc space narrowing (arrow) and end-plate irregularity. Figure B shows a sagittal T1-weighted images that demonstrate T1-hypointense signal (panel A - solid arrows) centered around the L3-4 interspace. Post gadolinium sagittal fat-suppressed T1-weighted images shows marrow (panel B - dashed arrows) and disc enhancement with endplate erosions.

Incorrect Answers:
Answer A: Physical therapy and supportive therapy (e.g., analgesia) would be encouraged in this patient, however the primary pathology needs to be addressed and managed initially before these measures are implemented.
Answer B: A CT guided biopsy is the most appropriate next step in management to identify an organism and therefore direct antimicrobial therapy
Answer C: There is no indication for open decompression and biopsy as this patient in neurologically intact.
Answer E: Repeat imaging alone would not be sufficient for the management of osteomyelitis.