What is the diagnosis and treatment for vertebral osteomyelitis (infection of the vertebral bone)?

From the Guidelines

Vertebral osteomyelitis should be treated with a 6-week course of antibiotics, with initial empiric therapy often including vancomycin and ceftriaxone, until culture results guide targeted therapy, as recommended by the 2015 Infectious Diseases Society of America (IDSA) guidelines 1. The condition typically presents with persistent back pain, fever, and elevated inflammatory markers.

• Key points to consider in the diagnosis and treatment of vertebral osteomyelitis include:
  • Obtaining blood cultures before starting antibiotics
  • Performing image-guided biopsy to identify the causative organism
  • Considering surgical intervention for patients with neurological deficits, spinal instability, significant bone destruction, or failure of antibiotic therapy
  • Providing pain management, bracing for stability, and physical therapy as adjunctive measures
  • Consulting with an infectious disease specialist to optimize antibiotic selection and duration
• The most common pathogen responsible for vertebral osteomyelitis is Staphylococcus aureus, although gram-negative bacteria and tuberculosis may also be responsible 1.
• The IDSA guidelines suggest that a 6-week course of antibiotics is sufficient for most patients, but some patients may require longer treatment durations, especially those with complicated infections or underlying comorbidities 2.
• It is essential to monitor patients closely with serial imaging and inflammatory markers to ensure resolution of the infection and prevent serious complications, such as spinal deformity, neurological deficits, or paralysis 1.

From the Research

Vertebral Osteomyelitis Overview

• Vertebral osteomyelitis is a rare but serious condition that can cause significant morbidity 3
• Methicillin-susceptible Staphylococcus aureus (MSSA) is the most common microorganism in native vertebral osteomyelitis 3
• Methicillin-resistant Staphylococcus aureus (MRSA) is also a common cause of vertebral osteomyelitis, particularly in cases of healthcare-associated infections 4

Antibiotic Treatment

• Empiric antibiotic therapy for suspected hematogenous vertebral osteomyelitis (HVO) should be initiated immediately in seriously ill patients and may be required in those with negative microbiological results 4
• Vancomycin combined with a broad-spectrum cephalosporin or fluoroquinolone may be appropriate for empiric treatment of HVO 4
• Ceftriaxone is an effective and safe agent for the treatment of osteomyelitis, including vertebral osteomyelitis 5
• Oral β-lactams may be safe for use in certain adult patients with MSSA vertebral osteomyelitis, but further evaluation is needed 3

Antibiotic Effectiveness

• Current clinically utilized antibiotics have limited effectivity against acute and chronic intracellular S. aureus infections in osteocytes, even at concentrations above their minimum inhibitory concentration (MIC) 6
• Rifampicin, levofloxacin, and linezolid reduced intracellular CFU numbers significantly in an acute model of osteocyte infection, but no treatment reduced the quantity of bacterial mRNA or prevented non-culturable bacteria from returning to a culturable state 6
• Vancomycin monotherapy may be insufficient to prevent or reverse the progression of hematogenous MRSA vertebral osteomyelitis, despite giving the appearance of success by conventional clinical and laboratory criteria 7

Treatment Considerations

• Long-term administration of parenteral and oral antibiotics with good bioavailability and bone penetration is required for therapy of vertebral osteomyelitis 3
• The duration of antibiotic therapy and the choice of antibiotics may vary depending on the patient and the hospital 3
• Risk factors for treatment failure include old age and failure to improve C-reactive protein levels at follow-up 3