From the Guidelines
It is recommended to obtain a biopsy before starting antibiotics for suspected vertebral osteomyelitis, as this approach maximizes the likelihood of identifying the causative organism and allows for targeted antibiotic treatment. Ideally, blood cultures should be drawn first, followed by image-guided biopsy of the affected vertebral area, all before initiating antibiotic therapy 1. This sequence is crucial for targeted antibiotic treatment, which is typically needed for 6 weeks, as stated in the 2015 IDSA clinical practice guidelines for the diagnosis and treatment of native vertebral osteomyelitis in adults 1.
However, exceptions exist for patients with sepsis, neurological deficits, or hemodynamic instability, where empiric antibiotics should be started immediately after blood cultures are obtained, without waiting for biopsy results. In these urgent cases, reasonable empiric antibiotic choices include vancomycin plus ceftriaxone to cover common pathogens like Staphylococcus aureus and gram-negative organisms.
The rationale for obtaining cultures before antibiotics is that antimicrobial therapy can rapidly sterilize the infection site, reducing diagnostic yield. A definitive microbiological diagnosis allows for targeted antibiotic therapy and helps avoid unnecessarily broad antimicrobial coverage that increases the risk of adverse effects and antimicrobial resistance. Although some studies suggest that recent antibiotic use may not affect the yield of biopsy cultures 1, the most recent and highest quality evidence still supports obtaining a biopsy before starting antibiotics for suspected vertebral osteomyelitis.
Key considerations in the diagnosis and treatment of vertebral osteomyelitis include:
- Obtaining blood cultures before initiating antibiotic therapy
- Performing image-guided biopsy of the affected vertebral area before starting antibiotics
- Starting empiric antibiotics immediately in patients with sepsis, neurological deficits, or hemodynamic instability
- Targeted antibiotic therapy based on culture and susceptibility results
- Avoiding unnecessarily broad antimicrobial coverage to minimize adverse effects and antimicrobial resistance.
From the Research
Vertebral Osteomyelitis Treatment
- The decision to wait for antibiotics before biopsy for vertebral osteomyelitis depends on various factors, including the severity of the infection and the patient's overall health 2.
- Current consensus does not advocate for empirical antibiotic treatment unless patients exhibit signs of neurological impairment or severe sepsis 2.
- Identifying the causative organism is crucial for guiding appropriate antimicrobial therapy, and a biopsy may be necessary for microbiological diagnosis, either by computed tomography (CT)-guided needle biopsy or open surgery 3.
- In some cases, vancomycin monotherapy may be insufficient to prevent or reverse the progression of hematogenous MRSA vertebral osteomyelitis, and alternative therapeutic approaches may be necessary 4.
Antibiotic Regimens
- The selection of an appropriate empiric antibiotic regimen for suspected hematogenous vertebral osteomyelitis should be based on the antimicrobial susceptibility profiles of isolated bacteria 5.
- Vancomycin combined with a broad-spectrum cephalosporin or fluoroquinolone may be appropriate for empiric treatment of HVO, while fluoroquinolone-based oral combinations may not be suitable due to frequent resistance 5.
- Ceftriaxone is an effective and safe agent for the treatment of osteomyelitis, but questions remain about the cure rate against S. aureus osteomyelitis and the optimal duration of treatment 6.
Diagnostic Strategies
- Magnetic resonance imaging (MRI) is the method of choice for the radiological diagnosis of vertebral osteomyelitis, and blood cultures belong to the standard procedures 3.
- A biopsy is generally warranted for microbiological diagnosis in cases of negative blood cultures, either by computed tomography (CT)-guided needle biopsy or open surgery 3.