Treatment of Pyogenic Spondylodiscitis
Saturday, December 10, 2022 9:53 AM
KEY CONCEPTS
• incidence of pyogenic vertebral discitis/osteomyelitis is increasing
• at risk : immunocompromised patients (hemodialysis, IV drug users, and diabetics)
• MRI : initial imaging
• Nonop Tx ? 6w IV AB + 3m PO (optional)
• Surgical indications ? failure to secure a microbiologic diagnosis, neurological compromise through epidural compression, segmental instability, deformity, and
treatment failure
• Successful débridement and stabilization rely heavily on anterior column stabilization
INTRODUCTION
• nonmycobacterial PVDO most commonly caused by hematogenous spread of a distant infection
• occasionally -> contiguous spread (soft tissue or visceral infection pyelonephritis)
• recurrence is seen in 14% of the cases.(secondary to immunocompromise or failure to clear the infection from the avascular disk)
PRESENTATION AND DIAGNOSIS
• Back pain : most common symptom . followed by fever
red flags ? Fever, weight loss, neurological deficit, immunosuppression, and intravenous drug use
• Symptoms attributable to neural element compression (motor deficit, radiculopathy, urinary or bowel control dysfunction, etc.) are present initial y in only one-
third of patients
• Pain ? inflammatory nature - present while supine, and exacerbated by minimal motion even in bed
• The lumbar spine is the most affected segment (58%), followed by the thoracic (30%) and cervical (11%) segments
• CT may be complemented by a combination gallium/technetium 99m scan or PET
• Myelograms are typically contraindicated with suspected infection
• Peripheral blood cultures have been reported to be positive in 30%–78% of cases of PVDO
• If the source infection is not immediately evident, echocardiogram and dental survey should be considered
• MRI characteristics of PVDO ? disk-based lesion with decreased T1 and increased T2 signal representing fluid and associated marrow edema, with gadolinium
enhancement
• Noninfectious ddx ? dialysis-related spondyloarthropathy (DSA), spinal neuropathic arthropathy (Charcot spine), gout, and calcium pyrophosphate deposition
disease
• DSA and Charcot spine : lack the multicompartmental features of PVDO
• DSA is a unique type of amyloidosis caused by the deposition of β2-microglobulin, affecting primarily the wrists, hips, knees, and spine
• Charcot spine
a rare, progressive destructive lesion of the spine also centered around the disk and secondary to loss of proprioceptive and nociceptive sensation
imaging features ? “the six Ds”: distention (soft tissue mass), density (bone density is preserved), disorganization (altered articular contour with incongruity of
the joint), debris (osseous fragments), dislocation, and destruction
• Gout and calcium pyrophosphate deposition disease -> involvement of the posterior spinal structures
• Identification of bloodstream infection by a known associated organism (Staphylococcus aureus, Staphylococcus lugdunensis, or Brucella) along with typical spinal
imaging findings is usually considered enough for diagnosis
• Disk sampling is also not recommended in patients with subacute discitis with positive serology for Brucella and patient residence in an endemic area, or typical
findings of mycobacterial spinal infection (subacute, multilevel, multiphase disease in the thoracic area with occasional spontaneous healing) with a positive
purified protein derivative test or interferon-γ release assay
• In the case of a nondiagnostic biopsy or if a skin contaminant is isolated (Propionibacterium, Corynebacterium, or coagulase-negative Staphylococcus—except
S. lugdunensis), a second aspiration biopsy may be performed or the failure to isolate an organism can be considered an indication for surgery
NONOPERATIVE TREATMENT
• Prolonged intravenous antibiotic therapy is the mainstay of treatment
• The antistaphylococcal drug of choice is oxacil in, but methicil in-resistant Staphylococcus requires the use of vancomycin
• PO indication ? in the case of severely immunocompromised patients, an elevated burden of infection, or if instrumentation was implanted
• Treatment response should be assessed weekly with inflammatory markers
• CRP tends to respond faster than ESR
• healed discitis usually presents with vertebral body fusion
• Postinfectious kyphotic deformities up to 20 degrees are usually well tolerated even in the thoracolumbar transition
• MRI is not recommended for assessing the response
chapter 323 Page 1
Saturday, December 10, 2022 9:53 AM
KEY CONCEPTS
• incidence of pyogenic vertebral discitis/osteomyelitis is increasing
• at risk : immunocompromised patients (hemodialysis, IV drug users, and diabetics)
• MRI : initial imaging
• Nonop Tx ? 6w IV AB + 3m PO (optional)
• Surgical indications ? failure to secure a microbiologic diagnosis, neurological compromise through epidural compression, segmental instability, deformity, and
treatment failure
• Successful débridement and stabilization rely heavily on anterior column stabilization
INTRODUCTION
• nonmycobacterial PVDO most commonly caused by hematogenous spread of a distant infection
• occasionally -> contiguous spread (soft tissue or visceral infection pyelonephritis)
• recurrence is seen in 14% of the cases.(secondary to immunocompromise or failure to clear the infection from the avascular disk)
PRESENTATION AND DIAGNOSIS
• Back pain : most common symptom . followed by fever
red flags ? Fever, weight loss, neurological deficit, immunosuppression, and intravenous drug use
• Symptoms attributable to neural element compression (motor deficit, radiculopathy, urinary or bowel control dysfunction, etc.) are present initial y in only one-
third of patients
• Pain ? inflammatory nature - present while supine, and exacerbated by minimal motion even in bed
• The lumbar spine is the most affected segment (58%), followed by the thoracic (30%) and cervical (11%) segments
• CT may be complemented by a combination gallium/technetium 99m scan or PET
• Myelograms are typically contraindicated with suspected infection
• Peripheral blood cultures have been reported to be positive in 30%–78% of cases of PVDO
• If the source infection is not immediately evident, echocardiogram and dental survey should be considered
• MRI characteristics of PVDO ? disk-based lesion with decreased T1 and increased T2 signal representing fluid and associated marrow edema, with gadolinium
enhancement
• Noninfectious ddx ? dialysis-related spondyloarthropathy (DSA), spinal neuropathic arthropathy (Charcot spine), gout, and calcium pyrophosphate deposition
disease
• DSA and Charcot spine : lack the multicompartmental features of PVDO
• DSA is a unique type of amyloidosis caused by the deposition of β2-microglobulin, affecting primarily the wrists, hips, knees, and spine
• Charcot spine
a rare, progressive destructive lesion of the spine also centered around the disk and secondary to loss of proprioceptive and nociceptive sensation
imaging features ? “the six Ds”: distention (soft tissue mass), density (bone density is preserved), disorganization (altered articular contour with incongruity of
the joint), debris (osseous fragments), dislocation, and destruction
• Gout and calcium pyrophosphate deposition disease -> involvement of the posterior spinal structures
• Identification of bloodstream infection by a known associated organism (Staphylococcus aureus, Staphylococcus lugdunensis, or Brucella) along with typical spinal
imaging findings is usually considered enough for diagnosis
• Disk sampling is also not recommended in patients with subacute discitis with positive serology for Brucella and patient residence in an endemic area, or typical
findings of mycobacterial spinal infection (subacute, multilevel, multiphase disease in the thoracic area with occasional spontaneous healing) with a positive
purified protein derivative test or interferon-γ release assay
• In the case of a nondiagnostic biopsy or if a skin contaminant is isolated (Propionibacterium, Corynebacterium, or coagulase-negative Staphylococcus—except
S. lugdunensis), a second aspiration biopsy may be performed or the failure to isolate an organism can be considered an indication for surgery
NONOPERATIVE TREATMENT
• Prolonged intravenous antibiotic therapy is the mainstay of treatment
• The antistaphylococcal drug of choice is oxacil in, but methicil in-resistant Staphylococcus requires the use of vancomycin
• PO indication ? in the case of severely immunocompromised patients, an elevated burden of infection, or if instrumentation was implanted
• Treatment response should be assessed weekly with inflammatory markers
• CRP tends to respond faster than ESR
• healed discitis usually presents with vertebral body fusion
• Postinfectious kyphotic deformities up to 20 degrees are usually well tolerated even in the thoracolumbar transition
• MRI is not recommended for assessing the response
chapter 323 Page 1
