Spinal infections

1. Spinal Infections
Department of Neurosurgery
Dr RE Anto

2. Contents
• Epidemiology
• Risk factors
• Pathophysiology
• Microbiology
• Clinical presentation
• Diagnosis
• Management
• Non surgical management
• Poor outcome predictors
• Literature review
• References

3. Introduction
• Multidisciplinary team
• Nomenclature can be complex
• Causative pathogen
• Underlying pathophysiology
• Anatomical location

4. Terminology
Microorganisms 2020, 8, 476; doi:10.3390/microorganisms8040476

5. Epidemiology
• Overall incidence 2.2/100 000 per year
• Bimodal age peak: very young and very old
• Male > Female (2:1)
• Most common type – primary pyogenic spondylodiscitis
• Most common spinal segment
• Lumbar (58%)
• Thoracic (30%)
• Cervical (11%)

6. Risk factors
• Immunocompromised
• HIV; Corticosteroid therapy; Malignancy; Diabetes
Mellitus; Renal Failure
• Age > 50
• IV drug use
• Degenerative spine disease
• Prior spinal surgery
• Intravascular/orthopedic implants

7. Pathophysiology
1. Haematogenous
2. Contiguous
3. Direct inoculation
1
2 3

8. Haematogenous
• Most common
• Venous theory: Batson’s Venous Plexus
Retrograde flow from the pelvic venous plexus to the perivertebral
venous plexus via valveless veins
• Arterial theory:
Bacteria can become lodged in the end-arteriolar network near the
vertebral end plate.

9. BATSONS PLEXUS
ARTERIAL SUPPLY

10. Primary Source
• Urinary tract infection
• GIT infections
• Otitis media
• Dental abscess
• Infective endocarditis
• Respiratory infections
• Infected intravascular lines
50% of cases no primary source identified.

11. • Contiguous spread:
From an adjacent structure
• Aorta
• Esophagus
• Bowel
• Direct inoculation:
• Penetrating trauma
• Spinal surgery
• Spinal procedures
• Myelography
• LP
• Translumbar aortagraphy
• Chemonuceolysis
• Discography
• Facet joint infiltration

12. Microbiology
• Staph aureus (most common – 45-50%)
• Urinary tract instrumentation: Enteric gram-negative
bacilli
• Non-pyogenic streptococci
• Diabetes mellitus: Pyogenic streptococci, including
groups B and C/G
• IV Drug use/Intravascular sepsis: Pseudomonas, CNSA,
Candida spp
• 3rd world: Tuberculous infection
• Immunocompromised: Fungal
Staph Aureus
Mycobacterium TB

13. Clinical Presentation
• Back pain
• Pain aggravates at night
• Fever (30%)
• Neurological deficit (10-20%)
• Radiculopathy
• Paresthesia
• Weakness
• Bowel/Bladder dysfunction

14. Diagnosis
• Physical signs
• Percussion tenderness
• Spinal deformity
• Distended bladder
• Flank pain
• Laboratory
• WCC (<50% - not sensitive)
• ESR (elevated in 90%)
• CRP (serial monitoring)
• Interferon Gamma Release Assay
(TB)
• HIV status (if suspected)
• Blood culture (positive only 20-
30%)

15. Imaging - Xray
• Findings can be delayed by weeks
• 1st few days: Paraspinous soft tissue
swelling (loss of psoas shadow)
• 7-10 days: Disc space narrowing and disc
destruction
• 10-21 days: Endplate erosion or sclerosis
• Local osteopenia

16. CT
• Useful for bony abnormalities, soft
tissue abscesses and to assess extent of
bony involvement
• Changes can be seen before Plain X-rays
• May miss spinal epidural abscesses

17. MRI
• Gold standard
• High sensitivity (96%) and high specificity
(93%)
• Low T1 signal (high signal on T2) throughout
disc and in adjacent vertebral bodies
• Thinning, fragmentation of dark line of
vertebral end-plates.
• Gadolinium → diffuse enhancement in areas
showing signal change

18. • In degenerative disk disease
• Changes are less uniform
• Disk is desiccated and bone destruction is absent
• No paravertebral soft-tissue masses
• Specific MRI findings of TUBERCULOUS spondylitis:
• Thin and smooth enhancement of the abscess wall
• Well-defined paraspinal abnormal signal
• Disc space may be relatively spared

20. T1 contrast enhanced MRI (osteomyelitis lumbar spine)

21. Discitis lumbar spine and epidural abscess on T2-weighted MRI

22. Radio-isotope studies
• Labeled-leukocyte scans
• Three-phase bone scintigraphy -
technetium
• Gallium imaging
• Positron emission tomography (PET)
using FDG

23. Biopsy
• Needle biopsy: (Yield 45%)
• CT-Guided vs Fluoroscopy
• Ideally before initiation of empiric
antibiotics
• Samples should be sent for aerobic,
anaerobic, mycobacterial, and fungal
cultures and histopathology
• Open biopsy: (Yield 70%)
• Inaccessible by standard closed
techniques
• Marked structural damage
• Marked neurological deficit requiring
surgery
Open Forum Infect Dis. 2018 Mar 10;5(3):ofy037

24. Eur Spine J (2013) 22:2787–2799

25. Goals of Management
• Establish a dx
• Identify a pathogen
• Eradicate the infection
• Prevent or minimize neurological involvement
• Maintain spinal stability
• Provide adequate nutritional state to combat
infection

26. Non-Surgical Management
• Immobilization (Bed rest + Brace)
• Improve pain control
• Prevent deformity
• Analgesia
• Optimize nutrition
• Empiric IV Antibiotics 4-6/52 (tailor to specific organism)
• Then convert to Oral treatment 6-8/52
• Monitor clinical, laboratory and radiological response.

27. Surgical indications
• Obtain tissue diagnosis
• Failed medical therapy
• Presence/development of neurological signs
• Drainage of abscess causing neurological deficit
• Progressive deformity
• Spinal instability

28. Approach
• Depends on the location of the infection
and the intended purpose of the surgery
• Anterior approach:
Most commonly used to maximize
access to infected tissue
• Posterior approach:
May also be considered in some
instances

29. Poor outcome predictors
Eur Spine J (2013) 22:2787–2799

30. Literature on surgery for spinal infection
Eur Spine J (2013) 22:2787–2799

31. Summary of the literature
• Early surgical treatment for any neurological deficit or for sepsis
• Absolute indication for surgery: spinal instability
• Relative indication for surgery: epidural abscess without neurological
deficit and poor pain control
• Anterior approaches for extensive bone destruction gives earlier
mobilization, improved deformity correction and faster fusion.
• Use of metallic implants (esp titanium) is safe in infection
Asian Spine Journal Vol. 5, No. 3, pp 155~161, 2011

32. References
• Tsantes AG, et al. Spinal Infections: An Update. Microorganisms. 2020;8(4):476.
• Duarte RM, Vaccaro AR. Spinal infection: state of the art and management
algorithm. Eur Spine J. 2013 Dec;22(12):2787-99
• Sundararaj GD, et al. The use of titanium mesh cages in the reconstruction of
anterior column defects in active spinal infections: can we rest the crest?. Asian
Spine J. 2011;5(3):155-161.
• Chong BSW, et al. Epidemiology, Microbiological Diagnosis, and Clinical Outcomes
in Pyogenic Vertebral Osteomyelitis: A 10-year Retrospective Cohort Study. Open
Forum Infect Dis. 2018 Mar 10;5(3):ofy037.

33. Thank you