Spinal Infections
Himanshu Sharma
Spinal Infections
Objectives
•
Epidemiology
•
Pathology
•
Clinical features
•
Management
•
Prognosis
Spinal Infections
Epidemiology
• 2 - 4% all cases of “osteomyelitis”
• Rare: 1 in 250,000/yr but rising incidence
• Post-op discitis = 2-3%
• Pre-antibiotic mortality = 25-70%
• Delayed diagnosis common (50%+ > 3/12)
Spinal Infections
Levels
Spondylodiscitis / facet disease
•
Lumbar
(59%)
•
Thoracic
(33%)
•
Cervical
(8%)
Epidural abscess (in 7%)
•
Cervical
•
Thoracic
•
Lumbar
(6-18%) anterior
Spinal Infections
Risk Factors
•
Peak incidence 7th decade
•
Concurrent illness/infection
Diabetes
Obesity
Immunosuppressed
Malnutrition
Steroid therapy
Irradiation
UTI
•
Invasive procedures/ trauma
•
Smoking
Spinal Infections
Pathology (1)
• Organisms
S aureus 30 -50% cases
Gram-negatives – UTI, Chest, Skin ulcers
Opportunistic in immune paresis
IVDA
• Route of spread
Haematogenous
Direct extension
Post-operative
Spinal Infections
Pathology (2)
• Vertebral metaphyses (end plate region)
= end-arteriole blood supply (filter)

Septic emboli
• Direct spread from implantation

Secondary spread to discs, paraspinal
tissues and spaces
Spinal Infections
Clinical Features
•
Pain and focal tenderness
90%
•
Fever
61%
•
Root symptoms/signs
60%
•
Abnormal neurology
20%
Also: deformity, muscle spasms, meningism, sinus,
and unexplained septicaemia
Investigations
•
•
•
•
•
•
FBC
ESR
CRP
Blood & Urine cultures
Nutritional status
Biopsy
Spinal Infections
Diagnosis
• Lab tests
 White cell count
40-50%
 ESR / CRP
80-90%
Positive Blood Culture
20-25%
• Imaging
• Biopsy
Spinal Infections
Plain radiological findings
•Vertebral metaphyseal blurring
(osteolysis)
•Loss of disc height
•Endplate blurring
•Subchondral reactive bone
formation
•Bone destruction (and deformity)
•Soft-tissue shadows e.g.psoas
abscess
Pyogenic
discitis/osteomyelitis
Bad disc = Good news
Spinal Infections
Imaging Studies - Isotopes
• Detect earlier than plain films
• High sensitivity / specificity
e.g. gallium + Tc = 95% accurate
• Little structural information
• False negatives in neutropenics
(gallium)
• False negatives in bone infarction (Tc)
Pyogenic spinal infections
imaging studies - CT
• delineate bony margins / involvement
• soft-tissue invasion
• poor for outlining neural elements
• risk of spread if combine with myelography,
but can obtain CSF
• 3D/MPR useful for pre-op planning of
reconstruction
Spinal Infections
Differential Diagnosis
• Granulomatous disease
• Metastases/Myeloma
• Degenerative disease
• Osteoporosis
• Local Scheuermann’s
• Spondyloarthropathies
> 95% accuracy
T2=  signal
T1=  signal
Ring enhancement
Spinal Infections
Biopsy
Biopsy (for identification of the causative organism)
• Closed needle biopsy (guided)
– 68 - 86% accuracy (false negative 30%)
• Open biopsy
– > 80% accurate (false negative 14%)
• Special lab techniques (DNA PCR, etc)
Biopsy principles
• Biopsy material should be sent to microbiology for
gram stain & acid-fast stain, aerobic, anaerobic,
fungal and mycobacterial cultures and for
histopathological examination.
Spinal Infections
Treatment Goals
• Establish diagnosis
• Clear infection and prevent recurrence
• Pain relief
• Protect / restore neurological function
• Maintain / restore spine stability
Changed Battlefield
• Territory
– Patients
• Weapons
– Antibiotics
–Surgery
• Enemy
– Microbiology
Territory - changed
• Patient
•
•
•
•
•
•
Population Greying
Type 2 DM
Cancer
Steroids
HIV
Drug Abuse
• Iatrogenic
Immunosuppression
Transplants
Dialysis
Enemy - changed
• More Resistant Strains of Bacteria
• Hospital Acquired Infection
• More previously unsuspected causes
Weapons • Antimicrobials
• Type and Scope of Surgery
Why is it important?
• Consequence of
Inappropriate Management
• Multiple Surgery
• Pain
• Paralysis
• Death
• Financial Cost
• Causes of Inappropriate
Management
• Lack of awareness
• Empirical Antibiotics
• Inappropriate /Inadequate
Surgery
Spinal Infections
Treatment (1)
Antibiotics
– sensitivities
– adequate dose (iv then oral)
– ensure MBC reached
– adequate duration (> 6 weeks)
– monitor response (clinical/ indices/ imaging)
– toxicity profile and monitoring
Spinal Infections
Treatment (2)
Immobilisation
– bed rest
– moulded orthoses (low thoracic / lumbar)
– halo-vest or orthosis (cervical / high thoracic)
9/12
Pyogenic spinal infections