Spinal Infections Himanshu Sharma Spinal Infections Objectives Epidemiology
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 7 th 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 • 3 D/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 T 2= signal T 1= signal Ring enhancement
Spinal Infections 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)
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Pyogenic spinal infections
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