Spine iSAWE 11

Diagnosis and differentials

• Pyogenic discitis and vertebral osteomyelitis, with disc space narrowing and endplate erosion on both sides of the disc
• Tuberculous spondylitis, which tends to spare the disc early and spreads under the longitudinal ligaments
• Metastatic disease or myeloma, which usually spares the disc
• Modic endplate change, Charcot spine and brucellosis or fungal infection in at risk patients

Investigations

• FBC, ESR, CRP and two sets of blood cultures before antibiotics
• Ask about intravenous drug use, recent bacteraemia, diabetes, immunosuppression and endocarditis, with echocardiography if indicated
• MRI of the whole spine with gadolinium for disc enhancement, abscess, epidural extension and skip lesions
• CT guided biopsy for culture, histology, TB culture and PCR if blood cultures are negative
• Staph aureus is the most common organism

Treatment

• Withhold antibiotics in a stable patient until cultures or biopsy are taken
• Targeted intravenous antibiotics, then oral, for about 6 weeks total, monitored with CRP
• Brace for comfort
• Surgery for neurological deficit, epidural abscess with compression, instability or deformity, sepsis despite treatment and failed medical care
• Anterior debridement and reconstruction, often with posterior instrumentation

Children

• Discitis is most common in toddlers who refuse to walk or sit
• Blood cultures are often negative and biopsy is rarely needed
• Most settle with antibiotics and rest, and surgery is seldom required
• Disc space narrowing may persist and spontaneous fusion can follow

Related pages

• Pyogenic Spinal Infection
• Paediatric Discitis