Fraser, Osti, Vernon-Roberts Iatrogenic discitis: The role of prophylactic antibiotics in prevention and treatment Spine 14: 1025-1032, 1989Osti, Fraser, Vernon-Roberts Discitis after discography: the role of prophylactic antibiotics JBJS 72B: 271-274, 1990Lyndholm and Pylkkanen Discitis following removal of intervertebral disc Spine 7: 618-622, 1982
Incidence
seen in discectomy, discography, chemonucleolysis, percutaneous nucleotomy, lumbar punctureafter open discectomy: 0-2.8%chemonucleolysis: up to 2%discography: 2.7% without and .7% with stilleted needles0% if contrast mixed with antibiottic
Aetiology
bacterial contamination
Pathology
- bacteria introduced into disc
- progressive thinning of end plate with immature granulation tissue forming on the vertebral side of the end plate at 1 wk
- by 3 wks the end plates are breached and nuclear material herniates into the vertebral body – at this stage bacteria are destroyed in a florid vascular response
- by 6 wks new bone is forming , disc material is replaced by granulation tissue
Clinically
fever – usually notpain – severe, disabling, present at restmuscle spasm, posture abnormal
Investigation
Bloods:ESR upWCC usually normalcultures usually negative
radiology:plain films initially normaldisc narrowing at ~ 2-3 wksend plate erosions at ~ 6 wks
bone scanCTMRI
Treatment
Prophylaxissterile techniqueantibiotics
Antibiotics are unable to arrest the progression of discitis once the condition is established – however once the end plate is penetrated, antibiotics may have a role in prevention of vertebral osteomyelitisrestsupport- may need to be for 6-8 mthsanterior clearance and fusion if symptoms demand
Prognosis
is a slowly resolving process in the majority discitis following open discectomy follows a more refractory course with most pts having disabling symptoms after 5 yrs