Discitis
Etiology
Iatrogenic: following surgery or disc cannulation
Can be primary in childhood
Spontaneously occuring spinal infections in adults involving the discs are due to osteomyelitis of the vertebral body – probably beginning in the end plate, not discitis
Childhood Discitis
Menelaus M.B. Discitis JBJS 46B: 16-23, 1964
Wenger etal The spectrum of intervertebral disc space infection in children JBJS 60A:100-108, 1978
Incidence
Rare
Clinically
Back pain
Difficulty walking or sitting
May be assoc with fever, malaise
May be preceded by URTI etc
Reduced motion, muscle spasm, abnormal posture
Investigation
Blood
ESR up
WCC usually normal
Blood cultures – +ve in 50%
> 6 wks post onset of symptoms organisms do not appear to isolated from blood cultures
Radiology
early normal
later – disc narrowing
progressive end plate lesions
erosion into the vertebral body
latest – fusion rare, very little residual disc narrowing
Treatment
Rest – until no pain or limitation of motion, and until ESR normal
Antibiotics- indicated if febrile, +ve blood cultures, +ve biopsy, IV until pt comfortable, then oral for 3 more wks
Prognosis
Good- spontaneous recovery is almost the rule
Adult Discitis
Incidence
Discectomy, after open discectomy: 0-2.8%
Discography, 2 % without and 0.7 % with stilleted needles (0 % if Ab’s mixed in)
Chemonucleolysis, up to 2 %
Percutaneous nucleotomy
Lumbar puncture
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 – bacteria are destroyed in a florid vascular response
By 6 wks new bone is forming , disc material is replaced by granulation tissue
Clinically
Pain – severe, disabling, present at rest
Muscle spasm
Posture abnormal
Investigation –
Blood
ESR up
WCC usually normal
Cultures usually negative
Radiology
Plain films initially normal
Disc narrowing at 2-3 wks
End plate erosions at 6 wks
Bone scan
CT
MRI
Treatment
Prophylaxis – sterile technique
Antibiotics are unable to arrest the progression of discitis once the
condition is established
Once the end plate is penetrated, antibiotics may have a role in prevention of vertebral osteomyelitis
Rest – support- may need to be for 6-8 mths
Anterior clearance and fusion if symptoms demand
Prognosis
IV or intradiscal antibiotics during discography have not been conclusively shown to decrease the rate of discitis over sterile technique alone.
Both single- and double-needle techniques when used with stylettes are superior to nonstyletted techniques.
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