Facet joint septic arthritis masquerading as endplate osteomyelitis/discitis (spondylodiscitis)

Case contributed by Chris O'Donnell
Diagnosis certain


High grade fever with elevated CRP and white cell count. Severe pain in left lower back. Weak legs ? epidural abscess.

Patient Data

Age: 25
Gender: Male

Dessication and bulging of the L5/S1 disc.  Severe central canal stenosis at L4/5 associated with gross bilateral L4/5 facet arthropathy and edema (bone and soft tissue) around the left L4/5 facet joint extnding inot the adjacent psoas and paravertebral muscles.  Note diffuse gadolinium enhancement.  No endplate or disc enhancement, or edema

Marked bilateral L4/5 facet joint widening, erosion of articular bone and cyst formation gretaer on the left.

Case Discussion

Fever, elevated white cell count and low back pain is usually associated with spondylodiscitis but can also be the presentation of facet septic arthritis as in this case.  Sepsis is presumed to have been blood-borne with bacteria settling in pre-existing severely degenerate joints.  Consider in this young patient - underlying diabetes or illicit IV drug use.

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