Cervical facet joint septic arthritis: a case report

Abstract

Facet joint septic arthritis is a rare but severe infection with the possibility of significant morbidity resulting from local or systemic spread of the infection. Pain is the most common complaint on presentation followed by fever, then neurologic impairment. While the lumbar spine is involved in the vast majority of cases presented in the literature, the case presented here occurred in the cervical spine. The patient presented with a three week history of neck and left shoulder pain and was diagnosed by MRI when his pain did not respond to analgesics and muscle relaxants. The only predisposing factor was a history of diabetes mellitus and the infection most likely resulted from hematogenous spread. MRI is highly sensitive in diagnosing septic arthritis and it is the preferred modality for demonstrating the extent of infection and secondary complications including epidural and paraspinal abscesses as seen in this case. Without familiarity with this entity's predisposing factors, clinical symptoms and appropriate lab/imaging work up, many patients experience a delay in diagnosis. Treatment involves long term parenteral antibiotics or percutaneous drainage. Surgical debridement is reserved for cases with severe neurologic impairment. The incidence of facet joint septic arthritis is increasing likely related to patient factors (increasing number of patients >50 yo, immunosuppressed patients, etc), advancement in imaging technology, availability of MRI, and heightened awareness of this rare infection which is the aim of this case presentation.

Figures 1A

B. Contiguous axial T2 weighted MR images at C5-6. There is high T2 signal in the left facet joint space with adjacent bony destruction. Both images show fluid collections in the paraspinous tissues consistent with abscess (white arrows). Figure 1A shows direct extension of the infection into the epidural space (arrowhead) with abscess formation.

Figures 2A-C

Two contiguous axial (A and B) and a coronal (C) Tl weighted fat saturation post gadolinium images. Figure 2A shows bony destruction at the left C5-C6 facet joint with extension into both the epidural space and bilateral paraspinal soft tissues. Figure 2B shows paraspinal abscess formation (white arrow) and enhancement extending anteriorly into the prevertebral soft tissues. Figure 2C shows direct extension of the paraspinal abscess from the level of the left C5-C6 facet (black arrow).

Figures 3A, B

Sagittal T2 weighted images in the midline and left of midline. Figure 3A shows the epidural abscess (white arrow) with posterior mass effect on the cervical spinal cord at C5-C6. Figure 3B demonstrates the paraspinal abscess and adjacent high T2 signal in the musculature consistent with inflammation.

Figure 4

Axial CT scan in bone windows at the time of CT-guided aspiration shows sclerosis, erosions and facet joint space widening at the left C5-C6 facet joint (white arrow).