Brucella Spondylitis¶

Definition¶

Brucella spondylitis is spinal infection caused by Brucella species (B. melitensis, B. abortus, B. suis). It is endemic in the Mediterranean, Middle East, Latin America, and parts of Asia, and is contracted through contact with infected livestock or consumption of unpasteurized dairy products. The lumbar spine is most commonly affected.

Imaging Findings¶

MRI¶

Vertebral body — Low T1, high T2 signal in the vertebral body, often centered at the anterior endplate
Disc involvement — Usually present, similar to pyogenic spondylodiscitis
Endplate changes — Erosion and irregularity, but often less destructive than pyogenic infection
Paravertebral abscess — Smaller than TB, usually well-defined
Epidural extension — Less common than pyogenic infection but can occur
Enhancement — Disc and endplate enhancement on post-contrast images

CT¶

Endplate sclerosis and erosion (may show a mixed lytic-sclerotic pattern)
"Pedro Pons" sign — Gas within the disc (rare but suggestive)
Small paravertebral soft tissue component

Key Distinguishing Features¶

Often presents with prominent endplate sclerosis — more than typical pyogenic infection
Less aggressive bone destruction than pyogenic or TB infection
May show a "scalloped" anterior vertebral body contour
Clinical context is critical — travel history, occupational exposure, positive Brucella serology

Clinical Pearl

Brucella spondylitis can mimic degenerative Modic changes on MRI because it often produces endplate sclerosis with relatively mild disc and vertebral body changes. The clinical triad of endemic exposure + back pain + positive Brucella serology should prompt consideration of this diagnosis. The "Pedro Pons" sign (intradiscal gas) is rare but characteristic.

Management¶

Antibiotics — Prolonged combination therapy (doxycycline + streptomycin or rifampin for 3–6 months)
Surgery — Rarely needed; reserved for neurological deficit or spinal instability

Key Points¶

Endemic in Mediterranean, Middle East, and Latin America
Lumbar spine is most commonly affected
Endplate sclerosis is more prominent than in pyogenic infection
Less destructive than pyogenic or TB spondylitis
Clinical context and serology are essential for diagnosis
Prolonged combination antibiotic therapy is the standard treatment

References¶

Brucella spondylodiscitis. Radiopaedia.org. https://radiopaedia.org/cases/brucella-spondylodiscitis
Hayoun MA, Muco E, Shorman M. Brucellosis. In: StatPearls. Treasure Island (FL): StatPearls Publishing; updated 2023 Apr 29. https://www.ncbi.nlm.nih.gov/books/NBK441831/
Al-Shahed MS, Sharif HS, Haddad MC, Aabed MY, Sammak BM, Mutairi MA. Imaging features of musculoskeletal brucellosis. RadioGraphics. 1994;14(2):333-48. https://pubmed.ncbi.nlm.nih.gov/8190957/
Sharif HS, Aideyan OA, Clark DC, Madkour MM, Aabed MY, Mattsson TA, et al. Brucellar and tuberculous spondylitis: comparative imaging features. Radiology. 1989;171(2):419-25. https://pubmed.ncbi.nlm.nih.gov/2704806/
Chelli Bouaziz M, Ladeb MF, Chakroun M, Chaabane S. Spinal brucellosis: a review. Skeletal Radiol. 2008;37(9):785-90. https://pubmed.ncbi.nlm.nih.gov/17962938/
Gou L, Yang Y, Li J, et al. MRI findings and classification of brucella spondylitis: a China multicenter study. Eur J Med Res. 2024;29(1):469. https://pmc.ncbi.nlm.nih.gov/articles/PMC11438224/
Expert Panel on Neurological Imaging; Ortiz AO, Levitt A, Shah LM, Parsons MS, et al. ACR Appropriateness Criteria® Suspected Spine Infection. J Am Coll Radiol. 2021;18(11S):S488-S501. https://pubmed.ncbi.nlm.nih.gov/34794603/