Which vertebral body region is most commonly affected in Pott disease of the spine?

Explanation

## Anatomical Pattern of Pott Disease **Key Point:** Pott disease characteristically affects the anterior vertebral bodies and spreads to the adjacent intervertebral disc, distinguishing it from other spinal infections. ### Pathological Progression 1. **Initial site:** Anterior metaphyseal region of vertebral body (rich vascular supply) 2. **Spread pattern:** Longitudinally along anterior vertebral bodies; crosses disc space early (unlike pyogenic spondylodiscitis) 3. **Vertebral involvement:** Typically affects two or more adjacent vertebrae 4. **Disc involvement:** Early and extensive, often before significant vertebral collapse ### Why Anterior Vertebral Body? The anterior vertebral body has a rich anastomotic vascular network that facilitates hematogenous seeding of *Mycobacterium tuberculosis*. The organism thrives in the hypoxic, caseous environment of the metaphysis. **Clinical Pearl:** The classic "kyphotic deformity" (gibbus) results from anterior vertebral body collapse, not posterior element involvement. This distinguishes Pott disease from other spinal pathologies. **High-Yield:** In contrast to pyogenic spondylodiscitis (which typically spares the disc initially), TB crosses the disc space early because the organism produces proteolytic enzymes and spreads via the rich vascular plexus. [cite:Robbins 10e Ch 8]