This document compares and contrasts the radiographic findings of multiple myeloma, tuberculous spondylitis, and pyogenic spondylitis. Multiple myeloma lesions are sharply defined, small lytic bone lesions. Tuberculous spondylitis spreads beneath the anterior longitudinal ligament, often involving multiple levels while sparing the posterior elements. Pyogenic spondylitis is characterized by early narrowing of the disc space due to proteolytic enzyme destruction. Later stages of both tuberculous and pyogenic spondylitis can result in vertebral body collapse, sclerosis, or fusion.

1. Multiple Myeloma Tuberculous spondylitis Pyogenic spondylitis
• Myeloma lesions are sharply
defined
• small lytic areas (average size
20 mm) of bone destruction with
no reactive bone formation
• Although myeloma arises within
the medulla, disease progression
may produce infiltration of the
cortex, invasion of the
periosteum and large
extraosseous soft tissue masses.
• The pattern of destruction may
be geographic, moth eaten or
permeated.
• Pathological fractures are
common.
• The spread of infection is typically described as 'subligamentous':
beneath the anterior longitudinal ligament, usually sparing the
posterior elements and often involving multiple levels.
• may vary depending on the pathologic type and chronicity of the
infection. In early tuberous spondylitis, the disc space is preserved
more than pyogenic spondylitis from the lack of proteolytic enzyme.
• A reduction in vertebral height is often seen with the irregularity of
the anterosuperior endplate
• Due to the subligamentous extension, there may be some irregularity
of the anterior vertebral margin. This is a classical appearance with TB
spondylitis.
• Later, paraspinal collections can develop which can be remarkably
large.
• Ivory vertebrae can result in re-ossification.
• Lytic destruction of anterior portion of vertebral body
• Increased anterior wedging
• Collapse of vertebral body
• Reactive sclerosis on a progressive lytic process
• Enlarged psoas shadow with or without calcification
• Additional radiographic findings may include the following:
• Vertebral end plates are osteoporotic.
• Intervertebral disks may be shrunk or destroyed.
• Vertebral bodies show variable degrees of destruction.
• Fusiform paravertebral shadows suggest abscess formation.
• The earliest and most common
radiographic finding is narrowing
of the disc space in pyogenic
spondylitis.
• It is due to the disc destruction
by proteolytic enzyme and is
followed by irregularity of
endplate from the bone
destruction.
• In progression and healing of the
disease, osteolytic changes are
followed by new bone formation
and osteosclerotic changes at
the vertebral margins
• In the chronic period (>10 wk),
vertebral body sclerosis or
collapse may be observed on
either side of a narrowed disk
space. Paraspinal soft-tissue
opacity may develop. Gradual
disk obliteration may occur with
fusion (ie, osseous, fibrous).
Partial restoration of disk height
may be observed with successful
treatment.

2. MRI findings of pyogenic and tuberculous spondylitis

3. Multiple Myeoloma - Xray