Muscle atrophy in ankylosing spondylitis: CT demonstration

Area of Science:

• Radiology
• Orthopedics
• Rheumatology

Background:

• Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the spine.
• Spinal and hip joint involvement are common in advanced AS.
• Muscle atrophy is a potential complication, but its direct correlation with spinal and hip pathology in AS requires further elucidation.

Observation:

• Computed tomography (CT) revealed severe atrophy of posterior spinal muscles and the left psoas muscle.
• The patient had chronic ankylosing spondylitis with gross total ankylosis of the thoracic and lumbar spine.
• Severe unilateral left hip joint involvement was also noted.

Findings:

• A strong correlation was observed between extensive spinal ankylosis and significant muscle wasting.
• Reduced mobility in the spine and left hip joint appeared to contribute to the observed muscle atrophy.
• The psoas muscle, crucial for hip flexion, showed marked atrophy.

Implications:

• This case highlights the potential for profound muscle atrophy in chronic ankylosing spondylitis.
• Findings suggest that spinal fixation and joint immobility are key drivers of muscle loss in AS.
• Understanding this relationship can inform therapeutic strategies aimed at preserving muscle mass and function in AS patients.