The bone bridge significantly affects the decrease in bone mineral density measured with quantitative computed...

Area of Science:

• Orthopedics
• Rheumatology
• Radiology

Background:

• Ankylosing spondylitis (AS) is characterized by spinal bone fusion.
• Spinal inflammation is a presumed cause of reduced bone mineral density (BMD) in AS.
• Immobilization is a known risk factor for BMD reduction.

Purpose of the Study:

• To investigate the relationship between spinal immobilization due to syndesmophytes and BMD reduction in AS patients.
• To determine if bone bridge formation correlates with decreased BMD in the lumbar spine.

Main Methods:

• Retrospective analysis of 47 male AS patients diagnosed via modified New York criteria.
• Correlation analysis between radiographic bone bridge presence and quantitative computed tomography (QCT)-measured BMD in the lumbar spine (L1-L4).
• Assessment of bone bridge score and Bath Ankylosing Spondylitis Radiology Index (BASRI) spinal mobility scores.

Main Results:

• 63.8% of patients had osteopenia or osteoporosis.
• Bone bridge formation negatively correlated with lumbar BMD (p < 0.05).
• Increased bone bridge scores correlated with reduced spinal mobility (BASMI flexion), and decreased BMD correlated with reduced spinal mobility (p < 0.05).

Conclusions:

• Vertebral immobilization from bone bridge formation contributes to decreased BMD in ankylosing spondylitis.
• Reduced spinal mobility is linked to both bone bridge formation and lower BMD in AS.