Anatomic radiological variations in developmental lumbar spinal stenosis: a prospective, control-matched comparative...

Area of Science:

• Radiology
• Orthopedic Surgery
• Spinal Anatomy

Background:

• Developmental lumbar spinal stenosis is a congenital malformation of the dorsal spine.
• Characterized by short pedicles and a trefoil canal, it predisposes individuals to early neural compression.

Purpose of the Study:

• To radiographically identify and characterize the anatomical variations in dorsal spinal elements associated with developmental lumbar spinal stenosis.
• To differentiate these variations from other causes of spinal stenosis.

Main Methods:

• Prospective, control-matched comparative analysis of 66 patients with developmental lumbar spinal stenosis and 45 controls.
• Utilized magnetic resonance imaging (MRI) and anteroposterior (AP) plain radiographs.
• Assessed spinal canal cross-sectional area (CSA), thecal sac dimensions, interpedicular distance, interlaminar angle, and disc degeneration, all relative to vertebral body diameter (VBD).

Main Results:

• Patients with stenosis showed significantly reduced spinal canal CSA-to-VBD ratios, AP canal diameter-to-VBD ratios, and interpedicular distance-to-VBD ratios across most lumbar levels.
• Reduced interlaminar angles and transverse canal diameter-to-VBD ratios were also observed, except at L1.
• No significant difference in disc degeneration incidence or thecal sac CSA-to-spinal canal CSA ratios was found between groups, except at L3 and S1.

Conclusions:

• Identified three distinct spinal canal morphologies in developmental lumbar spinal stenosis: flattened canal (reduced AP diameter), narrow canal (reduced interlaminar angle), and globally reduced canal parameters.
• Early presentation and subtle spondylosis are common but not definitive diagnostic features.