Caudal Agenesis: Classification Based on the Pathoembryogenesis of the Spinal Cord

Area of Science:

• Pediatric Surgery
• Neurology
• Developmental Biology

Background:

• Caudal agenesis (CA) is a congenital anomaly involving defects in lower vertebrae.
• Existing classifications of CA focus on bony defects or conus medullaris levels.
• A novel pathoembryogenic classification is proposed, considering conus shape and filum.

Purpose of the Study:

• To develop and validate a new pathoembryogenic classification for caudal agenesis.
• To assess the accuracy of this new classification in predicting neurological status.
• To determine its efficacy in identifying patients requiring spinal untethering.

Main Methods:

• Retrospective review of 89 patients with CA (1985-2019).
• Categorization into three groups: failure of formation, failure of regression, and normal, based on conus level, shape, and filum.
• Comparison of the pathoembryogenic classification with bony defect and conus level classifications.

Main Results:

• The pathoembryogenic classification showed significant differences in motor/sensory deficits (42% vs. 16% vs. 0%, P=.039).
• It was a significant predictor of motor deficits (OR 11.66, P=.007) and suggestive for sensory deficits (OR 5.44, P=.066).
• This classification significantly differentiated the need for untethering (42% vs. 81% vs. 12%, P<.001).

Conclusions:

• Traditional bony classifications may overestimate the correlation with spinal cord abnormalities.
• The new pathoembryogenic classification is valuable for prognosing neurological status in CA.
• It effectively identifies patients who are more likely to require spinal untethering surgery.