Abstract
It is considered that quantitative evaluation of a variance of intradiscal pressure during spinal movement could be an important finding to describe the segmental disorders. Five functional spinal units from porcine lumbar vertebra were studied using the testing apparatus designed to simulate spinal side bending. NZ (Neutral Zone) calculated from a moment-angle curve observed insignificant increase after supraspinal and interspinous ligament desmotomy and after unilateral facetectomy while significant increase after bilateral facetectomy. Intradiscal pressure under maximum bending increased 15% after posterior longitudinal ligament desmotomy.
