The measurement of normal lumbar intervertebral discs and its significance

Objective Relevant parameters of normal lumbar intervertebral discs were measured, in order to provide basic data for designing artificial lumbar disc and artificial prosthetic nucleus that are suitable for Chinese as well as offer data of normal disc height as reference for clinical diagnosis of disc height loss.Methods MRI data of normal lumbar vertebrae of 300 Chinese adults(including 136 males and 164 females)who complained of low back pain were collected. The anterior height, the middle height, the posterior height and the intervertebral angle in segment L1/2~L5/S1, the sagittal and transverse diameter of disc, the sagittal and transverse diameter of nucleus pulposus in segment L2/3~L5/S1 were measured. Results No significance was detected in age(P0.05). Significance was detected in gender(P0.05) and data got from male was higher than that from female mostly. Significance was detected in segment(P0.05). The anterior height and intervertebral angle increased with the increment of the segment number. The middle height, the posterior height, the sagittal and transverse diameter of disc, the sagittal and transverse diameter of nucleus pulposus increased with the increment of the segment number except for segment L5/S1. In each segment, There were linear relationships between the sagittal and transverse diameter of disc, with the same case in the sagittal and transverse diameter of nucleus pulposus. Conclusions Measurement of disc height is valuable to the diagnosis of lumbar spine disease. In the design of artificial lumbar disc and artificial prosthetic nucleus, gender and segmental difference should be considered. The linear relationship between the sagittal and transverse diameter of disc and nucleus pulposus should also be taken into account.