BACKGROUND:Changes in the parameters of lumbar spine bone structure are direct reaction of morphological changes in lower lumbar spine bone structure. These changes possibly result from normal structure strain of the spine affected by long-term external or internal factors. Whether the conditions reflected by different parameters are identical, and whether corresponding clinical symptoms are correlative stil deserves further exploration. OBJECTIVE:To measure and compare the construction parameters of lumbar spine bone structure in lower lumbar disc herniation patients, and to investigate whether abnormalities of lumbar bony structure could lead to lower lumbar disc herniation and to evaluate the significance in degenerative lumbar disc. METHODS:From March 2008 to March 2010, 207 cases of lower lumbar disc herniation were randomly selected from the Department of Orthopedics, First Affiliated Hospital, Fuzhou General Hospital, Nanjing Military Area Command of Chinese PLA. They received CT examination at the Department of Radiology at the same period, and results revealed that 143 cases of lower lumbar disc non-herniation served as control group. According to gender, they were divided into male and female groups. According to ages, they were divided into 25-34 group, 35-44 group, 45-54 group and 55-65 group. They were studied by measuring spinous process deflection angle, facet joint angle, lumbar vertebrae curvature, angle of lumbar vertebrae curvature, lumbosacral angle. RESULTS AND CONCLUSION:Process deflection angle at L 4 and L 5 levels had a significant statistical difference between the lower lumbar disc herniation group and the control group. The date did not show normal distribution. Using Rank sum test, it had a significant statistical difference (Z=-10.609,-12.074, P<0.01). There was not significant statistical difference between the lower lumbar disc herniation group and the control group on the facet asymmetry, lumbar vertebrae curvature, angle of lumbar vertebrae curvature and lumbosacral angle at various ages (P>0.05). There only was significant difference on lumbosacral angle between male group and female group (P=0.007<0.01). There was significant difference on the facet asymmetry, lumbar vertebrae curvature, angle of lumbar vertebrae curvature and lumbosacral angle between 55-65 age group and 25-34 age group or 35-44 age group (P<0.01), and there was significant difference between 45-54 age group and 25-34 age group (P<0.01). These data suggested that the abnormalities of lumbar bony structure could not directly lead to the lumbar disc herniation, but the abnormalities of lumbar bony structure aggravate the lumbar intervertebral disc degeneration.

BACKGROUND: Resection of the nudeus pulposus is the classical treatment for intervertebral disc protrusion, except a higher recurrence rate. OBJECTIVE: To verify the feasibility of establishing an animal model of intervertebral disc degeneration by puncture and aspiration via a posterolateral approach to simulate resection of human nucleus pulposus. DESIGN, TIME AND SE'I'FING: The experiment was conducted in the animal Experimental Center of Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from October 2006 to February 2007. MATERIALS: Twenty Japanese big ear rabbits were selected to establish animal models of intervertebral disc degeneration. METHODS: Some nucleus pulposus tissues were abstracted from the L1-2 and L3-4 segment of 20 rabbits by the puncture and aspiration method using a 21-gaege hypodermic needle. Histological analysis was performed at 2, 4, 8, 12 weeks after surgery, and L2-3 segment was used as control group.MAIN OUTCOME MEASURE: Histological structure of the intervertebral disc was observed by homatoxylin-eosin staining. RESULTS: Hematoxylin-eosin staining revealed a great deal of complete nudeus pulposus tissues, clear boundaries between nucleus pulposus and annulus fibrosus in the control group, and the structure of near normal annulus fibrosus was almost normal, nucleus pulposus tissue had a large number of nucleus pulposus cells. In the experimental group, the nucleus pulposus cell reduced in amount in the fourth week, the nucleus pulposus at the twelfth week were mainly full of flbroblests, while few nucleus pulposus cells were found.CONCLUSION: It is successful to establishing an animal model of intervertebral disc degeneration by puncture and aspiration via a posterolateral approach based on simulating the resection of human nucleus pulposus. This model is available for repairing intervertebrai disc degeneration using tissue engineering techniques.

BACKGROUND:It remains unclear what kind of changes in imaging and histopathology would appear in intervertebral disc after removal of nucleus pulposus over time.
OBJECTIVE:To observe the alteration in imaging and histopathology of rabbit lumbar intervertebral disc after nucleus pulposus aspiration.
METHODS:A total of 32 Japanese rabbits were subjected to nucleus pulposus aspiration in posterior lateral L 3/4 intervertebral disc with a 21-gauge hypodermic needle. L 2/3 intervertebral disc served as a normal control. At 2, 4, 8 and 12 weeks after aspiration, eight rabbits according to grouping received radiograph in the lateral position of lumbar vertebra. The height of L 3/4 and L 2/3 intervertebral space was measured and intervertebral disc height index was calculated. Rabbits received median sagittal MRI examination and histopathological examination of intervertebral disc.
RESULTS AND CONCLUSION:The intervertebral disc height degraded slowly at 2, 4, 8, and 12 weeks after aspiration. However, the difference between 8 and 12 weeks was reduced. Compared with normal control, intervertebral disc height index significantly reduced at various time points (P<0.05). The nucleus pulposus signal intensity was gradual y reduced at 2, 4, 8, and 12 weeks after aspiration, and reached grade 4 of modified Thompson grading criteria at 8 weeks. After aspiration, gelatinous nucleus pulposus of disc slowly exhibited fissures with time, morphous was slowly disordered and showed significant fibrosis performance at 12 weeks. In nucleus pulposus region, more cartilage-like cells were found at 4 weeks after operation. The cells were active. Nucleus pulposus cells decreased significantly. At 8 and 12 weeks after operation, fibroblasts increased in nucleus pulposus region, and the number of cartilage-like cells reduced. The annulus fibrosus gradual y became distorted, disordered, with processes and layers, and fiber breakage appeared. These results indicated that after puncturing lateral annulus fibrosus and aspirating the nucleus pulposus, radiograph height of the intervertebral disc and MRI T2-weighted signal intensity gradual y reduced. Pathological changes were observed. However, the degeneration al eviated between 8-12 weeks.