Objective The rel iable animal model of intervertebral disc degeneration, can provide important experimental carrier to research pathogenesis and treatment of intervertebral disc degeneration. To establ ish three kinds of injury induced rabbit intervertebral disc degeneration models and to compare the characteristics among them by using biochemical and radiological methods. Methods Twenty-five healthy New Zealand white rabbits (weighing 2.0-2.5 kg) were randomly divided into 5 groups (n=5). The L3, 4, L4, 5 and L5, 6 discs in each rabbit were used for study. Groups A and B were forannulus puncture with an 18-gauge needle and a 22-gauge needle, respectively; group C was for nucleus aspiration; group D was for endplate injury and group E was used as a control. The lumbar spinal plain radiographs and magnetic resonance images (MRI) were evaluated, the raltive height of intervertebral disc was measured and the grades of disc degeneration were recorded 2, 4, 8, 16, and 32 weeks after operation. The water and the sulfated-glycosaminoglycan (s-GAG) contents of the nucleus were measured after sacrifice (randomly choose one rabbit from each group at each time point). Results In groups A, B, C and D, the height of intervertebral space in plain radiograph gradually decreased after operation. The anterior bony excrescences of vertebral body and varying degrees of calcification of endplate were also observed. The signal intensity of disc in T2-weighted magnetic resonance imaging decreased with time too. Compared with group E, the significant changes of height of intervertebral discs and grades of disc degeneration in MRI occurred at different time points within 4 weeks in groups A-D (P lt; 0.05). The significant change in groups C and D occured earl ier than in groups A and B. The water and s-GAG contents of discs decreased gradually in groups A-D after operation, while the significant change occurred at varying time points within 8 weeks compared with group E (P lt; 0.05). The apparent downward trend in groups C and D occured earl ier than in groups A and B. Conclusion All three methods are successful in inducing intervertebral disc degeneration. The degenerative process induced by endplate injury and nucleus aspiration is faster and more severe than that induced by annulus puncture.
ObjectiveTo investigate the morphology of endplate shape in teens with lumbar degenerative disc disease by means of MRI and the correlation between endplate shape and lumbar disc degeneration. MethodsA retrospective study was performed on 31 teenage patients with lumbar disc herniation who underwent MRI examination between January 2011 and April 2015. The morphology of endplate was classified into three groups:concave, flat and irregular based on the midsagittal T1-weighed MRI. The degree of disc degeneration was graded on T1-weighed MRI according to Pfirrmann's method with one to five points representing grade Ⅰ to Ⅴ. All endplates were determined by Modic grading system. The associations between morphology of endplate in lower lumbar spine and disc degenerative degree as well as Modic changes were evaluated retrospectively. ResultsAmong the 93 endplates, concave represented the maximum proportion (52/93). Irregular endplate increased from L3/4(4/21) to L5/S1(10/21) gradually. The average degenerative degree for concave, flat and irregular endplate was respectively (1.19±0.11) points, (2.25±0.43) points and (3.33±0.51) point, which showed significant differences (P<0.05). Irregular was the majority in protruding sections, and concave was the majority of non-protruding sections. There were 27 modic changes in 93 endplates, in which irregular was the most, showing significant difference (P<0.05), while the difference between concave and flat endplate was not significant (P>0.05). ConclusionWe can use endplate morphology, modic changes and disc degeneration to reflect degree of disc degeneration in teenage patients. Since the L5/S1 segments bear the greatest power in the lower lumbar spine, they are most prone to disc degeneration with more irregular endplates.
ObjectiveTo review the disc degeneration models and the current treatment status of calcitonin. MethodsRecent literature concerning the disc degeneration models and the calcitonin treatment of disc degeneration was extensively reviewed and summarized. ResultsDifferent models of disc degeneration have advantages and disadvantages; calcitonin can relieve disc degeneration at different degrees in vitro and in vivo studies. ConclusionDisc degeneration model for the study of disc degeneration mechanism offers a variety of ideas,and the results of calcitonin treatment in the disc degeneration model can provide the basis for future experiments.
ObjectiveTo investigate the feasibility of establishing intervertebral disc degeneration (IDD) model by using minimally invasive acupuncture and rotary-cutting. MethodsForty New Zealand white rabbits [male or female, (2.9±0.3) kg in weight] were randomly divided into control group (n=20) and experimental group (n=20). No treatment was done in the control group; percutaneous puncture was performed on L4, 5 and L5, 6 intervertebral disc by using 18G needle under C-arm X-ray monitoring for rotary-cutting of nucleus pulposus to promote degeneration of the disc in the experimental group. At 4, 8, 12, and 16 weeks after operation, general observation and MRI observation were done, and intervertebral disc degeneration was accessed based on Pfirrmann grade; the specimens were harvested for Masson staining and Safranine O staining. ResultsThe nucleus pulposus showed dark colors and reduced elasticity in the experimental group when compared with the control group. T2-weighted MRI images indicated that the disc signal intensity of control group had no obvious change at early stage, and weakened slightly at late stage; disc signal intensity of the experimental group decreased with time. According to Pfirrmann grade for disc degeneration, disc degeneration degree was significantly aggravated with time in 2 groups (P < 0.05); degeneration was significantly more severe in the experimental group than the control group at the other time points (P < 0.05) except 4 weeks (P > 0.05). Masson staining results showed that irregular arrangement of annulus with integrate structure was observed in the control group with time; the annulus of the experimental group arranged in disorder, or even disc fibrous circle rupture appeared with time. Safranin O staining showed that the nucleus pulposus cells reduced significantly in the experimental group, but did not in the control group. ConclusionMinimally invasive acupuncture and rotary-cutting could successfully establish the IDD model in rabbits.