[ESTABLISHMENT OF INTERVERTEBRAL DISC DEGENERATION OF RABBITS BY USING MINIMALLY INVASIVE ACUPUNCTURE AND ROTARY-CUTTING].

OBJECTIVE

To investigate the feasibility of establishing intervertebral disc degeneration (IDD) model by using minimally invasive acupuncture and rotary-cutting.

METHODS

Forty 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.

RESULTS

The 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.

CONCLUSION

Minimally invasive acupuncture and rotary-cutting could successfully establish the IDD model in rabbits.