Experimental Investigation of the Secondary Changes in Imaging After Lumbar Disc Nucleoplasty in Rabbits.

AIM

To explore the changes in imaging after lumbar disc nucleoplasty in rabbits.

MATERIAL AND METHODS

Twenty-four rabbits were randomly selected for X-ray, computerized tomography (CT), and magnetic resonance imaging (MRI) at 2, 6, and 12 weeks post operation. Moreover, their L3/4, L4/5, and L5/6 intervertebral discs were randomly selected as the untreated, annulus puncture, and nucleoplasty groups, respectively. Changes in disc height index (DHI%) and MRI grade were measured and compared. CT three-dimensional reconstruction was used to evaluate adjacent bone endplate changes.

RESULTS

The untreated group's DHI% decreased slightly at different time points (p > 0.05), while that of the nucleoplasty and annulus puncture groups decreased progressively (p < 0.05). At six weeks post operation, the nucleoplasty group's DHI% was significantly lower than that of the annulus puncture group (p < 0.05), with mild osteosclerosis and local rough changes in the endplate. At 12 weeks post operation, a "bone bridge" connection was observed in the nucleoplasty group. There was no significant difference in MRI grade between the untreated and annulus puncture groups at different time points (p > 0.05). MRI grades of the intervertebral disc in the nucleoplasty and annulus puncture groups showed a progressive increase (p < 0.05). Compared with the annulus puncture at the same time point, the nucleoplasty group's MRI grade of the intervertebral disc was significantly higher (p < 0.05). Thus, damage caused by an annulus puncture can lead to progressive degeneration of the lumbar disc.

CONCLUSION

Nucleoplasty may have a cumulative effect with the injury of the annulus puncture. Clinicians need to comprehensively consider advantages and disadvantages of nucleoplasty, strictly grasp indications of treatment, and prevent longterm complications.