A lumbar disc degeneration model established through an external compressive device for the study of microcirculation changes in bony endplates

Objective: To establish a new animal model of intervertebral disc degeneration (IDD) by axial compression on lumbar spine of rabbits and to investigate the changes of microcirculation in bony endplates during the progress of IDD. Methods: 32 New Zealand white rabbits were equally divided into 4 groups as follows: Control group with no operation and compression, Sham operation group with apparatus placement only, 2-week compression group and 4-week compression group with the devices installed and compressed for their preset duration. All groups of rabbits underwent MRI, histological evaluation, disc height index measurement and Microfil contrast agent perfusions to examine the ratio of endplate microvascular channels. Results: The new animal model of IDD was successfully established after axial compression for 4 weeks. The MRI grades for the 4-week compression group was 4.63 ± 0.52 and significantly different to the sham operation group (P