Research Article

Modic Changes and Disc Degeneration Caused by Inoculation of Propionibacterium acnes inside Intervertebral Discs of Rabbits: A Pilot Study

Figure 3

Eight weeks after the inoculation, P. acnes-inoculated intervertebral discs showed significant disc degeneration and endplates rupture but without severe discitis. (a) The intervertebral discs harvested from the TSB-inoculated internal control segment (L4~L5) had distinct nucleus pulposus and normal arranged annulus fibrosus. (b) The segment of wild-type strain of P. acnes-inoculated intervertebral discs (L6~L7) was demonstrated as disappearance of nucleus pulposus, endplates fracture (white arrow), disorganized annulus fibrosus, and partly cartilage proliferation. (c) By contrast, the intervertebral space significantly narrowed in S. aureus-infected intervertebral discs in coincidence with total cartilage tissue replacement and disappearance of nucleus pulposus and annulus fibrosus.