This experimental study hypothesize that “rapid degeneration of the intervertebral disc over the ability of auto-stabilization by osteophytes bridging to adjacent segments might be the pathomechanism of degenerative lumbar scoliosis (DLS).” An effort to prove this hypothesis was attempted by confirming the differences in the expression of matrix metalloproteinase-3 (MMP-3) in DLS and pure spinal stenosis.

The intervertebral disc materials obtained during a discectomy through a posterior approach, were included in this experimental study. Two protruded herniated nucleus pulposus were included for the control group. Eight spinal stenosis and seven DLS were included as experimental groups 1 and 2, respectively. The expression of MMP-3 was evaluated by immunohistochemical staining and western blotting using anti human MMP-3 antibody.

In the immunohistochemical stains, sparse staining was noted in the control group. More staining, however, mainly extracelluar, was noted in the discs of DLS compared with those of the spinal stenosis group. In western blotting, greater MMP-3 expression was noted in the discs of DLS (mean optical density: 20.68) than in those of the spinal stenosis group (mean optical density: 6.24) which was statistically significant (p<0.05).

Rapid degeneration of the intervertebral disc might be an important factor for the pathogenesis of DLS. MMP-3 could be one of the key enzymes for the rapid degeneration of the intervertebral discs especially in DLS.