We obtained intervertebral discs with cartilage endplates and underlying cancellous bone at operation from patients with degenerative disc disease and then used immunohistochemical techniques to localise the nerves and nerve endings in the specimens. We used antibodies for the ubiquitous neuronal protein gene product 9.5 (PGP 9.5). Immunoreactivity to neuropeptide Y was used to identify autonomic nerves and calcitonin gene-related peptide (CGRP) and substance P to identify sensory nerves. Blood vessels were identified by immunoreactivity with platelet-endothelial cell-adhesion molecule (CD31; PECAM). In a control group with no known history of
In a study on ten fresh human cadavers we examined the change in the height of the intervertebral disc space, the angle of lordosis and the geometry of the facet joints after insertion of intervertebral total disc replacements. SB III Charité prostheses were inserted at L3-4, L4-5, and L5-S1. The changes studied were measured using computer navigation sofware applied to CT scans before and after instrumentation. After disc replacement the mean lumbar disc height was doubled (p <
0.001). The mean angle of lordosis and the facet joint space increased by a statistically significant extent (p <
0.005 and p = 0.006, respectively). By contrast, the mean facet joint overlap was significantly reduced (p <
0.001). Our study indicates that the increase in the intervertebral disc height after disc replacement changes the geometry at the facet joints. This may have clinical relevance.