Abstract
The nerve supply to the posterior longitudinal ligament (PLL), intervertebral disc (IVD) and their attachment to the vertebral body (enthesis) of the lumbar spine was investigated by AchE enzymehistochemistry.
In the vertebral portion of the PLL, there was a nerve network supplied by the sinu-vertebral nerve. In the deep layer of the intervertebral portion (enthesoperidiscal region), there was a dense nerve plexus supplied through other roots. Nerve fibers and terminals were found only in the PLL and the superficial layer of the annulus fibrosus. In the nerve plexus of the enthesoperidiscal region, nerve terminals were small in number in comparison with abundant nerve fibers, but many free endings were found in the enthesis. The clinical implications of this fact show in the frequent occurrence of enthesopathy.
The density of the nerve plexus in the intervertebral portion of the PLL was different according to the level of the spine. This is much related to the extensibility of the PLL.
Experimental study revealed that these nerve fibers and terminals are derived mostly from the dorsal roots of the spinal nerves, and that the vertebral portion of the PLL is supplied bilaterally and polysegmentally, and the intervertebral portion, bilaterally and unisegmentally.
These results suggest that the abundant nerve fibers are related not only to the regulation of movement and posture of the spine through perceptive action, but also to the local circulation, metabolism and the occurrence of inflammation, especially in the enthesis.
