Radiologists and orthopedists don't always use the same terminology for disc lesions, which often causes confusion, particularly with workers' compensation and personal injury cases. As a normal disc is subjected to torsion insult, circumferential tears occur in the intact annulus. These tend to accumulate centrally and form radial fissures into which nuclear disc material may protrude. As the disc expands, it produces pain initially by stimulating the sensory nerve fibers in the annulus, posterior longitudinal ligament and the neurovascular capsule of the disc.
Resultant pain is typical of a lumbar dorsal ramus syndrome.
Continued herniation may then produce compression of the mixed spinal nerve, identified by true radicular pain radiating to the extremity, as well as motor, sensory and reflex deficit. Accumulating evidence suggests that the most significant pain generator is the dorsal root ganglia rather than the preganglionic or postganglionic segment of the spinal nerve. The differentiation of a contained from a noncontained disc herniation is an important distinction because of the therapeutic implications inherent in the differential diagnosis. Contained disc herniations generally will respond well to conservative care, while uncontained disc herniations may not. However, I would say that more and more orthopedists are recommending conservative care for even the uncontained discs.