When discs re-herniate, does the jelly tend to spill out in the same direction it did previously?
If the first herniation resulted in lateral recess stenosis, would subsequent herniations be likely to spill out the other side or CENTRALLY?
Of course, I am most interested in the T-spine. Due to the nature of the disc material, the mass effect of a stenotic lesion would lessen over time…no?
I would think the mechanism of injury would be relevant. But how relevant? Is it really as simple as squeezing one side of the jelly donut and seeing the jelly come out the other? I realize the scar is weaker than the original ligamentous material. However, is there a general tendency as far as re-herniations go? In your experience, can you identify the relevant factors determining direction of re-herniation.
PS. A while back I read a couple of series where the researchers suggested that material that appeared calcified and presumed hard on CT and/or MRI was soft on dissection. This is intriguing. (I can dig this up if necessary.)
Recurrent herniations tend to follow the same pathway as the initial herniations although if surgery has previously been performed, the scar can lead the fragment down a different tract. None the less, the herniation will typically be on the same side.
A disc herniation that is nuclear material will typically dehydrate over time if wedged into the canal. This dehydration will reduce the mass effect and lessen the compression. If however, the herniation material is cartilaginous endplate material, this material will not dehydrate over time and will cause significant compression of the nerve or cord.
Reherniations occur with typical BLT activity in the lumbar spine (bend, twist, lift at the same time). In the thoracic spine, the recurrence mechanism is not as well known.