I have spinal stenosis at L4 L5. One year back,
1) since the disc herniation is at L4 L5, why does the injection at L5 S1 help my sciatica?
2) If I go for spinal laminotomy or some thing like that, do they drill through the vertebrae? Does that cause future weakness in the spine. What is the percentage chance of that happening?
Multiple levels involved, laminotomy does not cause any weakness.
Hello again in the "Ask a Doctor" service.
I have read your new question and here is my explanation.
Since the injection at the L5-S1 level helped improved you significantly and the herniation is at the L4-L5 level, it means that other spine issues such spondylosis, multilevel degenerative changes, are causing your symptoms besides the herniation.
These degenerative changes may irritate the nerve roots above and below the level of the herniation significantly.
When we perform laminotomy, we remove a small portion of lamina and ligaments leaving the natural support of the lamina in place, avoiding this way in maximum any instability.
So, the percentage of the weakness of the spine after laminotomy is minimal.
Laminectomy in the other hand removes all the lamina and may cause some degree of instability.
Hope you found the answer helpful.
Let me know if I can assist you further.
1) You mentioned above and below the level of herniation may be involved. My herniation is at L4 L5. Injection at L5 S1 helped. Next injection should I include L3 L4 also in addition to L5 S1.
2) I understand that epidural injection do not penetrate any bone. Is that correct? Do they normally cause any other physical damage which can weaken the spine.
3)How will the doctor select between laminotomy and laminectomy?
1) There is no need to include the L3-L4 level for injection if there are no symptoms related to it. The injection is done only after strong evidence ( clinical and radiological ) that this level is responsible for symptoms.
2)No, injection does not penetrate any bone and does not cause any spine weakness.
3) There are a number of factors that lead to the choice of laminotomy or laminectomy. These include the location of the stenosis (laminotomy is done mainly in cases of stenosis in one part of the lamina), clinical and radiological correlation, the experience of the surgeon, etc.
Hope this helps.