RF near hardware question again...

[Timeoutofmind]

I read through some of the other threads on this and looked around elsewhere and am still a little confused.

I have a pt with a thoracic to L5 fusion.

Left sided axial pain

I was thinking it could be the left L5/S1 facet

So again, he has a pedicle screw in the L5 pedicle. Therefore, you guys are saying you do not MBB or RF at the L5 level (L4 MB) correct?

So basically I would just do a L5 DPR block to RF if successful?

Thanks in advance....

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[willabeast]

terminology can make communication difficult. pedicle screw at L5 took out the L4MB. what is left to innervate the L5S1 facet joint is
L5 DR. BTW i had a lot of patients with this problem, most of them did well after the RF of L5DR but theoretically there might be a contribution to the L5S1 facet from a branch of S1 that runs on the sacrum, i had one patient that had that extra innervation.

 

[Timeoutofmind]

terminology can make communication difficult. pedicle screw at L5 took out the L4MB. what is left to innervate the L5S1 facet joint is
L5 DR. BTW i had a lot of patients with this problem, most of them did well after the RF of L5DR but theoretically there might be a contribution to the L5S1 facet from a branch of S1 that runs on the sacrum, i had one patient that had that extra innervation.

Cool.
What I thought.
Thanks much.
Is it true 100% of the time that the pedicle screw takes out the MB? Just seems like anatomically the screw could miss it...

 

[Taus]

So basically I would just do a L5 DPR block to RF if successful?

....

Correct.

However...

I have to say that my success rate with this scenario (fused down to L5, RF of L5DR only, after >90% on dual mbb of same) has been only mediocre. Much worse my typical rf success rates on virgin backs. Suprajacent rf to fusion have seemed to fare better.

Just me or others seeing this?

Either I suck at getting L5dr or I theorize that the scar tissue I feel on the diagnostic block allows permeation of local but interferes w rf?


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[Tapspatellas]

Cool.
What I thought.
Thanks much.
Is it true 100% of the time that the pedicle screw takes out the MB? Just seems like anatomically the screw could miss it...

From what I understand the surgeons strip everything off the back of the pedicle before putting in the pedicle screw, thus the medial branch is destroyed.

 

[painfree23]

From what I understand the surgeons strip everything off the back of the pedicle before putting in the pedicle screw, thus the medial branch is destroyed.

Along the same lines , Have u run into any grounding pad issues with the type of metal used? Older fusions?

 

[Tapspatellas]

Along the same lines , Have u run into any grounding pad issues with the type of metal used? Older fusions?

I can't say that I have and I've done some adjacent segments on older fusions.

 

[bedrock]

Correct.

However...

I have to say that my success rate with this scenario (fused down to L5, RF of L5DR only, after >90% on dual mbb of same) has been only mediocre. Much worse my typical rf success rates on virgin backs. Suprajacent rf to fusion have seemed to fare better.

Just me or others seeing this?

Either I suck at getting L5dr or I theorize that the scar tissue I feel on the diagnostic block allows permeation of local but interferes w rf?


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I would say the success rate is less than virgin backs but still reasonable. I did a ton of these while in PA as I was working with a surgical group at that time. The post fusion patients % pain relief after RFA usual wasn't quite as good as their blocks, but I would say 65-70% of those patients (with strict positive dual comparative MBB before RFA) achieved at least 50% relief after L5 RFA, compared to >95% of virgin backs getting 70-80% better after RFA.

I assume you're doing your RFA with 18G cannulae and ISIS technique?

Similarly, do you perform your MBB with ISIS technique----- only injecting only 0.3ml per nerve for your MBB, doing dual comparative blocks, one with lido and one with bup, and skipping skin wheels on these patients?
(because post fusion patients are known to have a strong MBB placebo effect, because they know much miserable and unhelpful it is to have a lumbar fusion)

BTW, I don't bother with L4 MB RFA, or other MB in the levels of a PLIF, however if patient did not have a PLIF, but had only an ALIF or interspinous fusion, I would go after all MB supplying the joints I"m concerned about.

 

[Aether2000]

The surgeons strip the posterior capsule but the branches along the lateral SAP coursing superiorly over the top of the facet may remain. The pedicle screw does not necessarily remove the inflammation within or surrounding the joint, but is designed to stop the motion segment from occurring. Therefore, there remains a plausible reason for performing an RF at the level of the joint, despite the insistence of insurers to the contrary.

 

[Taus]

I would say the success rate is less than virgin backs but still reasonable. I did a ton of these while in PA as I was working with a surgical group at that time. The post fusion patients % pain relief after RFA usual wasn't quite as good as their blocks, but I would say 65-70% of those patients (with strict positive dual comparative MBB before RFA) achieved at least 50% relief after L5 RFA, compared to >95% of virgin backs getting 70-80% better after RFA.

I assume you're doing your RFA with 18G cannulae and ISIS technique?

Similarly, do you perform your MBB with ISIS technique----- only injecting only 0.3ml per nerve for your MBB, doing dual comparative blocks, one with lido and one with bup, and skipping skin wheels on these patients?
(because post fusion patients are known to have a strong MBB placebo effect, because they know much miserable and unhelpful it is to have a lumbar fusion)

BTW, I don't bother with L4 MB RFA, or other MB in the levels of a PLIF, however if patient did not have a PLIF, but had only an ALIF or interspinous fusion, I would go after all MB supplying the joints I"m concerned about.

Agree. My success rate is similar and reasonable in this setting, but I still consider it mediocre compared to virgin backs.

25g, no skin local in general....but post op backs often 22g w some skin local to get through scar.. . Usually 0.5cc.. I should probably go to 0.3...now that I use a drop of contrast I see how far that amt spreads


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[SSdoc33]

even if the medial branch is "stripped", we know it grows back in about a year.

id probably try to go intra-articular or L4 and L5 medial branch, then burn those 2 if a + block

 

[Timeoutofmind]

even if the medial branch is "stripped", we know it grows back in about a year.

id probably try to go intra-articular or L4 and L5 medial branch, then burn those 2 if a + block

Burning the L4 MB means you are right up against that pedicle screw in the L5 pedicle...I thought that was advised against due to concerns of weakening the hardware?

 

[SSdoc33]

Burning the L4 MB means you are right up against that pedicle screw in the L5 pedicle...I thought that was advised against due to concerns of weakening the hardware?

i think the titanium screw can withstand 80 degrees celsius for 90 seconds being "somewhat close" to it. can you show me literature otherwise? i think its safe

 

[willabeast]

Burning the L4 MB means you are right up against that pedicle screw in the L5 pedicle...I thought that was advised against due to concerns of weakening the hardware?

i thought the problem with being very close to hardware is that the hardware heats up.

 

[willabeast]

I would say the success rate is less than virgin backs but still reasonable. I did a ton of these while in PA as I was working with a surgical group at that time. The post fusion patients % pain relief after RFA usual wasn't quite as good as their blocks, but I would say 65-70% of those patients (with strict positive dual comparative MBB before RFA) achieved at least 50% relief after L5 RFA, compared to >95% of virgin backs getting 70-80% better after RFA.

I assume you're doing your RFA with 18G cannulae and ISIS technique?

Similarly, do you perform your MBB with ISIS technique----- only injecting only 0.3ml per nerve for your MBB, doing dual comparative blocks, one with lido and one with bup, and skipping skin wheels on these patients?
(because post fusion patients are known to have a strong MBB placebo effect, because they know much miserable and unhelpful it is to have a lumbar fusion)

BTW, I don't bother with L4 MB RFA, or other MB in the levels of a PLIF, however if patient did not have a PLIF, but had only an ALIF or interspinous fusion, I would go after all MB supplying the joints I"m concerned about.

i was thinking about this post and realized something - i have had great success with RF on fusions that extend to just above the sacrum IN SCOLIOSIS PATIENTS.
patients who had fusions for pain not nearly as good results. ! anyone else notice this? bet it would make a nice research paper.

 

[bedrock]

Possible hardware heat is one concern. Also more than half the time in a PLIF patient the fusion mass prevents true access to the MB anyway, and most of the time the nerve is toast from the surgery anyway.

For all those reasons I don't bother with MB at the fused levels of a PLIF. (But I still burned MBB at fused levels if patient had ALIF or interspinous fusion)

 

[bedrock]

i was thinking about this post and realized something - i have had great success with RF on fusions that extend to just above the sacrum IN SCOLIOSIS PATIENTS.
patients who had fusions for pain not nearly as good results. ! anyone else notice this? bet it would make a nice research paper.

I have seen the same. This is one are where 101N is partially, (partially mind you), correct because the mental state of the patient certainly makes a difference as most scoliosis fusion patients don't have psych issues, but a significant percentage of lumbar fusion patients do, and then those fusions exacerbate the underlying psych problems, so few if any medical procedures work for their back pain as so much of it is in their head.