Genicular RFA. Any input helpful!

[thecentral09]

hey all, I’m doing a significant amount genicular RFA with mixed results. Mainly in patients who are non-surgical candidate with severe knee osteoarthritis, morbid obesity etc. I work in the hospital when I started they already had coolief so I have been using that exclusively. Used it in fellowship. based on the Franco cadaver study, the superior medial and superior lateral Lie in the 50th to 75th percent depth of the distal femur, So I do two lesions at the sites (even with cooled), one with the tip at the 70th percent, and one at the 50th% . One lesion at the 50th percentile inferomedial site . I wish my outcomes were better, any suggestions are appreciated . Most recent procedure pictures posted here.
I have interest in utilizing ultrasound, but would ask how you are all doing it? Finding the artery that runs with the target nerve and placing the RFA probe next to the artery that runs with the targeted nerve and placing RFA probe adjacent to it?

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[pastafan]

Needle positions look too proximal.

 

[Orin]

I have not jumped to always using ultrasound for RF although I do try it from time to time. I find myself chasing the nerves more using sensory stimulation, otherwise it's basically just using ultrasound to see what I can easily visualize with fluoroscopy.

I do 3 of the 4 per the Coolief protocol, as the femoral branch is normally not a complaint for most, but I add it on when it is. I do think your locations shown are a bit too proximal on the femur and I'm not crazy about the depth of them on the lateral image as I normally recommend a little deeper, but we're splitting hairs.

Step 1 is to get the most amazing fluoroscopic imaging possible, with the joint space as opened up as you can and the midline truely found using tilt/oblique. That generally puts you at a very weird look to most, but is critical if you're going to use fluoro-based landmarks for this burn.
Step 2 is to find the right spot, which you can argue about or read about or whatever makes you happy.
Step 3 is to verify again before you burn that the cannula haven't moved before you burn, with that most amazing view from Step 1.

I generally find with trainees that they rush through step one, and then even though it looks like the right spot on step 2, they're not close when we get the views properly aligned for step 3. Cooled RF is forgiving, but it also isn't magic.

The other thing I find is people are doing better with RF when I've cut down to 0.5 - 1 mL of injectate on the diagnostic blocks, so you may be having some false positives that should not have gotten RF.

 

[lobelsteve]

Needle positions look too proximal.

By almost an inch.

 

[jewwithguitar]

I agree with the above, needles are placed too proximal and anterior.

Orin, would you mind posting an image of the fluoro view you described in Step 1 and explain any tips you use to obtain said view?

 

[pastafan]

Not Orin but:

 

[Sadder]

Not Orin but:

Do u us bipolar RFA genicular? If yes may be picture?

 

[Orin]

I don't enjoy posting images from my PACS, but using the internet, my big points are generally these simple things that people hounded me on during training

Most of us do these with one leg bent and the other flat so we can shoot across. That's great and all but the patient's don't always put their knee in the ideal location, and the fluoro techs may not get a perfect view. In that initial view I like to open up the joint space as much as possible and get the plateau's flat ideally. I'm generally plus/minus on the patella being in the midline, as I often find it is pulled into a weird position in some of my patients, so I focus more on the intercondylar eminence being midline-ish and the condyle borders being sharp.

This is for a tunnel view of the knee but it captures what I'm trying to achieve, without the same purpose necessarily. It does often put the patella over one of my superior target sites, so I end up coming a bit more oblique with the cooled RF probes or in a slightly superior to inferior angulation with a conventional.

Then on the lateral, the big thing I see is folks not lining up the lateral/medial condyles. If you see both lines, then you need to keep obliquing or internally/externally rotating the knee, as otherwise your halfway depth is off.

If you're doing fluoro based RF, I do think it's important that the fluoro based landmarks are precise, both at the initial placement and then right before the burn, because patients move a lot during this procedure.

knee - Startradiology
X-knee - Startradiology

 

[pastafan]

Do u us bipolar RFA genicular? If yes may be picture?

Unipolar. 1 lesion 80 C for 2 minutes

 

[jewwithguitar]

Thanks Orin! Very detailed and helpful.

 

[myrandom2003]

Are you guys doing stimulation before you burn? sensory or both?

 

[lobelsteve]

Are you guys doing stimulation before you burn? sensory or both?

Used to do motor, now I just lesion.

 

[myrandom2003]

Can you guys throw up some actual fluoro pics?

I get some weird knees lately where there is almost no groove and it just kind of takes a very shallow take off from the femur kind of high up.

Also I have never been able to get that tunnel view posted by orin. Is that just me?

 

[Orin]

Can you guys throw up some actual fluoro pics?

I get some weird knees lately where there is almost no groove and it just kind of takes a very shallow take off from the femur kind of high up.

Also I have never been able to get that tunnel view posted by orin. Is that just me?

Lets take a step back then. How are you positioning the patient? Are both knees straight?

Some folks suck and you get what you can get, so this is my initial shot. I didn't do a good job saving many pics because I was working with a new fluoro tech, but you can see where I'm marking a target point for a quick set of genic blocks. The blobs there are fat rolls because I seem to be mandating your BMI has to be greater than your age for injections right now.

I could've obliqued or tilted a touch more caudal, but for the block that's good enough.
I suspect you're not putting much bend under the knee, and likely not tilting far enough caudally as it's a very weird angle.

 

[myrandom2003]

I use the gel roll that is available but will try more pillows to get more flexion.

Is that your needle coming in or a marker?

Thanks for the tip

 

[Orin]

I use the gel roll that is available but will try more pillows to get more flexion.

Is that your needle coming in or a marker?

Thanks for the tip

That's a needle just sitting at the skin surface. I draw a line along the genu on the anterior tissue from lateral/medial on the surface. That gives me where I think the plane to work in is for the block at least and then it's just a matter of finding the third axis/depth to get to half way.

I use gel roll under the heel of the foot as that helps me keep the foot from sliding down, but also lets me use my other hand to roll the leg in/out. At least one pillow bent in half under the knee helps a lot, as you need to get it up and away from the other knee for the lateral.

 

[deleted993114]

That's a needle just sitting at the skin surface. I draw a line along the genu on the anterior tissue from lateral/medial on the surface. That gives me where I think the plane to work in is for the block at least and then it's just a matter of finding the third axis/depth to get to half way.

I use gel roll under the heel of the foot as that helps me keep the foot from sliding down, but also lets me use my other hand to roll the leg in/out. At least one pillow bent in half under the knee helps a lot, as you need to get it up and away from the other knee for the lateral.

I only get about 50% responders with genicular rf after test blocks (1cc per nerve). Do you guys get better results? I have looked at the anatomy until I am blue in the fact and am pretty meticulous about my views.

Perhaps I just suck at that procedure.

 

[paindoc007]

I only get about 50% responders with genicular rf after test blocks (1cc per nerve). Do you guys get better results? I have looked at the anatomy until I am blue in the fact and am pretty meticulous about my views.

Perhaps I just suck at that procedure.

My % success for geniuclar rfa is definitely lower than lumbar or cervical RFA. I’m curious if that’s the consensus here also.

 

[Timeoutofmind]

I only get about 50% responders with genicular rf after test blocks (1cc per nerve). Do you guys get better results? I have looked at the anatomy until I am blue in the fact and am pretty meticulous about my views.

Perhaps I just suck at that procedure.

agree
and I have done a lot, with a variety of fine adjustments tried
i quit doing the test blocks because of this...i dont think they are predictive

 

[pastafan]

My % success for geniuclar rfa is definitely lower than lumbar or cervical RFA. I’m curious if that’s the consensus here also.

Not my experience. Surprisingly, I have never had a patient not have relief with diagnostic blocks. I do them to demonstrate to the patient the relief possible. Perhaps half a dozen failures out of 100-200 RFAs. I repeated one of them and the patient had good results. Thermal 80 degrees 120 seconds 10mm active tip 20 gauge. Leg not bent, elevated on a pillow to allow for lateral. These are my happiest patients as there is basically no recovery time after RFA with instant relief. Post images?

 

[callmeanesthesia]

Adding more burns seems to have helped a bit. I’d say my success rate (>50% relief) is somewhere between 50-75%. I do conventional RF, 18g needle, 3 burns, each 90 sec at 85 deg. I burn, turn the needle 180 (I don’t have venom or a similar system), burn, pull the needle back a little less than a cm, and burn again. I’m dropping diagnostic blocks unless it’s unclear if the pain is really from the knee.

 

[deleted993114]

Not my experience. Surprisingly, I have never had a patient not have relief with diagnostic blocks. I do them to demonstrate to the patient the relief possible. Perhaps half a dozen failures out of 100-200 RFAs. I repeated one of them and the patient had good results. Thermal 80 degrees 120 seconds 10mm active tip 20 gauge. Leg not bent, elevated on a pillow to allow for lateral. These are my happiest patients as there is basically no recovery time after RFA with instant relief. Post images?

Weird- I do about 4-5 lesions at each needle position (18g, 80 degrees for 90 sec), turning the needle and covering a fairly broad area. The best I can get is 50%- that's it. I guess I just suck at it.

 

[Agast]

Weird- I do about 4-5 lesions at each needle position (18g, 80 degrees for 90 sec), turning the needle and covering a fairly broad area. The best I can get is 50%- that's it. I guess I just suck at it.

I might be reading this incorrectly, but I don’t think rotating the needle helps in this case. I will start more posterior and then withdraw more anterior if I’m doing two burns in order to cover more ground of where the nerve may lie.

 

[onewithpain]

I get an occasional negative block but not enough that I save anyone money by not doing unnecessary RFAs. I use 18ga 1 cm active tip and place the needle just short of the dorsal aspect of the bone. I kill at 90 degrees for 60 seconds and then withdraw about 7mm and kill again and then withdraw another 7 mm and kill again. I get really good results, equivalent to lumbar and cervical. I have one ortho who has started referring patients for RFA and then he sends them to PT with the plan of replacing the joint after they develop a little muscle tone.

 

[thecentral09]

I get an occasional negative block but not enough that I save anyone money by not doing unnecessary RFAs. I use 18ga 1 cm active tip and place the needle just short of the dorsal aspect of the bone. I kill at 90 degrees for 60 seconds and then withdraw about 7mm and kill again and then withdraw another 7 mm and kill again. I get really good results, equivalent to lumbar and cervical. I have one ortho who has started referring patients for RFA and then he sends them to PT with the plan of replacing the joint after they develop a little muscle tone.

Nice. Mind posting some pics?

 

[ateria radicularis magna]

Not my experience. Surprisingly, I have never had a patient not have relief with diagnostic blocks. I do them to demonstrate to the patient the relief possible. Perhaps half a dozen failures out of 100-200 RFAs. I repeated one of them and the patient had good results. Thermal 80 degrees 120 seconds 10mm active tip 20 gauge. Leg not bent, elevated on a pillow to allow for lateral. These are my happiest patients as there is basically no recovery time after RFA with instant relief. Post images?

12 failures out of 100-200??? Are we living in different realities??? I do bipolar with meticulous placement for each nerve and my results are nowhere near this! What’s the secret sauce dude ?

 

[painfree23]

Adding more burns seems to have helped a bit. I’d say my success rate (>50% relief) is somewhere between 50-75%. I do conventional RF, 18g needle, 3 burns, each 90 sec at 85 deg. I burn, turn the needle 180 (I don’t have venom or a similar system), burn, pull the needle back a little less than a cm, and burn again. I’m dropping diagnostic blocks unless it’s unclear if the pain is really from the knee.

Do u do these under sedation?

 

[pastafan]

No sedation, a lot of local as I advance needles. I also define success as 50% or greater pain relief lasting at least 6 months. Most patients get closer to 1 year relief. I have a few with over 4 years relief for RFA S/P arthroplasty. The 50% crowd get with topical diclofenac and that helps.

Secret sauce, I don't know? I do single burns. I have posted images before. Truthfully, I am amazed that without as well defined targets as spine RFA results are so good.

 

[painfree23]

Man I can barely get a 22g in without them complaining. How do u get a 18g in! Also, sometimes as I’m inserting the needle I feel like on the AP image I’m in the right location but I hit bone too early, so clearly not in the right spot and need to go more lateral ...but the AP image looks off. Any suggestions? I usually keep the leg raised but knee flat (not bent)

 

[callmeanesthesia]

Man I can barely get a 22g in without them complaining. How do u get a 18g in! Also, sometimes as I’m inserting the needle I feel like on the AP image I’m in the right location but I hit bone too early, so clearly not in the right spot and need to go more lateral ...but the AP image looks off. Any suggestions? I usually keep the leg raised but knee flat (not bent)

Xanax for sedation. May ditch that or only do it if they ask for it though.
The key for me is using a 27g 1.5” (longer needle if fat leg) from lateral/medial aspect of leg down to the target point, and injection 2% lido to anesthetize the periosteum. Then I localize the skin and come in from straight AP. If you just go for it from AP, it seems really painful even with a 25g needle for the block.

 

[oreosandsake]

stryker, bipolar, venom. I do 2 rounds each of the top two. then move one of the needles down to the inferior one, burn again, then sometimes move all needles again for a 4th burn. 85 for 90. takes time and money but outcomes have been great.

 

[Ducttape]

I guess I'm going too inferior...

 

[painfree23]

stryker, bipolar, venom. I do 2 rounds each of the top two. then move one of the needles down to the inferior one, burn again, then sometimes move all needles again for a 4th burn. 85 for 90. takes time and money but outcomes have been great.

is the injecting leg positioned straight or bent? how do you know you are straight AP on the knee AP?

 

[lonelobo]

12 failures out of 100-200??? Are we living in different realities??? I do bipolar with meticulous placement for each nerve and my results are nowhere near this! What’s the secret sauce dude ?

Like most anecdotal success stories on these threads should be taken with a healthy dose of NaCl

 

[oreosandsake]

is the injecting leg positioned straight or bent? how do you know you are straight AP on the knee AP?

knee flexed to 40-45 degrees. you move the Image Intensifier for AP onto the femur, or AP onto the tibia. straight AP for the knee, the patella should be centered between the condyles

 

[Ligament]

Not my experience. Surprisingly, I have never had a patient not have relief with diagnostic blocks. I do them to demonstrate to the patient the relief possible. Perhaps half a dozen failures out of 100-200 RFAs. I repeated one of them and the patient had good results. Thermal 80 degrees 120 seconds 10mm active tip 20 gauge. Leg not bent, elevated on a pillow to allow for lateral. These are my happiest patients as there is basically no recovery time after RFA with instant relief. Post images?

My experience is similar. However, I'm quite sure that a lot of the relief comes from placement of local anesthetic inside the suprapatellar pouch. Still, it works.

 

[Bsb2015]

Xanax for sedation. May ditch that or only do it if they ask for it though.
The key for me is using a 27g 1.5” (longer needle if fat leg) from lateral/medial aspect of leg down to the target point, and injection 2% lido to anesthetize the periosteum. Then I localize the skin and come in from straight AP. If you just go for it from AP, it seems really painful even with a 25g needle for the block.

I adapted this to my technique and it worked well.

 

[Sadder]

Accuracy of fluoroscopic-guided genicular nerve blockade: a need for revisiting anatomical landmarks | Regional Anesthesia & Pain Medicine

 

[SommeRiver]

12 failures out of 100-200?

Are we at a NANS meeting?

 

[deleted185747]

I started doing dx genicular blocks from lateral approach 4 years ago and have been teaching the fellows my technique. Is anyone else doing it this way?

It’s less painful for the patient because there’s less needle in the patient, no scraping os to get deeper and less time there’s a needle in the skin.

 

[callmeanesthesia]

I started doing dx genicular blocks from lateral approach 4 years ago and have been teaching the fellows my technique. Is anyone else doing it this way?

It’s less painful for the patient because there’s less needle in the patient, no scraping os to get deeper and less time there’s a needle in the skin.

I do, after seeing it on a previous thread here. Made a big difference. Now though for patients where the pain is clearly knee, I just go straight to ablation. I mainly do ablation for people who are out of options - already had the knee replaced or can’t have it replaced, so even a few false negatives on diagnostic blocks is unacceptable to me.

I incorporated a block from the medial/lateral approach with 2% lidocaine prior to putting in the RF probes too though (conventional RF, from straight AP) and that made a huge difference in the ability to comfortably place the needles by anesthetizing the periosteum.

 

[callmeanesthesia]

Accuracy of fluoroscopic-guided genicular nerve blockade: a need for revisiting anatomical landmarks | Regional Anesthesia & Pain Medicine

Is anyone using these landmarks? I’m going to give them a try.

 

[pastafan]

I started doing dx genicular blocks from lateral approach 4 years ago and have been teaching the fellows my technique. Is anyone else doing it this way?

It’s less painful for the patient because there’s less needle in the patient, no scraping os to get deeper and less time there’s a needle in the skin.

Same here. Posted technique in another thread.

 

[deleted993114]

Accuracy of fluoroscopic-guided genicular nerve blockade: a need for revisiting anatomical landmarks | Regional Anesthesia & Pain Medicine

THAT was a fantastic article. Thank you very much for posting that.

So...................... speak to me as though you are talking to a 10 year old (that is the limit of my intellect). After reading the article, am I correct in saying that the classic description of the procedure:

1. Places the femoral condyle needles too far superior?

2. Places the femoral condyle needles too shallow?

Again, after reading the article, the classic description of needle placement appears to be too "shallow" and too far superior, is that correct? It appears as though the tibial placement is close to the classic description. Is that correct?

 

[Tramadeezy]

Is anyone using these landmarks? I’m going to give them a try.

Great article. Seems like you may need some oblique tilt on the c-arm if going that inferior on the condyle in order to keep your RF needle in contact with the femur as you advance that far posteriorly?

 

[pmrmd]

Is anyone using these landmarks? I’m going to give them a try.

Awesome find bro. I was giving up on this procedure because the results sucked.

 

[TIVAndy]

Is anyone using these landmarks? I’m going to give them a try.

this is why i love this board. it's sort of lonely as sole practitioner not able to bounce ideas but i learn a great deal from here. I always tell my patients that my success rate is 50-60%. sometimes i've done bilateral where one knee gets better and the other doesn't.. anyways i'll try to modify my technique according to this article and see if my success improves..

 

[likeaboss]

this is why i love this board. it's sort of lonely as sole practitioner not able to bounce ideas but i learn a great deal from here. I always tell my patients that my success rate is 50-60%. sometimes i've done bilateral where one knee gets better and the other doesn't.. anyways i'll try to modify my technique according to this article and see if my success improves..

i would like to skip the diagnostic block and just go straight for the RFA. is this an insane idea for medicare patients?

also i saw a patient who i did genic RFA for 3 months ago who got about 50% pain relief for 3 months. She is a medicare patient, can I repeat this every 3 months or does it have to be 6 months like medial branches?

 

[callmeanesthesia]

this is why i love this board. it's sort of lonely as sole practitioner not able to bounce ideas but i learn a great deal from here. I always tell my patients that my success rate is 50-60%. sometimes i've done bilateral where one knee gets better and the other doesn't.. anyways i'll try to modify my technique according to this article and see if my success

i would like to skip the diagnostic block and just go straight for the RFA. is this an insane idea for medicare patients?

also i saw a patient who i did genic RFA for 3 months ago who got about 50% pain relief for 3 months. She is a medicare patient, can I repeat this every 3 months or does it have to be 6 months like medial branches?

Check your Medicare LCD for the 64640 CPT code. Not sure how this will all change with new codes though.

 

[likeaboss]

Check your Medicare LCD for the 64640 CPT code. Not sure how this will all change with new codes though.

Medicare LCD didn't give any guidance on this. I'll just wait until 6 months to burn again...