- Okay so thank you Bob. I have lots of conflicts. (coughing) You know that's just because I've invented a lot of devices. And there are about 64 patents on different things. And the only reason I do that
is because unless like-- if you always say yes you wind up doing things that are challenging and then to find the answer to that clinical problem you wind up inventing a new device.
And then to share that with other people you have to have somebody make that thing. So for an inventor a relationship with a company is the same as a publisher and the relationship it has with its author.
Right? So it's never about money it's actually just about having an impact. For example the Cook things are used in about 1600 hospitals a year worldwide
which is really useful. So I see vertebroplasty as an embolization of a vertebral body, of the trabecular space of the vertebral body, with a liquid polymer that solidifies.
And what interventional radiologists, interventional neuroradiologists do, are embolizations. So we should see it as an embolization with potential extravasation and philosophically that fits very well with
how we approach embolizing meningioma, or a juvenile angiofibroma, or something else. And it fits into so you're looking for reflux,
you're looking for venous drainage, you're looking for some kind of change over the baseline image as you do the procedure.
Compression fractures are one of the leading causes
of admission to nursing homes. Every Tuesday afternoon I see seven to eight patients. And they boil down to two groups: One are the Tarlov cyst group, and the other are basically
elderly people with back pain. And that group have either spinal stenosis or compression fractures. And the easy thing to fix, in many ways, are the compression fractures.
The spinal stenosis in the elderly is really difficult. But these people are just like you and me except somehow, chronologically, based on their date of birth, they've gotten old.
There's nothing wrong with their brains they just have a mechanical transport problem, yet if we don't fix it they wind up in a nursing home and then they die. And if you look at the fate
of somebody who goes into a nursing home within at least two to three years they're dead. They wind up in a wheelchair facing a wall and they're dead. And it's such a shame when it's just a simple mechanical problem
that we can fix. And their lovely people to look after. It's a great generation to look after. One of my patients last week was 96. I'd say biologically he was about 76 and he had served as an able seaman
on a Royal Canadian naval vessel crossing back and forth across the Atlantic in the Second World War. You never meet people like that, you know? So it's a great generation. The patient on Thursday,
she was Head Girl at Havergal in 1940 and you could still see it. You know, you could see in her that she was still Head Girl. You could see the behavior and the mindset and everything,
and yet their age caught up with them. So it's wonderful to look after this patient population
and it's wonderful to do something that has such an immediate impact. But there are lots of fractures.
There's about half a million a year and 2/3 of these will get better over four to six weeks. And 1/3 are the group that we treat. However I think all of them are probably candidates for what we do
and that there's a certain degree of nihilism about this, because if you put an elderly person in bed for six weeks they have such massive muscle loss. Their quads disappear,
they can't get out of chairs, they get all sorts of UTIs, pneumonias, and everything else. One day, perhaps, we'll do all these procedures within 24 to 48 hours,
and they'll just go home from the emergency room and they'll never be on opiates and we'll be able to keep them really really well. And I think that's what we would want for ourselves. When you look at these vertebra you divide them into thirds.
There's the anterior, the middle, and the posterior column. And this is essentially where you want your cement to be. There's no weight bearing back here. And you certainly don't want any cement back here.
Remember this is concave circumferentially and posterially. So you focus on the anterior and middle thirds of the vertebra. There is some language around the fractures that occur in vertebra
and there are different scoring systems that talk about where these fractures are. You have anterior column fractures, middle column fractures, posterior column fractures. And there are complex--
sorry I screwed that slide up. But there are complex mechanisms involved here and we're basically looking for just simple superior end plate anterior compression fractures. Not distracting forces
where the posterior elements are rotated and distracted, or rotational fractures of the vertebral bodies.
So there's a classification system that's commonly used for this called the Maegerl Classification
from the a AO organization and we're going to be treating patients in the simpler group of fractures and sometimes we go into other areas that are more complex but in the beginning
when you do these things you're just going to look at simple compression fractures the A-classification of these fractures where there's wedge compression of the anterior superior aspect
of the middle portion, or perhaps of the whole, vertebral body but there isn't an element of distraction of the posterior elements or rotatory components of the fractures. Now we often see people
with spinal hardware like this and sometimes this will be a laminectomy decompression fusion for metastatic disease with a cage and patients don't do well after this and frequently they will pass away
from their metastatic disease before they heal from the impact of a surgery like that. But they also fracture above and below these constructs because all the force is shifted
to above and below these rigid pedicle screws. So often we will augment vertebra above and below a fusion to make sure that they don't go on to compress these.
The needles involved,
well these are mine, but, they're simple, right? They have either a bevel or a diamond tip and they are either 11 or 13 gauge in diameter. And gauge is the number of things you fit in an inch.
Or they can be 16 gauge for the cervical spine. For us, the pedicle, I imagine the pedicle like the femoral artery of the vertebral body. And once you get in the pedicle you can go anywhere you want.
If you stay between the walls of the pedicle you can't hurt anything. So imagine you're doing the luge and you're going down one of those chutes at the Olympics. You're going to stay between here
and you just slide. And you never breach the medial cortex of the pedicle. You oblique the x-ray tube to get the largest view of the pedicle you can. And you translate from superior laterally,
at around 10 o'clock, all the way down to around four o'clock. You pick the position on the pedicle with regard to where you want to land the tip of your needle. And it's like flying an airplane.
You're coming in in your little Cessna 172 you know where on the runway you want to be, and then you position your needle to get to that point. That is the most important part of the whole procedure.
If you get that right, you're done. If you're in the wrong place in the pedicle, sometimes it's really hard to reposition it because you've made a divot somewhere in the pedicle and your needle keep slipping back into it.
And often what happens is that, frankly, the Fellow might get that bit wrong and then Roger or I will have to sort that out. If you've got a beveled needle and you're in the wrong place you can take a diamond-tipped needle
and then position it because it'll just grip better. Okay? So you translate down the pedicle. And once the tip of the needle is here at the junction of the body and the pedicle
it's permissible to see the needle translate medial to the medial cortex. There are some cool things about doing vertebroplasty. There are sounds that change. Roger thinks I'm slightly mad about this
but when you're tapping away on the periosteum back here at the pedicle it's like when you're trying to crack a boiled egg. And then when you get into the pedicle itself the sound drops,
the timbre of the sound drops, like when the egg shell cracks. And as you get to the pedicle body junction here, the sounds change too. It increases slightly and then it drops again.
And as you abut cortical bone, or sclerotic bone, in the vertebral body, the sound will change as well. I always use a hammer because hammers give you more control
than your hand. You move with your hand, it wiggles. A hammer will let you tap. So you begin with the landing position in mind and you translate down the peticle and you advance into to vertebral body.
And then you wind up in the appropriate place, the junction of the anterior and middle thirds. And then you inject cement.
And then you inject cement. And that is the embolization piece. And that's when you look for things like this, which is the filling of the vertebral body,
basivertebral plexus, which can go back into the epidural venous space. There are clearly bad things that can happen when that happens. Ironically
that's also the anatomy of the distribution of the basivertebral nerve which innervates the vertebral body. Orthopedic surgeons used to say vertebra had no innervation. Just stupid.
Everything's got innervation. So you have the sinuvertebral nerve innervating the cortex but within the trabecular space it's the basivertebral nerve which runs along with the basivertebral vein.
And that arborizes, or branches, within the vertebral body, innervating it. And as the cement polymerizes to up to 80 degrees centigrade it ablates that nerve making the inside of the vertebral body anaesthetized.
I can't say that word. So you wind up with two nice dense deposits of cement. If you can, bridging from superior to inferior, but it's always about distribution not volume.
Complications are related to volume. Pain relief is related to distribution. You can always do more but you can never do less. You know if I could've prevented myself
from putting in the last coil of an embolizing aneurysm or the last cc of cement when we're doing a vertebroplasty I would have had-- I haven't had many complications
but I would have had far less. So you can always do more and patients will allow you to do more. You'll have a lot less explaining to do if you under achieve than if you over achieve
and have a complication. So you look all the time at the distribution of cement. And here you see nice cohesive distribution of cement.
The explosion of the growth of this procedure
is remarkable. When I ran the first meeting on it in North America there were about 40 of these done a year in North America, driven mainly by patients. So there's lots of papers on this
all showing high success rates in the eighties and nineties. So no surprise there. Papers from, gosh, a surprisingly long time ago, showing 80-90% success rates. If you look at the work-up of the patient
sometimes it's a challenge to our infrastructure. This hasn't changed. Patients show up with studies on disks that w it's a pain in the ass.
There's a great system-- a great software called RadiAnt, it's a free download DICOM viewer that I use. It opens everything within about 30 seconds. So RadiAnt Viewer. It's much quicker than our Coral system
and it can open any disk, but you evaluate plain film, CTs, MRI, MRI with stern imaging is particularly useful. If you're in doubt, if you're not sure if somebody really has pain sometimes I'll get a bone scan.
Sometimes I'll examine them under fluoro and see where their pain is.
The ideal patient has a recent or isolated fracture with mild to moderate height loss and no degenerative disease.
And you rarely see somebody like that. The typical person has multiple or old fractures, many with severe loss of height and extensive degenerative disease. Roger and I have a different philosophy about this. I might d
he might do six levels. But that's why medicine is an art, not a science. You know, W.H. Auden said, "Medicine is the art of wooing nature,
"not the science of healing." And so we have different ways of doing things that reflect our own experience.
Inclusion criteria, pain resistant to medical management. And you can tell
when the patient walks into your office. Did they walk in? Did they come in in a wheelchair? Were they pushed in? Are they taking any medications? If they're not taking any medications
and they walked in, why are they there? If they're coming in in a wheelchair and there's somebody with them, then that's a different level of-- or if they're hospitalized in pain
because they can't walk and they can't support themselves. Those are all things that push you towards doing something. We have no age limit. My oldest patient's been 103.
Roger, what's your oldest patient? Yeah? Cool. See, if you don't do this they won't get to be 98. And we have no height requirement.
(chuckling) We treat short patients. (audience laughing) That's not what I meant. Yes that would be wrong. Yeah. Since I've moved to Canada I have to be more--
my daughter give me lectures all the time about what I can't say. And we've no time limit from the point of fracture. Exclusion criteria would be infection,
Exclusion criteria would be infection, coagulopathy.
Infection is tricky, and these folks, they can have a UTI. They can have a little cellulitis, a little pneumonia. And you don't want to
put a foreign body implant in them if they have that going on. Coagulopathy. I don't worry about Plavix and aspirin but I do worry about INRs above 1.3, 1.4 and I stop all the apixabans and everything else
because they're a nightmare. In North America we treat mainly osteoporotic fractures. We do not treat enough malignant fractures. That's because people get radiation followed by a different kind of radiation,
followed by a different kind of radiation, followed by a different kind of radiation. It's a weird culture and that really has to change. In Europe this is primarily an oncology procedure
with a it's the inverse of this, a small number of osteoporosis.
The most important thing is to make the patient comfortable.
The more comfortable the patient is on the table you have a huge reduction in the amount of sedation you have to give the patient. So if you have a table with onboard extensions so they can lie comfortably
kind of like an inverted Starship Enterprise. If they can be comfortable on the table with lots of pillows and for many of these people they haven't lain on their face-- lied on their face, or been on their face
in the prone position for 30-40 years. But if you can get them comfortable then you can drop from three or four milligrams of Versed and 200 mics of Fentanyl to a milligram and 50
and then you have far less problems with respiratory depression and confusion and agitation and all those things you don't want older people to get. So make people comfortable.
Sometimes I've done these things with people sitting up. And this poor lady was so kyphotic that even if she laid flat-- you know, my needle would be coming in horizontal to her skin.
And so it was easier to sit her where the head goes on the table. And she weighed nothing. I put her feet on a box and brought the AP tube around than to try to get her to lie flat.
It's interesting to look at the distribution of osteoporotic fractures basically between T8 and L2. And that's where the weight bearing is. That's where most of the motion is. And if I could prophylactically augment somebody
at very high risk, lung transplant, liver transplant, that's where I would do it. You know somebody with-- sometimes you see a person with fractures at a couple of places and a normal vertebra in between.
And you know if they fracture that one they're just going to go like that. So these are the folks who, T8 and L2 and osteoporosis, metastatic disease, that the med is usually related geographically
to the location of the primary. So if it's prostate or colorectal it'll be lumber. If it's thoracic it'll be a thoracic med. A lung med it'll be a thoracic med.
With the breast med it might be upper thoracic or cervical spine. So there's usually some kind of geographical relationship with the origin of the lesion.
And this is just
a series of 205 patients I did in 2002. A portion of 2002. And that they did well. You can image-- sorry. You can have patients get worse
if you injure facet nerves. The innervation of the facet joint and you bugger them up. And if that's the case then you can do facet blocks and get rid of that pain.
You have to watch for rib fractures when you do this particularly in very very osteopenic people. When you put them on the table, when you get them off the table. I hate when patients who are elderly
roll off tables and their humorous is under their body. You think you're going to fracture their humeral neck. You have to be very careful with things like that. Cement can cause hypotension. The monomer can get intravascular
and cause hypotension. You always have to watch too for pulmonary emboli of fat to the lung as you displace the volume of fat in the vertebra. The oily lubricious fat in the vertebra will be displaced
by the volume of cement you inject. (coughing) In people with pulmonary hypertension that could be enough to tip them over into a decompensated state.
In metastatic disease,
Roger's going to talk about this, but these patients are memorable. Which is important for us to sustain us during prolonged periods of stress. When you remember the good things you did in your practice.
This patient was General MacArthur's adjutant in the Second World War. I'll never forget him. And he went on to run Dow Corning. An amazing man. He was on, like, 32 Oxycontin a day.
There's no correlation between wealth and pain, or wealth and pain management. It's amazing how people who can have Gulfstream Vs can still get terrible health care because they don't pay enough attention
to their health care. So this person was interesting. Cement can flow through tumor and tumor can be contiguous across end plates. So this is cement flowing from one vertebra to another.
But when you see that you kind of go, "What the hell? "What have I done? "Does this makes sense?" and you stop until you understand it. And anytime anything happens
that you don't understand, you stop. Like you don't drive when you can't see the road ahead of you. So this is cement flowing through from one vertebra to the other and I needed to do that one anyway
so I continued to inject. But you need to stop and understand what you're doing. Okay, and then I put another needle in above that and finished it off. So you wind up with something that looks awful. But is effective.
But you must understand what you're doing.
Hemangiomas are benign but they can have malignant behaviors. The important thing about hemangiomas, this involves the body and the pedicle, is that you've got to follow these people.
These are young people usually who have painful hemangiomas. I remember this kid. This kid was from Buffalo and I wonder where he is now. When you move hospitals
you lose track of your old patients. It's a problem. But the thing with these things is they continue to grow slowly, persistently, and sometimes they'll come back with cord compression
but they don't have back pain because the cement is giving them stability. So you've got to keep an eye on hemangiomas. You don't just treat them once. You've got to follow them up. And this is a vascular space
that you're going to embolize with bone cement. So in this situation because I wanted to do the pedicle and the body I needed to figure out how to inject the pedicle and the body and have control.
And so I decided I would put in two needles down the one pedicle. One in the pedicle and the other going into the body. And I injected the pedicle first because I knew if I injected the body first
I wouldn't be able to see the pedicle. So when you do something a little unusual you think it through and you stay awake at two or three in the morning and you percevorate until you develop a technique
that lets you do that thing. Okay so that's what it looked like in the end. I injected this first and then that because if I injected that first I wouldn't be able to see this, okay? So you think through what you're going to do.
Lytic pedicles you can augment. This is a farmer who is 80 from Pennsylvania who lifted a big bag of corn and hurt his back and I asked him why he did that and he said,
"Because it had to be moved from here to there." So these are healthy people who-- he turned out to have multiple myeloma. If you see osteoporotic fractures in men biopsy them because about 11% of them
will have an undiagnosed, underlying multiple myeloma or plasma cell dyscrasia. The most common reason for osteoporosis in men is alcoholism. And after that, steroids and rheumatoid disease and all that.
But then you have to be conscious of this fact that the plasma cell dyscrasia may not be diagnosed yet and do those biopsies. This is just augmentation of the pedicle with fluoro-guided deposition of cement
and this is the CT afterward.
Does vertebroplasty cause adjacent level fractures? Essentially I don't think so. I think people have systemic diseases. If the cement is contained within the vertebral body,
it doesn't. If you get a lot of cement in a disk space certainly it can. But if you look at the literature and you look at the information on drugs, for example strontium ranelate,
the natural history of people with a vertebral compression fracture show that even in the placebo group there was spontaneous fractures. And the data around having another fracture if you have a fracture is interesting
because with one fracture the risk of another fracture is about four times elevated. If you have two fractures the risk of another factor is seven times elevated. If you three fractures it goes up more. And fractures are associated with a 40% mortality.
The only thing worse than that are like subarachnoid hemorrhage, hip fractures, and funny enough, rib fractures. We were just talking about this last night. I'd love to fix rib fractures. Roger and I have talked about this.
An elderly person with four rib fractures has a 40% mortality. So we need a procedure for that. So why does vertebroplasty work? It's the cement heat, it's the stability,
it's the toxic monomer. I don't believe in adding antibiotics to cement because I don't think they would survive the polymerization. See, that patient was 97 though. He wouldn't be with us anymore.
That's a patient from 1999. But I do remember him. Did the did you see the cement in the end plate causing a fracture at the level above? You've got to not let that happen.
So complications. These are just some complications. CT fluoroscopy is not an adequate method of visualizing-- these these are cases that I got from the literature or from colleagues or medical legal cases that I was sent to review. Always the issue is the quality of your imaging.
If you've got crap imaging you can't see where the cement is going. Our current Philips biplane room is awful. Our old Toshiba room was better. So this is cement being injected under CT fluoroscopic guidance
that extravasates into perivertebral veins and epidural cement there, okay? But the problem is that the amount of extravasation seen on the CT because of the limited axial coverage
doesn't really capture the amount that was really there. And that's a problem. That's potentially paralysis. Beware of portable C arms. You'll see image coverage is often--
the image quality is not adequate. So here you see cement in a vertebra. The patient did not move their legs after the procedure and the CT showed all this bone cement in the epidural space
that you really just cannot see. You can see something here but the scale of what's going on there is not adequate.
is not adequate. We did some animal work and things and basically what we were able to show
was that, at its very best, (coughing) in cadaver bone when you took a vertebral body of this height and you compressed it to this height and you did a kyphoplasty
you got back about three millimeters. That's meaningless. There'll be multiple papers showing that the height restored is not retained.
There are multiple factors in bone cement
that you can manipulate and if you manipulate those factors you can change the viscosity. This would be cohesive. This will be filling of veins and extravasation. What you want
is some cement that intercalates or intersperses within the trabecular veinous space. Remember that when you take out a vertebral body the patient can lose one to two liters of blood. It's a veinous space.
And that it'll stay cohesively within the vertebral body. So you can play with permeability and viscosity and porosity of the cement. I like the defined cement a lot. I've always liked it
because if you look at these images you can see that the very cohesive cement can actually move bone fragments and restore height. So I admire their engineering.
I have no personal benefit from anything that Merck does and (coughing) I guess maybe I do because I'm Atlantis. But you know I just, intellectually, I admire their engineering.
So this is a series of experiments they did a long time ago at Brown in Rhode Island in their cadaver lab looking at defined and then kyphoplasty and vertebroplasty
and looking at the ability of cohesive cement versus balloons to restore height by elevating end plates when the bone is actually under pressure in an Instrom string gauge. And we could prove that it did do that.
I made a highly exothermic cement for tumor that polymerizes to 88 degrees. So that you have a cold cement for benign disease and a highly exothermic one for malignant disease.
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