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A-1165 Limited wrist fusions - principles and option to maintain motion
Greg Bain, Australia
Friday, June 15, 2018 · 10:34 a.m. · 22m 00s
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this is a great group it's it was printed on i make a a
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group of my involvement is certainly not as much is for it's
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but it's been a great place to be involved in fact which when i think we need to acknowledge is contribution to setting it up
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so i'm gonna talk about um some would would be on the finnish university in atlas trying to
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and i'd like to acknowledge uh that might take can have sponsored
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this study so there's a for that's important i think
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uh and these are the preliminary results which religion been working on the last couple of months to create that
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um so it sits we mac uh is the the sponsor of this particular study that provided funds to the university
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a first generation after place these uh start off with swanson went into the
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second generation bought as in the vaults top of after class these
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kyle and subsequently to the third generation we've seen some of those presentations during this meeting with regard to those
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fourth generation uh prostheses include the motive prostheses which it has
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a different top of articulation has a spherical ball this
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is the other topic prostheses on the left which a time to be more of an actual top of articulation
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they might take prosthesis initially began in two thousand six
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as the given prostheses it was subsequently renamed
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it's a titanium alloy prosthesis and it's blasted uh and it's got
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a special coating on it uh which uh apparently will dissolve
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in part and improve the bonn a union onto the prosthesis i'm not aware
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the exact details of that uh uh from a technical point of view
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with regard to the prosthesis it's a screw in prosthesis
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and this creates a metal on metal articulation
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metal metal articulation the been a controversy you a topic particularly in the
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hip this is a cobalt crime articulation and its spherical in shape
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uh we would would postulate naturally that the uh centre rotation would be at the centre of the
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the head of the ball uh and so part of this study is to assess that
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we know from the studies or the manufacturer that to the they'll be
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impinge mccall the prosthesis as it goes to the uh extremes
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of motion which would be i. q. degrees for the long and standard neck and sixty five degrees for the short neck
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they have been a number of uh studies on the motive prosthesis uh none of these studies were also an author on
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the first one was of thirty five patients they had a a improvement in
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the clinical outcome a grip strength dash goal is and kind schools
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the complication right uh uh three patients uh at other
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thirty five patients had concerns to which record revision
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this more recent study uh demonstrates results at the ten years
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and that we can say that uh that the results of being able to uh
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mine time that outcome uh in fact i'm sorry of delay the slot
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with regard to the captain ma as scores but uh my recollection was uh
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that i mind kind a good captain more schools uh at that
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with regard to the striding joint registry this is the data that comes from our registry
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from two thousand thirteen two thousand sixteen and this demonstrates
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a an increase in the use of the prostheses
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from twelve through twenty five so in this three year period has been more of a doubling
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uh more than doubling of the use of this top of the other stuff to plastic
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and my take prosthesis as we can say is gone from like through the fifteen
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and and that was the most commonly used prosthesis in in the strata
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this was the slaughterhouse just looking for a ten year survival uh with that uh the study was id six percent
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from the um norwegian joint registry the results are actually quite different before your results us of
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authorship is seventy seven percent so that's quite in contrast to the other probably studies
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yeah i'm of this study is to perform upon mechanical comparison between the the
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normal wrist and the and the mo take after past the wrist
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this is the kind of eric study on ten specimens uh the
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uh the specimens were able to identify details about the specimens
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and it's interesting to note often think on a more about marquette of eric specimens then my patients
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you can say that with the bikers were from forty to sixty i'm not i will us like
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that in my patience we know that there's not prior injuries also it really have extras available
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and they'll a wee rabbit actually get matched pays in many cases
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with regard to the preparation we start of pop preparing specimens to be
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able to to the data for the details of the normal wrist
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the specimens with or that we performed uh and uh uh you excise
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some of the soft issues so that we could then clamped
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uh the uh the specimens and we put a into parts would put a mate on the factor light
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so they got a a strong grip between the made some effect correlate the bind and then that is an added into the machine
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yeah we took standard floors copy images as demonstrated and that we can
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say here from the positioning of the uh of the uh of
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the radius and the cops were ever identify comparison of the cement
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blocks to be out of the term the centre of rotation
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and we put the process that the um the the released into
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this tech support tech support is based on the stuart platform
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and those of you who uh to a lot i'm i'm a troll work we know about the steel platform
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is used for lynn length a correction with regard to
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the abnormal a deviated to uh to deal
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uh where i would reconstruct the positioning of the uh the tibia with these external fix eaters
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it's also the same concept is using this as a flight simulator the
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flight simulator we have a price and the another level and
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has six actually why it is that the in an eyeball the
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uh the superior aspect to move in an o. dimensions
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it has i would it do this with considerable degree of precision data twenty a marker made is
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in six degrees of freedom and because it has the actual right is
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it's i would measure the forces and moments that occur within the within the wrist
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we did a three studies on these first one was a flexion extension
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uh right now the deviation and that throws motion you can actually see the the uh the wrist within the heck
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support the the moment you can see what's moving through and
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that we created three cycles with each branch motion
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it's important point out that uh from a scientific point of view that the range of motion
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within the hicks apart is limited because of the uh of the constraints and this of
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and and and eyeballs that we can only review up to say twenty degrees of
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flexion with twenty agrees extension so it's not the full arc of motion
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we tested the normal uh wrists we we took them through which we calibrated the wrist in
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position of full so there's no for such a level of the going through the rest
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been twenty degrees of pretty low this place or the wrist and then it's taken three one a motion
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go back to neutral have a motion and then finally got froze motion
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so the concept involves that were i would uh to take the wrist and
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move it through a sign configuration uh from flexion extension flexion to extension
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this demonstrates a lot for either of what we say oh what this on to say at the time all performing the uh
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uh the assessment and you can see hats i would uh literally graph
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uh the details the position of the wrist in different configurations
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and this is the sort of died of their engineering stuff uh obtain
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so that on your top uh right you can say this is
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without throws motion so that had the computer assesses flexion extension
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that's also a a radius regulation our deviation because of course
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a position of that for as much does not
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just the um right you'll round deviation goes and both
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times the bottom uh uh left image uh demonstrates
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the bottom left image demonstrates an interesting uh aspect of this
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device so you can say that green line here
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this green line is interesting because what it does is because the
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computer uh directs that is uh uh fifty degree new and
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force on the wrist has the wrist moves in various position it mine kinds the fifty degree newton force across the wrist
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and then uh this is the of the position or the data that's collected is with regard from actual weight
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as as the force and a moment i'm sorry go to that that are measured within the boss
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but what we're really interested in is the migration or centre
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of rotation translation so this demonstrates in the tape lines
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in a flexion extension plan and the radio on applying the change in
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centre of rotation of the raised throughout the range of motion
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so the accuracy the machine because of the way that the actual ad is work is uh
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incredible really it's the tree to the a zero point zero zero one uh all the
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degree and and very small aspects with regard to the uh the measurements as well
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the surgery in this study all surgery was performed by
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doctor marcus solomon from a cut down south africa
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and he actually fluent adelaide uh or you can say on assisting in their mark
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always experienced a hand surgeon he's experience with the the might take prosthesis
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uh he is not aware of the details of the study infected
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eyes the very first time he saying any results of it
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uh he is uh are blinded him outside and uh all i think
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he's done approximately thirty cases um he moralistic written on that point
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but they're all good he tells me that mark was a very experienced surgeon
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so he's actually blind obese lawn to the outcome is not lawn to the city which is probably a good thing
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with regard to the technique that he used in these uh photographs of him performing the procedure
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uh the he's the dos approach you did approach more a cop picked me you can see his identifying on the first
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topic image where he thinks important position is to ensure that you get the creek lined up with another couple
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there's a rumour that comes uh is provided by the manufacturer and then the prosthesis is secure into position
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um i must point out that uh marco as as a surgeon's experience surgeon
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the technique that he uses is not that generally you used for the uh manufacture
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so we have the the binary section is these are the manufactures brochure the binary section we can say here
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and that we can at the recommendation is to take out the articulation between the third and
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a couple neck appetite to elevate tech appetite to create a lauren through this so
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the that particular day tell from a um academic point of view is is probably least important from it
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someone's point of view whether it's relevant and out come and cracked this is is another completely different thing
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because marcus inexperienced surgeon and mike cyclical choice
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so with regard to having a perform the procedures for ah c. p. all the response to form
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so some basic data that would be no tine from the first topic
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assessment it's interesting to say that the couple hot is increased
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of the auto five millimetres so it's actually makes the wrist a little bit longer but of course this is a time zero and it might
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be that with tom that in fact that the wrist does concertina down
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a bit with absorption of the uh the the byron the prosthesis
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the centre of rotation as identified on the pipeline first topic images going
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back to sort of technically more than when you were in school
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demonstrates that like appetite eh i hate is the centre of rotation which is different from that published in the literature
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and it's approximately five millimetres this to to the uh the ready uh it's hard to the lunatic appetite joint
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uh and so that was i think an interesting finding and that we can say that there
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is some variability as to how the prosthesis was inserted throughout the spectrum of the crisis
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this interpretation is approximately a six millimetres does too
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to uh with a normal draw the line would would base so six
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minutes proximate with the joint one would normally be for this interpretation
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this demonstrates affliction extinction loan displacement curves and you can see the point really
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just one might this lot is actually quite a degree of variability
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but i think that might be part of the uh of nigel with always moving slightly differently
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but we look at the back idea of all the wrist put together from a scientific point of view we can say that the stiffness
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through the uh articulation is not significant to that of normal but uh
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with regard of uh to flexion but in extinction is statistically significant
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and with look at the energy absorption that goes through the pro uh the process
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places we can say that that is statistically significantly different from that of normal
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and from an engineering point of view the calculation of the uh this of this
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uh energy absorption is effectively the volume of the history says curves are created
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so we go now to looking at a radio on the deviation like in the
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some changes in stiffness but when you we think about articulates surfaces generally
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um i have lot extremely low friction so i think to be i would be
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even so the look compare wanna graph is is is probably pretty good outcome
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so the energy rebuilt again however is is statistically greater than that of uh the normal wrist
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so if we go on a diet froze motion so uh this is the other the wrist is
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moving in with that throws motion the computers measuring only the flexion extension pine in this craft
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so we say here that uh again the stiffness it's statistically significantly different and the energy absorption
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and the type of the shows five point three this is twelve point four sets it is
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probably about double but i think it's important for that what normal is is relatively low
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there was a a couple specimens in the study where they had this particular shape of the graph
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so the blue line demonstrates how the wrist is moving in a in its normal why
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and the reddish colour line is that of the prosthesis and the you can say as it moved backwards and forwards uh
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at the restarts here and as it moves through the the
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uh machine wick support pushes it through it comes back
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and buys it goes back around but there is on accomplice basements this little clunk
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across the and uh we've had extensive discussions with their engineering stuff about this
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an exact course of this is not known how are the more the engineering uh stuff tell
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us that i think this is a form of impinge meant that's occurring at the prosthesis
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so uh we'll discuss that a little bit to more data or lighten the discussion so with
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regard to that froze motion again we can say the the graphs are quite similar
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and this these images here demonstrate the change in centre
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rotation as the rest goes through the range of
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motion so we have the blue here is the normal wrist and this demonstrates the after plus
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the wrist so what's interesting to note that there is quite a degree of difference when it's looked
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in this this uh this method but it's important point out that this these uh millimetres
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so the amount of china does not massive but it it does demonstrate firstly the blue lines
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there is a considerable variation in the centre of rotation as the wrist guys for
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the range of motion and normal raised does not just move in one spot
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and saw it and we now and then a that is chinese in the centre of
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rotation as the the need goes through rounds motion the wrist does something similar
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exactly cells that at this point time i can't tell you but i think it's an interesting concept
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with the uh after plastic we can say it has this characteristic shied
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and exactly warren how this is at this point tom i don't know either but except
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asylum expected that the after plastic prosthesis would be almost like a single point
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with regard to the change in centre rotation of the normal wrist to this is the prosthesis
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we can say here that the average changes it passes dorsal by about five millimetres
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and as we know normal wrist the luna it's it's pretty well basically of
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the ball half of the the right you've to say a limit
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to say it was the prosthesis part definition is forced to be in
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the midline of the writing shop so therefore is a dorsal translation
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is a bit of distraction as i mentioned before and from a radio one ounce position the
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prosthesis is is a generally a pretty close to being exactly right from from that perspective
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so in discussion first of all the normal wrist i think this to homeowner learn with
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regard to the centre of rotation re some variability that translates backwards and forwards
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and uh i i think this with something will create a lot of interest uh as to how that
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works in my help explain some of the issues the centre rotation uh is uh you on
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the scrabble is that the the ready uh saris lunatic appetite articulation infecting now study we think it's
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a bit more distill and the normal wrist we know that there's a law degree of friction
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we uh i would what did the far that there's the f. a. agree variability
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with regard to have a little a lot and a display some because across the wrist
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and this may in part be related to have a prosthesis is
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just now actually putting slightly differently by even experienced surgeon
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but also the the this note that variations in the normal anatomy of the wrist which which may be part of it as well
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with regard to the centre rotation if we were so how can we use this information
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to maybe try and reproduce the wrist to mike and actually more an atomic
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the uh this is where the wrist was sitting and i think a lot of people do it like that
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but the manufacturer does provide this sort of a cutting the voice so it would be possible in say the
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prosthesis into the right is a little bit more which would actually help correct this interpretation of the prosthesis
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going on from from the yeah the um with regard to
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the thought that i just was advertised be sitting here and i thought this would
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be a small dot so really big the questions to what's different so
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we talked before about this with comfort manufactured brochure and this is how the the surgeon chose
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to put in and uh but basically you can say is gonna fear how old
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across the kappa tight and across the uh the film a couple but it might be
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because this articulation is not fused and of course even if it was
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even if it was lined refused to that at all the surgeon at time zero it
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it's actually still gonna be mobile so it's it's sort of a bit of a silly test in that regard but the
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point that one mike is it my swivel in an hour or got moved back for in full from that position
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i did actually take some of these flows topic images and i blew them up and my them entire screen of that
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i was not i would've categorically say that there was a a a dead
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and swinging all movement through that the prosthesis made a couple interface
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so it is this actually important well let downs uh this point i'm not sure of course
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so but we it maybe it's it is something of discussion but we can say here
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that uh the sender rotation we now is about the but whether there is some
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motion through this other point is i think it to be determined
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and whether it's actually important in clinical practised the noise
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then the other point is with regard to the use of the fusion and um one of the points it's interesting is
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that this is one of the images you can see how that staining to go towards the the dorsal age
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of the second met a couple whether that's important for some sort of infringement
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again i don't know but it's something that is worthy of discussion
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so that when we look at the clinical outcome there these are these are from the literature we can say
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these results from one at i. e. is so where where is this would make a kappa listening well
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all these images even at i. e. is doesn't look as the the couples listing at all
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that doesn't seem to be a clinical problem if the discussion is really all about what's happening with the radius
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and so it's interesting to say the bind one is good this is re absorption and what's
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interesting to say that this tends to uh become more skill roddick lotta normal bind
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not do a caller reversed her shoulder placements and i know
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that the internal impinge the concept looks exactly like
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that after a few years so actually my view is that this is actually what floor at work
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and this is a metal on metal prosthesis is not probably so it can't be probably with
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formally um air engineering staff told us about consent those impinge on the prosthesis
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and this is uh from the brochure by the manufacturer uh that that concern that this might be impinging here
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this my impinging here in our study we only talk the the prosthesis
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that twenty or thirty degrees i'm confident there is no infringement
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at the prosthesis uh interface all at the writing started in in this study
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finally going and limitations this is a bar mechanical study it's time zero in the calibrate model
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we using limited range of motion the the wrist is moved
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quite slow it's and an on physiological a velocity and
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we've not compared to any other prostheses this prosthesis it
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has beehive this why other prostheses maybe completely different
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so in conclusion um there are some changes in the centre of rotation should probably a little bit different
00:21:10
in the normal wrist and also the prostate wrist which it different to work certainly are expected
00:21:15
uh the resistance in uh in the prosthesis is probably that double that of normal
00:21:21
but that froze motion with his prosthesis so any of the other
00:21:24
rounds the motion is possible and appears to be basically symmetrical
00:21:28
i really don't think impinge wants an issue at this point time whether this is clinically relevant or not i don't know uh
00:21:35
but i think it's something that harm zero we should try to skip the process is best fitted as we can
00:21:40
this is very much supplement report and i think finally the role of
00:21:44
the hicks appalled at this sort of technology i think really does
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chimes the why that we think about some of these concepts that difficult to understand that this sort of technologies helped us thank you
