today basically is I’m going to try and
get over to you passion for engineering
obviously but I’m also going to try and
put across to you my passion for bone
because bone is a fantastic material if
we could just do this much for a
material that was like bone it would be
absolutely amazing now all this work I’m
going to be talking about is actually
done here in this lovely city of ours
stoke-on-trent and more importantly with
my good friend prof pete thomas an
orthopedic surgeon based at Stoke isn’t
he lovely there is one of our babies now
how did someone who is yes I’m not
scared to say this bullied at school
just for having a foreign sounding name
used to race lawnmowers used to do
amazing equations and computational
methods for designing power stations to
make sure they don’t shake themselves to
bits get to become a professor in
medical engineering and find out well
first of all its absolute chance this is
my door I was on summer duties one year
and a phone was ringing in an office now
summer duties basically means clearing
so there could be student so I answered
the phone wasn’t a student on the end
there was someone talking to me in a
language it sounded absolutely what I
understood and I thought I can help this
girl out and but actually you nothing
about broken bones orthopaedic but one
thing I did know is that bones break
they do and they break every day the
bone we’re going to be talking about is
the tibia my lovely assistant is
demonstrating you would call it the shin
and there’s what I prepared earlier as
you can tell it’s broken but I can hear
you now there you’re an engineer what do
you know about orthopedics well my
philosophy for engineering and
particularly engineering design is very
simple I have to know absolutely
everything about the area in which i’m
designing to produce a design that works
if I don’t then I’m afraid good there’s
no excuses you need to know it so I’ll
spread the last 25 years learning
orthopedics now you might be surprised
to know that actually there’s 430 people
per million
head of population per year across the
world who will need an operation to mend
a broken tibia and that’s that’s just
the fact the highest at risk are
basically young adult males probably
playing football probably riding a
motorbike are doing something just as
stupid unfortunately though if you’re
young and you’re female doesn’t mean
you’re immune you can still break a leg
but luckily for you bones have evolved
over millions of years to heal they do
it really really really well my job is
to design something that helps the bone
heal not gets in the way the long bone
we’re talking about tibia is a long bone
it hills by calles calles is another
wonderful think it’s nature’s glue think
of like a hot glue gun if you can
imagine a hot glue gun in your head over
the next bit you understand what I’m one
about the thing probably that you won’t
think about is that actually it’s got to
have movement well movement means this
the ends move together and it releases
callous and that callous builds up and
builds up until it actually comes to
halt that’s when the bone is stiff
enough that’s what it’s healed and
there’s one we’ve prepared earlier
notice the lump now on average it takes
about 18 weeks for activity to heal can
be as long as 24 can be as short as
eight and a half weeks but what I do can
tell you is if you smoke your delay it
by at least four weeks and you can stop
it all together there’s the cameraman he
smokes that’s his reason to stop now
what about that lump where your body
remodels itself continuously over your
whole life and the way it works is that
you have these little cells called
osteoclasts their natures diggers they
go around looking for bits of bone that
aren’t needed and they get rid of it
osteoblasts are the opposite they lay
down bone just like a builder where it’s
needed it all works under something
which is called Moore’s Law and it’s
very simple where a bone is too big
osteoclasts get rid of the bone and ship
it off somewhere else where a bone is
too small it lays it down and we end up
with an optimum solution if you’ve got a
small load you’ll have a small bone if
you’ve got a big load you’ll have a big
boat
this is one of the reasons why
astronauts have to exercise in space
because in space not only does no one
hear you scream but also there’s no
gravity and because there’s no gravity
there’s no load on the bones of those
osteocytes thinks it’s party time at the
buffet so if they don’t exercise when
they come back won’t be a pretty sight
let’s get back to mending tibias if
you’re unlucky enough to go to hospital
with a broken leg the first thing is
they’ll say is it a stable or an
unstable fracture a stable fracture is
basically one where if you load the ends
the ends come together and nothing very
much happens an unstable fracture has
got a more complex shape and if you load
it and the ends come together ping off
it goes in a different direction at one
leg ends up shorter than the other
there’s that example again stable
fractures you’ll seeing them in plastic
a stool over the place unstable
fractures need a bit more support they
need metal work and those an example
it’s an external fixator it’s called
external because it’s outside the body
and fix means it’s mending it the bit I
want you to look at is the bit in the
middle because that’s before we started
our work and we’re going to see that
again in a moment it’s got to come off
and the way most surgeons will do it is
they look at your x-rays they look at
they look at manipulating the fracture
unfortunately those are those methods
are pretty inaccurate which means that
the most common occurrence is someone
says come back in a few weeks you might
be ready then which to an engineer is
like a red rag to a bull it’s a bit like
saying I’ll turn on that nuclear power
station it hasn’t blown up by next week
it’s okay it’s going to work now I want
numbers so there was obviously room for
improvement now Peter and I soon
realized actually those fixators
performed two jobs and not very well so
let’s divide them into two the first job
is reduction that’s basically bringing
the bones back into alignment now you’re
probably imagining something really
sophisticated I did know it’s actually a
very large assistant pulling on
someone’s leg for about an hour and I’m
not joking so there was clearly
something there there it is there’s our
mechanical assistance we call it storm
because it’s this Stafford shear notice
where it’s been designed orthopedic
reduction machine
now what’s it done before and after it’s
not too difficult to see what change
we’ve made because the one that was done
with storm you can’t even see the
fracture site the other thing is is that
the fixator doesn’t need any joints
anymore because all in the other part
we’re not the only ones you like it
other people do then he trouble is I
think we must had too much to drink
because we just cannot remember what we
were laughing at now the second job they
have to do is it’s in the title it’s
fixed that’s how a little baby but it
hides a lot of complex stuff inside
there there’s an optimum environment for
callus formation not only that the
callus is formed by people walking
notice that they’ve got normal shoes on
a normal trousers in fact most patients
walk the next day after operation the
way it happens basically comes from if
you draw a graph of strength to weight
ratio anything that’s got a high
strength to weight ratio there’s too
much material will be up above spiders
webs are really good they’re down the
bottom that’s where the iOS would be not
piece of material is wasted same thing
goes if the patient’s going to wear it
you need to be functional scorpions
brilliant adapted not very pretty as far
as I’m concerned spectacles however
everyone has got to wear them you pick
them patients like iOS that’s still got
to come off we used to use really
difficult equipment to measure the
stiffness of the fracture accurately but
it was very time-consuming and
cumbersome so we built it into our
office itself if those pins don’t touch
the side when he manipulate it the
fractures healed if it does then it’s
not healed 400 patients and stoke have
been assessed with that now and it works
beautifully no wise no computers but
they still have to come back to clinic
now are they walking where they’re
supposed to or are they we don’t know
when they go home so we started
monitoring them at home there’s a little
thing collect the data and we end up
with the graph that looks like this at
the beginning not very much is going on
because it
at the end it’s tailing off because the
fractures healing but they still have to
come back to clinic to get the data one
we’re bagging on about this sixty
percent of clinics involved someone just
saying you’ll find come back in four
weeks they’re redundant be much better
if they don’t have to you could do that
on the telephone so we’ve started going
to Internet of Things technology there
it is on someone’s what it would look
like on someone’s leg and what it would
look like when someone’s walking it will
send the data up to a computer and that
computer will then send the data back to
the patient or the surgeon now if
nothing’s awry and everything is going
to plan does that patient have to come
back to clinic no they can be rung up
and said he’s going very well in fact
they could look at it themselves tada
sixty percent of clinics gone sixty
percent of clinics gone means that
people don’t have to take days off work
to take their friends or brothers or
sisters in the hospital sixty percent of
clinics gone means is less traffic less
traffic means is more parking less
traffic means there’s less co2 emission
and the number is enormous for a clinic
that’s the estimate for one clinic for
one year now I’ve gone full circle now
because at the beginning i was using
complex equations to model power
stations i now use those same equations
to model how fractures heal in the late
80s Early 90s actually went to an
esteemed panel or I proposed that we
could connect all the power stations
together in the world send the data to a
host computer and that host computer
would analyze all of that and better
predict what was going on I was laughed
out of the room they’ll went Sydney data
over the ether are you mad well if only
they could see me now boy am I glad I
answered that phone thank [Applause]