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This is an interesting topic which came up in another thread. I thought it deserved its own.
It started with this article in the daily mail
Quote:
Emma Supple, 42, is a podiatrist and podiatric surgeon, practising privately and on the NHS at Chase Farm Hospital, North London. She has three children, Lucy-Mary, eight, Arthur, six, and Dorothy, three, with her husband Ian Bishop-Laggett, who works in IT. Here, Emma explains why she underwent a new procedure to correct her flat feet - and why she wants her eldest daughter to do the same.
I was born with flat feet - in my case, it is a result of my foot anatomy, meaning my heel has a tendency to roll inwards. When my feet are in the air, I have beautiful arches, but as soon as I place any weight on them, they become flat as boards.
This is a common genetic condition which I inherited from my mother, who suffered dreadful bunions as a result. And, unfortunately, my eight-year-old daughter Lucy-Mary has inherited the problem from me.
The medical term for our condition is hyperpronation. Pronation - the rolling of the heel inwards - is the normal function of the foot, which allows us to quickly adapt out gait to walk on uneven surfaces.
But when there is excessive pronation of the foot - when it's too flexible - it causes excessive motion of the ankle and the heel bones. The results is the collapse of the natural space between these two bones, the sinus tarsi.
The foot then moves abnormally, causing the body's weight distribution and natural motion to go off-balance when standing and walking.
Naturally, feet should have a smooth heel-to-toe movement when walking. But with flat feet, the whole foot impacts on the floor simultaneously.
This makes it harder for the toe joints to flex and the added pressure is what causes pain. Over time, this can lead to serious problems with the ankles, knees, hips, back, neck and shoulders.
I had no idea I had a problem until I was 19 and visited the doctor about the knee pain I was experiencing. I was asked to pronate my foot and was astounded by how much movement there was.
Bizarrely, even though I was studying feet, I'd had no idea I was flat-footed as it had caused me no problems before. For years after, the medical college used X-rays of my feet to show what it's like to be severely flat-footed.
Having flat feet wasn't so much of a problem in the past, when we all walked on uneven surfaces and needed our feet to be more flexible. But now, practically all the surfaces we walk on are hard and flat. In addition, we tend to weigh more (which puts more pressure on the bones and joints) and live longer (which means we're walking around for a lot longer than in the past).
Once I was diagnosed, I was given special insoles to help correct the problem. I also started wearing shoes with a small heel (about 21/ 2in), which are usually the best option for someone who is flat-footed as they are naturally arched in a high-heel.
Ballet pumps or totally flat shoes are terrible if you have flat feet, as they give your feet no support. Walking on hard surfaces like sand is difficult too. On one occasion, in Spain, I ended up needing a piggy-back because my feet were so painful after trekking across a beach.
hypocure
* When standing, the inner part of the foot (the arch) should be raised off the ground. When there is a low arch or no arch, it is referred to as flat feet.
* In some, the arch flattens only when the foot is bearing weight and the foot may roll inwards, due to the collapse of space between the ankle and foot bones.
* In these cases, a stent can be inserted to give support, curing flat feet.
* Around one in five of the population is affected.
* It is normal for infants and young children to have flat feet. The arch develops between the ages of three and ten. The arch may never develop and flat feet can occur as a result of injury, arthritis, or disease.
I knew that, inevitably, the problem would get worse over time. Various drastic surgical options are available to correct flat feet, including lengthening the Achilles tendon and fusing various foot bones. But they are all major operations with a long recovery time.
As a working woman with young children, I simply couldn't afford to be off my feet for six months at a time. I decided to grin and bear it.
Then, in 2008, at the annual podiatric conference, I attended a lecture by an American surgeon called Mike Graham. He had invented a type of stent called a HyproCure which can be surgically inserted to cure flat feet.
The procedure is called arthroreresis. It involves opening up the foot canal and placing the stent between the foot and ankle bones. The titanium stent acts like a bolt, holding the gap open like a door wedge, so the bones stay in the correct position.
There are huge benefits over other procedures, as it can be done under local anaesthetic, the recovery time is short and it is reversible (the stent can be removed and the foot returned to its previous position).
I remember sitting in the audience, listening to Dr Graham's presentation-thinking this was the answer to my problems.
The operation was first developed for children - most anatomic problems like this are easier to correct before growing has finished. Lucy-Mary is already having problems because of her flat feet. She can't walk long distances without wearing insoles, and her feet and legs become fatigued as they don't have much support.
I instantly thought it might be good for her to have the operation too - so she need never end up with her granny's bunions. But I wanted to find out more.
In April 2008, I travelled to Detroit and trained to carry out the surgery myself, on cadavers. While there, I met more than 20 surgeons who were doing the procedure, in both the US and the UK.
On February 11, 2009 , I had the surgery myself on my right foot - my dominant leg. Within days, I could put my foot on the floor and within a week I was able to stand at a cooker and flip pancakes for my Brownie pack on Shrove Tuesday.
I spent five weeks heavily bandaged but in no pain at all. As soon as the bandages came off, I went dancing.
The stent should last for life, although nobody knows for certain because the long-term evidence and data are simply not there yet. I'm in good company, though - Dr Graham had the same surgery last week.
I'm hoping to have my other foot operated on this year and Lucy-Mary will have it in a few years' time. There is still a chance her problem could correct itself naturally.
I'm now performing the surgery on patients, as are other surgeons in the UK, and we're working to have stent surgery introduced into the NHS.
NICE, the National Institute for Clinical Excellence, has looked at the procedure and, provided you have informed consent and it is an appropriate choice, it is an accepted treatment that we hope will become more widely available in the near future. It's fantastic news for patients, who now have an alternative to major surgery.
Simon Said
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The question is, would you put your 8 year-old daughter forward for elective surgery?
And Dave Said
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Don't know about you but this surgery just looks wrong to me. Inserting a bolt into the mechanism to jam it up eh! sounds like a bodge job to me. Especially at the point of least mechanical advantage i.e. at the lever fulcrum where huge forces are required to resist opposite applied moments.
If your offside front car suspension unit was banging against the inner wing and instead of changing the damper/shock absorber or mainspring the mechanic jammed a bolt between the wishbone and the sub frame, I don't think you or the car would be very happy for long.
I wonder what happens at the interfaces when you run on uneven ground or jump off a low wall with this bolt inserted in the sinus tarsi.
Am I not understanding something here perhaps its a rubber trunion
I don't know enough about this operation to make definitive comment. I can see the sense in limiting the range of the STJ to limit the medial excursion of the ST Axis and thus make orthotics more effective.
That said, like Dave, I worry about the bone the stent is put into. We know the problems we get with bone on bone compression. Will bone on bolt compression cause problems also?
And can a stent inserted in a child's foot really "last for life?". And will the bone in which it is embedded?
Another concern for me is this bit
Quote:
# When standing, the inner part of the foot (the arch) should be raised off the ground. When there is a low arch or no arch, it is referred to as flat feet.
# In some, the arch flattens only when the foot is bearing weight and the foot may roll inwards, due to the collapse of space between the ankle and foot bones.
# In these cases, a stent can be inserted to give support, curing flat feet.
Is a "low arch" in static WB really "flat feet"? Is it abnormal?
Does anyone know if the Stent allows for any STJ pronation or not ? Is the STJ fixed in terms of pronation? If it does allow some pronation how much. Is this adjustable from patient to patient ? It brings up lots of questions
I have a feeling that this is another one of those looks great in the xrays so it must be great.
I went looking at the other threads and here whats Steve wrote to , see in red it kind of goes against the whole paper peice about Hypocure being a cure for "flat feet"
Quote:
Originally Posted by drsarbes
Hi Robert:
Looks like the Surgeon shortened/dorsiflexed the first ray even more than they had been preoperatively, causing not only additional forefoot varus but sub lesser met pain from the transfered weight bearing. Probably never had neuromas.
Some bunions NEVER hurt! Guess his preventive surgery didn't prevent much except a painless foot.
The hypocure (or any arthroereisis procedure) only decreases STJ eversion, it's not a cure for flat feet, especially if they have a short heel cord and marked FF varus.
Sounds like your surgeon has the Hammer/Nail syndrome.
Prior to any additional surgery I would get some Orthotic suggestions from the arena.
Here's how I see it: we have pronation moment about the STJ axis which, among other things determines the position of rotational equilibrium at the STJ. We don't like the position of rotational equilibrium that the STJ adopts as it's too pronated so we insert a bolt into the sinus tarsi. We now have a different equilibrium position but moments may have changed little; it depends how much the axis would have shifted from initial position of rotational equilibrium to new position of rotational equilibrium. So if the STJ was maximally pronated before and now the patient functions at a new end of range created by the bolt, then the residual pronation moment may have been slightly reduced but, there may still be residual moment = bone on bolt compression. And the patient is still max pronated.
Personally, I would not be going in the national press advocating this for 8 year-olds, but each to their own.
Here's how I see it: we have pronation moment about the STJ axis which, among other things determines the position of rotational equilibrium at the STJ. We don't like the position of rotational equilibrium that the STJ adopts as it's too pronated so we insert a bolt into the sinus tarsi. We now have a different equilibrium position but moments may have changed little; it depends how much the axis would have shifted from initial position of rotational equilibrium to new position of rotational equilibrium. So if the STJ was maximally pronated before and now the patient functions at a new end of range created by the bolt, then the residual pronation moment may have been slightly reduced but, there may still be residual moment = bone on bolt compression. And the patient is still max pronated.
Personally, I would not be going in the national press advocating this for 8 year-olds, but each to their own.
Very interesting stuff all round. I'm not going to claim to be a biomechanics guru or talk in moments or about rotational equilibrium. Bringing this back to very basic terms - which would I prefer - an insole or an arthroeresis? Insole for me, but that's personal preference to a point.
If I had thoroughly exhausted all conservative treatments such as orthoses and ankle supports, I may then consider this type of surgery. I adopt a similar decision making process for my patients. With any arthroeresis procedure there are potential complications. If a patient refuses conservative treatment, they are made aware of these potential complications prior to considering any surgery so they may make an informed choice (although I recognise issues around consent and practitioner/patient understanding of any procedure) whether they then consider the procedure to be appropriate.
Certainly it seems a less invasive procedure than other flatfoot surgery and offers many potential benefits when compared. I guess Steve has already commented on other factors governing success in flatfoot surgery so I'm not going to get into that other than to say that any one procedure such as this could not answer all flatfoot problems and needs to be taken in context of the individual presenting on the day and their pathology. In addition to this, would I do this procedure on my 8 year old child given that this particular design of arthroeresis has only been around for a couple of years? No. I've read all the 'anatomic design' advertorials from the company that produce the arthroeresis and I am hopeful that their claims ring true in the future, but until then I would be cautious to only use this type of surgery in those patients presenting with indications for having arthroeresis surgery having exhausted conservative treatment.
The subtalar arthroereisis procedure has been done for at least the past 35 years here in the States (Subotnick S: The subtalar joint lateral extra-articular arthroereisis: a preliminary report. JAPA, 64:701-711, 1974). I lectured on the biomechanics of the subtalar arthroereisis a few months ago at a surgical seminar in San Diego and it certainly has clinical application in selected patients since it basically "resets" the maximally pronated position of the subtalar joint to a less medially deviated STJ axis position. However it is not without problems. When I have some more time, I will post my lecture notes for those who are still interested.
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
it basically "resets" the maximally pronated position of the subtalar joint to a less medially deviated STJ axis position.
Nicely put, Kevin. That's what I was trying to say above. The issue arises when the tissues resisting the moments acting about the STJ's new axial position at max pronation in association with the stent are still forced to function in their pathological zones of stress, I guess at that point you use stent + orthoses.
The subtalar arthroereisis procedure has been done for at least the past 35 years here in the States (Subotnick S: The subtalar joint lateral extra-articular arthroereisis: a preliminary report. JAPA, 64:701-711, 1974). I lectured on the biomechanics of the subtalar arthroereisis a few months ago at a surgical seminar in San Diego and it certainly has clinical application in selected patients since it basically "resets" the maximally pronated position of the subtalar joint to a less medially deviated STJ axis position. However it is not without problems. When I have some more time, I will post my lecture notes for those who are still interested.
I would be
Dave
__________________
Descartes seems to consider here that beliefs formed by pure reasoning are less doubtful than those formed through perception.
The subtalar arthroereisis procedure has been done for at least the past 35 years here in the States (Subotnick S: The subtalar joint lateral extra-articular arthroereisis: a preliminary report. JAPA, 64:701-711, 1974). I lectured on the biomechanics of the subtalar arthroereisis a few months ago at a surgical seminar in San Diego and it certainly has clinical application in selected patients since it basically "resets" the maximally pronated position of the subtalar joint to a less medially deviated STJ axis position. However it is not without problems. When I have some more time, I will post my lecture notes for those who are still interested.
I would be cautious to only use this type of surgery in those patients presenting with indications for having arthroeresis surgery having exhausted conservative treatment.
Reply With Quote
That seems sensible. It strikes me that this, like any surgery, probably has its place, in which it will do much good, and areas where it should NOT be used, where it could do much harm! I'm certain its inventors are acutely aware of such, however it is a sad truth that once something like this is "out there", especially when it receives such glamorous and glowing reviews in the national press, it will eventually fall into the hands of somebody less careful.
I can think of a few patients in whom I would consider giving it a go. However the suggestion that it be used prophylactically in children with "low arches" chills me to the core! I look forward to a stream of parents with the cutting in their hands asking if THEIR 8 year old can have one.
It is a sad truth, IMO that whilst many surgeons master biomechanics and use it well, not all do and Podiatric and Orthopaedic surgery has its share of "all pronation bad" type folk. How long before surgeons have a crack at solving a problem which they believe to be caused by "overpronation" by whacking a stent in the ankle...
Hi Mike:
I'd be happy to upload some pre and post ops.
Can you give me a day? I've spend a lot of time uploading pics today - my nurse is about to throw something at me!!!!!!
I only take APs and Laterals for the implants.
Steve
PS
Apparently they are pushing the HYPOCURE device in various parts of the world, however, in the USA we call it a STJ Arthroereisis procedure, regardless of the make or model implant selected.
Kevin is correct in that these have been done in one form or another since the #10 blade was invented.
When I was a student we would fashion cone shaped implants out of blocks of silicone.
Steve
__________________
DrSArbes
Fellow American College of Foot & Ankle Surgeons
Board Certified Foot & Ankle Surgery, ABPS
Adjunct Professor OCPM
Green Bay, Wisconsin, USA
The subtalar arthroereisis procedure has been done for at least the past 35 years here in the States (Subotnick S: The subtalar joint lateral extra-articular arthroereisis: a preliminary report. JAPA, 64:701-711, 1974). I lectured on the biomechanics of the subtalar arthroereisis a few months ago at a surgical seminar in San Diego and it certainly has clinical application in selected patients since it basically "resets" the maximally pronated position of the subtalar joint to a less medially deviated STJ axis position. However it is not without problems. When I have some more time, I will post my lecture notes for those who are still interested.
I have started a new thread [more general in nature than this thread that is focused only on the recently released Hypoprocure Implant] regarding the biomechanics of all subtalar arthroereisis procedures, for those of you who are interested.
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
Hi Mike:
I'd be happy to upload some pre and post ops.
Can you give me a day? I've spend a lot of time uploading pics today - my nurse is about to throw something at me!!!!!!
I only take APs and Laterals for the implants.
Steve
PS
Apparently they are pushing the HYPOCURE device in various parts of the world, however, in the USA we call it a STJ Arthroereisis procedure, regardless of the make or model implant selected.
Kevin is correct in that these have been done in one form or another since the #10 blade was invented.
When I was a student we would fashion cone shaped implants out of blocks of silicone.
Steve
No stress on time when ever you can would be great to see, I guess your still a bit slow on your feet after the accident and can´t dodge flying objects as fast as you used too.
Kevin is correct in that these have been done in one form or another since the #10 blade was invented.
When I was a student we would fashion cone shaped implants out of blocks of silicone.
From a engineering point of view these shock attenuating devices seem like a better idea than a rigid bolt.
Dave
__________________
Descartes seems to consider here that beliefs formed by pure reasoning are less doubtful than those formed through perception.
From a engineering point of view these shock attenuating devices seem like a better idea than a rigid bolt.
Dave
Agreed, but if the subject still stands pronated end range motion (SPERM) and there is residual pronation moment, wouldn't the stent just compress and effectively become stiffer? In so doing the STJ will pronate further, leading to increased pronation moment as the axis medially deviates.
Agreed, but if the subject still stands pronated end range motion (SPERM) and there is residual pronation moment, wouldn't the stent just compress and effectively become stiffer?
True, but the load rate on the bone around the stent would be slower. Kinda the difference between a rubber door stop and a metal one. They both allow the door to reach the same point but one makes a thump and one makes a bang. Silicon sounds a better idea to me, but then what do I know.
True, but the load rate on the bone around the stent would be slower. Kinda the difference between a rubber door stop and a metal one. They both allow the door to reach the same point but one makes a thump and one makes a bang. Silicon sounds a better idea to me, but then what do I know.
Bone is visco-elastic. Faster loading = stiffer = greater capacity to store energy.
Agreed, but if the subject still stands pronated end range motion (SPERM) and there is residual pronation moment, wouldn't the stent just compress and effectively become stiffer? In so doing the STJ will pronate further, leading to increased pronation moment as the axis medially deviates.
The silicon or less stiff stent could be much larger and so attenuate force over a longer period of time and a greater range of motion but still have the same compression stiffness (or similar) at the same STJ rotation position.
Robert wrote
Quote:
True, but the load rate on the bone around the stent would be slower. Kinda the difference between a rubber door stop and a metal one. They both allow the door to reach the same point but one makes a thump and one makes a bang. Silicon sounds a better idea to me, but then what do I know.
Exactly (the former not the latter Robert)
Intuitively I agree with Robert but there is merit in Simon's argument too and needs thinking about. I would also add that the silicon stent would tend to deform to the shape of the accommodating surface and so potentially the surface pressure would be reduced relative to a more stiff interface. Generally it's the force per unit area that indicates the tendency to pain and abrasive / erosive wear and tear. Engineering types like to avoid spikes in the force/time integral as they tend to cause more damage (e.g. Force-Time Integral Predicts Lesion Size in Contractile Model Simulating Beating Heart - http://www.endosense.com/site/pdf/Cl..._%2011.pdf) I suppose someone must have design engineered the titanium bolt concept.
Dave
__________________
Descartes seems to consider here that beliefs formed by pure reasoning are less doubtful than those formed through perception.
The silicon or less stiff stent could be much larger and so attenuate force over a longer period of time and a greater range of motion but still have the same compression stiffness (or similar) at the same STJ rotation position.
Robert wrote
Exactly (the former not the latter Robert)
Intuitively I agree with Robert but there is merit in Simon's argument too and needs thinking about. I would also add that the silicon stent would tend to deform to the shape of the accommodating surface and so potentially the surface pressure would be reduced relative to a more stiff interface. Generally it's the force per unit area that indicates the tendency to pain and abrasive / erosive wear and tear.
Dave
Dave, Robert,
I generally agree with what has been written. However, other factors such as longevity of the implant will also be significant. A nice gradual deceleration toward end of range is a good idea, but if the silicon stent wears out in 10 years and needs to be replaced this is not so clever. Also, lets assume we use a metal bolt to achieve our initial aim, soft tissues should contract over time and thus be able to provide supination moment which will help to decelerate motion as the joint nears it's new end of range.
I generally agree with what has been written. However, other factors such as longevity of the implant will also be significant. A nice gradual deceleration toward end of range is a good idea, but if the silicon stent wears out in 10 years and needs to be replaced this is not so clever. Also, lets assume we use a metal bolt to achieve our initial aim, soft tissues should contract over time and thus be able to provide supination moment which will help to decelerate motion as the joint nears it's new end of range.
As always there are so many variables to consider, but considering wear, wouldn't it be better to replace the soft stent in 10 years than to have to remodel the bony surfaces, which might be damaged and worn by the hard stent even more quickly?
The soft tissues would contract with either type and this might be fine with the hard stent except that the surgeon is not in control of the maximum applied forces. Can the osseous surfaces withstand the force peak when doing high impact activities as well as they can with the soft stent. One would imagine there will always be a higher force peak with the titanium insert V's silicon.
Dave
__________________
Descartes seems to consider here that beliefs formed by pure reasoning are less doubtful than those formed through perception.
One thing that got me a little worried is would not the harder stent around the softer bone act a bit like a healed fracture, which may flex more outside the healed fracture and be more likely to develop stress at this point due to the difference in hardness. So then overtime the stent may come lose and not much bone left to work with.
Hope that makes sense.
Dave just wrote a new post which says almost the same thing but much better said while I was writing mine !!
Hi Mike:
Here are your pre and post ops on the last pediatric STJ MBA I did.
The pre op radiographs are about a year apart. THe post op a few months after the last pre op.
Steve
__________________
DrSArbes
Fellow American College of Foot & Ankle Surgeons
Board Certified Foot & Ankle Surgery, ABPS
Adjunct Professor OCPM
Green Bay, Wisconsin, USA
The Following User Says Thank You to drsarbes For This Useful Post:
Thanks for putting the x-rays up Steve, There does seem to be some change in Joint space between to pre and post op. Good see where the stent travels will study them more closely if my eyes allow it.
Not really sure where this fits but just saw this on Podiatry today about STJ arthroereisis. Some why, where and how to prevent complications type stuff which might interst some.
Biomechanics of Hyprocure Arthroesis
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