BRITISH BROADCASTING CORPORATION
RADIO SCIENCE UNIT
CASE NOTES
Programme 4. - Broken Bones听
听
听
RADIO 4
TUESDAY听 30/05/06 2100-2130
PRESENTER: MARK PORTER
REPORTER: CLAUDIA HAMMOND
CONTRIBUTORS:
DAVID MARSH
SAM SINGH
ROGER ATKINS
PETER GIANNOUDIS
PRODUCER: DEBORAH COHEN听
听听
NOT CHECKED AS BROADCAST
PORTER
Hello. Today's programme is all about broken bones - or fractures. I'll be finding out what happens when a bone breaks, how it heals itself, and what, if anything, we can do to speed up the process - a topical subject given the state of Wayne Rooney's right foot.
And I'll also be discovering how the humble cartwheel inspired a computer based method for fixing and straightening complicated fractures.
CLIP
I was out of hospital after a week and then it's just great because you can walk - well you have your crutches but you can walk around, you can move. Within a month, six weeks, less than it should have been I binned the crutches.
PORTER
More from Corinne later.
My guest today is David Marsh. He's professor of orthopaedics at University College London and based at the Royal National Orthopaedic Hospital at Stanmore.
David, perhaps we should start right at the beginning - the anatomy of a bone. What's bone made up of?
MARSH
Well if you think about it as a material to start with the key thing about it is that it's a composite material, it's got fibres in it which are made of collagen, which is the same stuff that makes skin and muscle and tendons and things, but sprinkled among those fibres it's got hydroxyapatites, which is a calcium containing mineral, very hard. And these are blended together intimately, so that what you end up with is a material which is both tough and stiff, very stiff and strong.
PORTER
How does a body try and repair a bone after it's fractured and what can go wrong?
MARSH
It starts with a blood clot, an inflammatory process, the inflammation somehow, we don't know how, miraculously stimulates proliferation and recruitment of stem cells into the site and you start getting healing tissue formed and then somehow because it's in a bone it knows to go down the road of making bone. So the cells that would make - the same sort of cells that would make a scar in an ordinary wound, in a bone they are able to differentiate down towards bone forming cells - osteoblasts - and they will actually regenerate bone, it's not just a repair process, it actually does regenerate original top quality bone.
PORTER
But it doesn't always go smoothly.
MARSH
No. If that healing process, for some reason, doesn't work which - it's in a minority but it's more common in the high energy injuries - then you get what we call either a delayed union, where it happens but only slowly, or a non-union where it isn't going to happen unless somebody operates on it.
PORTER
听And you start to worry at what stage - so how long would you ...?
MARSH
Well there isn't a - I don't believe there's a hard and fast answer to that, it depends on your appreciation of the injury, whereabouts in the body it is, but basically that's why you need people with experience - you need surgeons looking after these people. And if you get to the point where you think this is healing more slowly than it should, given what I know about the injury, then you begin to think about delayed union. If you begin to think this isn't going to heal at all then you're talking about non-union.
PORTER
Well a broken metatarsal is one type of fracture that's had more than its fair share of headlines in recent weeks. It's the bone that runs from the ankle to the toe, and footballer Wayne Rooney broke one in his right foot last month, prompting widespread speculation as to whether he will recover in time for the World Cup.
We sent Claudia Hammond to find out more from consultant orthopaedic surgeon Sam Singh, and his patient Dan who is recovering from his second metatarsal fracture.
DAN
I was on holiday in Israel and I think I was just walking around barefoot round the pool and I just whacked into something very hard, maybe a rock that was around, and after that I was in a lot of pain. I went to the hospital and they didn't diagnose there was anything wrong but I think subsequently it looks as though there was a stretch fracture, which healed up temporarily, but then about a month later I think I knocked it again while I was in the gym and that's caused a re-fracture, which is what's being wrapped up now.
SINGH
His is a fracture of the second metatarsal, near this end, and it's quite a common place for us to get something called the stress fracture. Now a stress fracture is caused either by direct blow or by overuse. The site of his could be from a direct blow, because he says he remembers whacking the foot against something hard originally whilst on holiday in Israel or it could be just from you know that's an incidental but the injuries are difficult to treat and therefore we've been quite aggressive from him and you'll note that I haven't let him walk, I've put him into a - I've given him crutches, I've kept him non weight bearing and put him in a full plaster, which goes all the way up to the knee.
HAMMOND
And why does it have to be a plaster that goes right up that far?
SINGH
The metatarsal's a part of the foot and the foot links obviously to the ankle and the principle of treating any fracture is that you want to immobilise the joint above and the joint below. Now the joint which has the most motion above is always the ankle joint, so if we put him in something that looks like a slipper it would still allow the ankle to move and that will actually cause - still cause movement, potentially at the fracture site.
HAMMOND
And do you think these sorts of injuries are getting more common or is it just that we all know what metatarsals are because of Beckham and Rooney and lots of others - Michael Owen did it earlier this year as well?
SINGH
Certainly they're picked up more often and that could be one of two reasons. I think they are becoming more frequent but also the methods we have to screen them and to test for them, such as MRI scan or bone scans or a CT scan, these tests have only been around for the last 15 to 20 years or at least more popular in the last 15 to 20 years and as a result probably that's why we're seeing more of them as well.
HAMMOND
And has it carried on hurting or once you had the plaster did it stop hurting?
DAN
No, that's the thing, as soon as the plaster goes in and you stop walking on it the pain goes away. So it doesn't feel like there's anything wrong anymore but obviously that's because I haven't been walking on it for the last four weeks.
HAMMOND
Yeah, so it's not got that weight on it anymore, yeah. And does everybody just say to you - Oh you've got - What's wrong with you foot? Oh the same as Rooney. - do they all say that, are you getting bored with that?
DAN
I am getting bored with that and people asking me if I'm going to be fit for the World Cup.
HAMMOND
And I bet they all think they're the first person to say it as well.
DAN
They do and it gets funnier every time.
SINGH
Okay, so what we're going to do now just going to take the plaster off. All that noise is from the - just like a vacuum, so it sucks away the plaster dust. This is a vibrating saw. Okay. [Indistinct words] [Sawing noise]
HAMMOND
That didn't hurt at all?
DAN
No, not at all. It was a strange sensation, it looks like it should hurt but it didn't hurt.
HAMMOND
So you're just cutting the - you've pulled it apart a bit ...
SINGH
Pulled it apart and now I'm just taking off the under cast padding. This is just cotton wool really.
HAMMOND
Oh so it's got nice soft padding inside.
SINGH
It's nice soft padding because you can't put the plaster directly on bone, on the leg, otherwise you get blisters. Okay ready to smell the freedom?
DAN
Yeah.
SINGH
Okay, here goes.
DAN
Oh that's great. It feels really light.
HAMMOND
Was that lovely - having that off there?
DAN
Yeah, it's a real relief because you're aware of it the whole time, there isn't a moment where you ...
HAMMOND
And I see itching your leg there.
DAN
Yeah.
HAMMOND
The first time you can do that.
DAN
Yeah, that's a relief. It's good, it feels fine.
SINGH
Does it?
DAN Yeah.
SINGH
You can bend your knee if you want when you walk. That helps.
DAN
Yeah. The sides feel a bit stiff, that's probably normal.
SINGH
Good news. To your x-ray. I think you can see you've had a very long fracture line going across there, okay, it's quite distinctly clear. Now I can see today that fracture line's resolved, you can see where the fracture was and you can also see there's evidence of bone [indistinct word], so that looks very good. Alright?
DAN
Yeah.
SINGH
I think we can probably say you're going to be absolutely fine. The only thing is we would like you to - I'm probably going to put you in another boot for a little while and let you walk again, okay?
DAN
Right.
SINGH
Is that alright?
DAN
Yeah, how long is that for?
SINGH
Say about two or three weeks. But what we'll do is I'll put you in this kind of short walker boot, okay, this little moon boot. I actually want to get this right because this is a re-fracture, it's not the first fracture you've had here.
HAMMOND
So recovery times seem to vary quite a lot and it seems to be quite hard to predict how long it takes.
SINGH
Yes it is hard to predict but we have a few rules that we follow in orthopaeds for what time certain types of bone take to heal and usually we say with a bone like a metatarsal we give it about six weeks.
HAMMOND
And sometimes they seem to take much longer don't they, I mean when Beckham did his it was predicted he'd be off for six to eight weeks and it was seven or something like that. But when Michael Owen did his they also said six to eight weeks and it took 17 weeks.
SINGH
And it can and you've got to remember it's not just a case of getting him to walk now that the bone has we think - he's okay he can walk around the room and if I asked him to go run a marathon now or play 90 minutes of soccer at a professional level he might be struggling. So there's still some recovery there.
PORTER
Sam Singh talking to Claudia Hammond .
David, let's move on to surgical intervention, that fractured metatarsal is a classic case of immobilisation in the plaster, leave the plaster on for a while, take it off and away you go. Why do surgeons need to get involved in so many different types of fracture?
MARSH
Well there'll be several reasons why you'd want to surgical fix a fracture rather than treating it in a plaster. One would be where you have a fracture that involves a joint, where the fracture runs into the adjacent joint, and the pieces of the bone at the joint's surface have moved out of place, you really want to get them back in alignment otherwise the cartilage will suffer and you'll get secondary osteoarthritis. So we would do an internal fixation there, usually with little screws.
PORTER
So your options for internal fixation are what - a screw or ...?
MARSH
The fundamental device that we use I'm afraid are screws and nails. Screws would be for compressing things together, the nails we use in the shaft if we want to simply splint the bone from the inside.
PORTER
So this might be a long bone that's displaced in the middle, the ends aren't in contact for instance?
MARSH
Absolutely, the mid-shaft fracture of a femur or a tibia or a humerus.
PORTER
You put the nail in from where - from one end of the bone and run it literally along the length?
MARSH
You run it along under x-ray control, usually beautifully minimally invasive these procedures, you don't actually expose the fracture site at all. You just pass it down under x-ray control and then what's remarkable - and then you have these interlocking screws which stop the bone rotating around the nail top and bottom and the patient can virtually get up and walk straight after that, the structural stability is immediately restored.
PORTER
So no plaster.
MARSH
Usually not. And the great advantage of that is that it leaves the joint above and below, which the plaster immobilises, it leaves them free so that you can immediately begin the rehabilitation.
PORTER
What about external fixation, I'm sure we've all seen people walking around with contraptions on their - normally on their lower leg below the knee, what's the difference - why do some people have to have an external fixator rather than internal plates and pins ...?
MARSH
The thing that makes you nervous when you're internally fixing a fracture is if the injury has already done a lot of damage to the soft tissues and then you come along with an operation which does further damage then you can leave the limb with so much accumulated damage that then the fracture won't heal so well. The thing about external fixation is that it minimises the intervention at the fracture site, you don't actually put any metal work anywhere near the fracture. You stick pins or wires into the bone above and the bone below and then you have an external scaffold which connects the two. And basically that means that you've held the bone as solidly as if you had internally fixed it but you haven't actually been anywhere near the actual fracture site. So we would use that in high energy injuries, typically a motorcyclist or industrial injury where a lot of soft tissue damage has been done.
PORTER
Well the Illizarov frame is a specialised type of external fixator. It was developed after the second world war by surgeon Gavril Abramovich Ilizarov for correcting, non healing, or poorly set fractures in soldiers. And he is said to have got the idea from a cartwheel.
In the case of an injured tibia - that's the major bone we've just been talking about connecting the knee to the ankle - imagine the rim of the cartwheel surrounding the calf, while metal wires - the spokes - pierce and fix the fragments of bone which form the hub of the wheel.
Connect together three such rings along the lower leg with adjustable screws that can be lengthened or shortened and you have an external fixator that can be used to gradually pull a displaced fracture into the desired position.
Corinne sustained a nasty fracture to her ankle when she slipped and fell.
CORINNE
The first consultant who came round said they'd fuse it because there were too many breaks. So I whinged a lot and then I met Mr Atkins who came round and said no he'd put a Ilizarov frame on. And it was a very traumatic experience but it was on before you knew and if was just a relief to know that you were going to walk again because the first option was that you'll always limp and I'm very active.
PORTER
When they described the frame to you how did they explain it?
CORINNE
Minimally. Very minimally, not a lot to be honest. It was just it will make you walk, so it's a good idea.
PORTER
We're going to be putting a frame on your leg and that's about it. So did they show you the frame before the operation?
CORINNE
No. I think that's probably a good idea because they are quite horrific to look at.
PORTER
So you woke up after the surgery.
CORINNE
I woke up screaming and they said 1 out of 10, I was going a hundred.
PORTER
Talking about your pain.
CORINNE
Yes. The pain level. And then after a couple of days it went down. I was out of hospital after a week and then it's just great because you can - well you have your crutches but you can walk around, you can move. Within a month, six weeks, less than it should have been, I binned the crutches.
PORTER
But what was it like actually wearing the frame on a day to day basis because I mean they are big aren't they, they're fairly cumbersome?
CORINNE
They're very cumbersome. The hardest one is sleeping because you have to prop your heel up so that the pressure isn't - you're not resting on the frame because it's a big circular thing around your leg and you have to support your thigh and your knee because the frame for me was from my knee to my foot, and your knee really starts to ache because it's unsupported. It did hurt originally because you have these massive pins going through your leg and the pins start ...
PORTER
Of course because the pins go from the frame and into the leg to the fragments of the bone. Yours were going straight through as well were they?
CORINNE
Yes because you have to stabilise the frame.
PORTER
And you have to keep those clean because I mean there's little wounds around each entry point.
CORINNE
That's a long job, sit there pouring stuff over it. And I had one that hit a nerve at the top of your leg, so that hurt the whole time.
PORTER
And presumably they had to be kept dry as well?
CORINNE
Yes, you're not allowed - that's plastic bags over your leg. But you get quite adept at it.
PORTER
Consultant Roger Atkins, from the Bristol Royal Infirmary, is the orthopaedic surgeon who looked after Corinne.
ATKINS
The operation is similar to the operation you would do if you were going to put a plate or a nail in. If anything the operation is more minor because all you're doing is making tiny little holes to put the wires through, whereas if you're going to put a nail down or a plate on you need to make a big cut in the leg. So the operation is more minor. The frames are quite painful for about 48 hours and then they settle down really normally to mild discomfort. The exception is if one of the pin sites gets infected and then it's like having a boil on your leg. The patient has to do pin site dressings and the dressings we use we put a clip - you see this red plastic clip - and these spongy dressings and the patient changes these every week and cleans the area, normally with just saline.
PORTER
You talk about infection being a problem with internal fixation when you've had a wound there and you've got a plate and screws there's foreign bodies in there but of course you've got a foreign body here as well with the pin and you've got a portal of entry for the bacterium, is infection a problem with this?
ATKINS
Infection of the pin sites - the small area of pin site in the skin - used to be a big problem until we started doing dressings like this, which were occlusive and compressed. We still do get pin site problems but they are not nearly as common as they used to be. A pin site infection is a minor local thing. If you put a plate on to a bone and that gets infected that is a very big infection and it's certainly limb threatening and it can be life threatening.
PORTER
So once the bones are fixed to as good a position as you can get them in at the time what you're then saying is because of the adjustability of these frames that you can actually almost perfect the healing of the bones, but how do you know how to make the necessary adjustments and who makes them?
ATKINS
Well you take x-rays and you measure the - what we call the deformity, which is the displacement. So in this fracture we've got here you can see that the lower end is probably turned outwards, if you look sideways on it's probably turned a little bit backwards and if you look here you can see that it's translated a little bit. So we would measure that on the x-rays, we then enter those parameters into a computer program, we tell the computer program what frame we've got on and where it's on the leg and the computer program produces a set of strut adjustments and the patient then adjusts the strut according to what the computer tells it to do. So you then see them a week or so later, take another x-ray and repeat the process.
PORTER
And those adjustments aren't just used to straighten up displaced fragments, the frame can also be used to pull and lengthen bones that have shortened after fracture. Jeanette Faulkner has been in a Ilizarov frame for four months to try and correct a shortening caused by a poor repair of a fractured tibia sustained in a crash in Zimbabwe 17 years ago. Her leg was re-broken and the frame used to stretch it, millimetre by millimetre, as it tried to heal.
FAULKNER
Basically you've got a strut with a number on and millimetres on the side of it and they give you a computer sheet, which is a reading for your daily movements, which are six which I've had. I did three in the morning, three in the evening.
PORTER
So basically you're using these struts at the side to stretch the frame which is stretching the bone in your shin. How much are you actually moving it each time - using a spanner presumably are you on the nuts?
FAULKNER
It would be one or two millimetres but some days on one strut you may not move that strut for that day and you'd move the other six or you'd move two and not - so it was done to correct how the bone was going to grow.
PORTER
And that's all ascertained by the computer, so all you do is follow the instructions and you come back to the clinic here for - they keep an eye on things?
FAULKNER
Every four weeks, it was every two weeks and then every four weeks after.
PORTER
And when it's likely to come off?
FAULKNER
I'm hoping fairly soon because the bone has grown tremendously and they've done really, really well, so I'm hoping it's very, very soon.
PORTER
Jeanette Faulkner in Roger Atkins' orthopaedic clinic at the Bristol Royal Infirmary.
You are listening to Case Notes, I'm Dr Mark Porter and I am discussing fractures with my guest orthopaedic surgeon David Marsh.
David, we've talked about the classic surgical interventions - the carpentry if you like - what about bone grafts, where do they come into it?
MARSH
Well the purpose of the fixation is just to hold the bone still while nature does the job of regenerating enough bone to bridge the fracture and reconstitute it. If for some reason that biology doesn't happen then you have to come in with some kind of a stimulus, a biological stimulus, to complement the mechanical intervention that you've made. And bone graft is the longest established biological stimulus that we know how to deliver. And what it basically consists of is taking a bit of cancellous bone, out of the pelvis usually, through a small incision and literally sprinkling it around ...
PORTER
So you crush it up?
MARSH
Yeah crunch it up and lay it around the fracture site, as if you were fertilising a - laying fertiliser around a plant. And so the active ingredients are probably most importantly all the growth factors, all the molecules, that are in bone marrow and cancellous bone but also probably the cells, the bone forming cells, that are in the bone graft.
PORTER
So you're not actually using the graft to crunch up and pack the wound, it's not used as a sort of cement to go in there, it literally is used to stimulate the existing bone to grow?
MARSH
There are circumstances where you use it to fill a gap - that's true - but it's not a permanent filling, you're really delivering these biological factors so that your body's stimulated to produce the bone that will definitively fill the gap.
PORTER
Well amongst those naturally occurring growth factors are bone morphogenetic proteins - or BMPs - they promote bone formation and healing after injury. And BMPs can now be produced synthetically and applied directly onto a fracture site during surgery. Professor Peter Giannoudis is an orthopaedic surgeon at St James' Infirmary in Leeds.
GIANNOUDIS
The two commercially available molecules - the BMP 2 and the BMP 7 - are - and these two molecules obviously they've been developed by two different biotechnological companies - are available to be used in the theatre environment. One is in a sponge kind of delivery system and the other one is in a powder, which you mix it and you apply it locally to the area where there is the defect in question.
PORTER
And what sort of defects are you using these products to help close?
GIANNOUDIS
Some in between one to four centimetres I think they can be used successfully. Above the four centimetres no one from the clinicians has actually attempted to use them in isolation.
PORTER
Can you give me an example of the sort of problem though that would result in a defect of that size?
GIANNOUDIS
For instance you can drive your motorcycle and you can have a crash with a car or you may lose control of the bike and you can have some kind of an impact, most of the energy will be absorbed by your tibia, this is the lower leg, and that will create some kind of fracture pattern which may well have a lot of fragmentation, the bone may well be exposed to the environment which means that it will lose vitality and therefore when the patient will come to the hospital for treatments all these fragments will have to be removed from the site of injury because they can serve as a source of infection from the different bacteria. And when you do so then you end up having a viable size of defect from let's say one centimetre up to four centimetres, sometimes it can be as much as 10-15 centimetres.
PORTER
But are the BMPs as effective as using bone grafts in these, for instance, let's look at the shin bone, in tibial fractures where there's a bit that's had to be removed or a bit missing?
GIANNOUDIS
Well they are as effective and the results which are available are as good as the results that we get with the [indistinct words] bone grafting technique. However, we have to take into account that when we take bone from the pelvis, let's say, this process involves an injury because you take a variable degree of bone graft from the pelvis and there is the risk of haematoma, infection, long time pain.
PORTER
It's more invasive to the patient.
GIANNOUDIS
It's more invasive and basically the last thing you want is to create another source of long term, let's say, pain, discomfort etc.
PORTER
Peter Giannoudis talking to me earlier.
David, could we not use these growth factors alongside the more conventional techniques that we were talking about earlier, the basic carpentry?
MARSH
Absolutely. I don't think you'd want to use it in every body, it's very expensive for a start and we don't know what - to what effects may eventually emerge, it is a powerful drug. And the bottom line is it's not necessary in many cases. But I think if you have a fracture which because of the nature of the injury or the nature of the patient you think that there's a high chance of delayed union then it has been shown quite unequivocally that things like BMP will improve the chances of that fracture healing first time.
PORTER
You mention they're expensive, how expensive?
MARSH
I think it's about 拢2,000 - between - around about 拢2,000 per shot. However, the good news is you only need to give it once, unlike a lot of expensive drugs.
PORTER
Presumably bone quality diminishes significantly as we get older, how does that affect your job as an orthopaedic surgeon?
MARSH
It's affecting it to a huge extent and an increasing extent. Already more than half of the fractures that we treat are fragility fractures, that's fractures in the elderly associated with osteoporosis. And also, of course, don't forget, with the tendency to fall.
PORTER
When you come to repair it presumably the reason why they were in there because the bones are fragile but they must be more difficult for you to put screws and plates in etc., in?
MARSH
Yeah it appears that osteoporotic bone is perfectly capable of healing itself, the trouble is that our normal techniques, which are designed for us to grip the bone with a metal device while it heals, that's where the problem arises because osteoporotic bone doesn't hold screws very well. So there's a danger that you'll lose the race - that the implant will come loose before the bone has actually managed to heal. So most of the implants that we use were designed for young fit people with strong bone and we need to do more research to develop things that work better in osteoporotic bone and we probably also need to do more work to find ways of biologically encouraging speeding up the healing of osteoporotic bone.
PORTER
There's a lot we can do to prevent osteoporosis medically and with lifestyle indeed in some cases, do you think we are aware enough about the dangers, the heralding signs of a fracture? I mean people say often - I get patients in who turn out to have osteoporosis and 10 years ago there's a good story of them slipping and fracturing their wrist, maybe we should have looked at them then?
MARSH
Well one thing we're now waking up to is the need for secondary prevention, everybody who comes in with a fracture, which is not associated with a significant, violent injury, the alarm bells should go off - this could be osteoporosis. And I would say to any patient who's had a low energy fracture they should be asking somebody - their GP or somebody - could I have osteoporosis and can we find out whether I have or I haven't. Because if you take the commonly available drugs that treat osteoporosis the chances of you having another fracture are reduced by half.
PORTER
David, we must leave it there. Professor David Marsh thank you very much.
Don't forget, if you have access to the net you can listen to the programme again by visiting our website bbc.co.uk/radio4
Next week's programme will be all about itching - in particular people who can't stop scratching even though they have otherwise seemingly normal skin. I'll be discovering why itching can be a sign of more sinister underlying health problems - particularly during pregnancy. And I will be finding out how cognitive behavioural therapy is being used to stop people scratching.
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