RE: active vs. inactive lifestyle after resurfacing?

August 16, 2003

Hi

You are asking all the right questions, but most of them cannot be

answered because resurf just hasn't been around long enough. The

very low number of failures of the BHR over the 12 or so years that

modern m-m resurf has been around is sufficient testimony to its

longevity in the medium term.

The thick-film lubrication you get with the large diameter

articulation means that wear rates are very, very low. McMinn tested

a BHR, lubricated naturally, with a huge weight loading and the

friction was negligible. Personally, I avoid too much impact

exercise, such as jogging, but I do not exclude it totally as

different kinds of loading are supposed to maintain bone density.

Nobody knows how long the bone cement will survive. It is subjected

mainly to compressive forces only, but if we are very unlucky, it may

degrade over two or three decades. If this occurs to the point of

failure, the worst case scenario might be your first THR at a

considerably more advanced age.

Despite the significant advances with new materials in THR's, which

must improve the longevity of them, resurfacing still has the

benefits over THR of:

Normal loading

Retention of the whole femur (minus a bit of reaming of the head)

with a normal blood supply.

Far less fat and marrow released into the bloodstream during the

op., reducing the likelihood of DVT and other problems.

Far less likelihood of dislocation.

Less restrictions.

My philosophy and the way I treat my resurf is to do everything I

need to do for my work and leisure, but try to do nothing to excess -

but hey, if you feel the need to sprint a million steps.......

Terry

> What activities after a resurfacing tend to shorten how long the

> resurfacing will last? Is it just the number of movements of the

> joint? Does the amount of pressure of these movements make a

> difference? For instance, would peddaling your legs a million times

> in a swimming pool while treading water, be less wear than jogging

a

> million steps and even less than sprinting a million steps?

>

> What eventually gives out? the bone cement? the metal parts?

>

> Can a modern resurfacing be expected to be as long lasting and

> durable as a THR? Why?

>

> A person who has a resurfacing, of course, does not want to do

> things that will substantially shorten the time to a revision.

> However, you do not want to unnecesarily eliminate activities

> because of lack of knowledge and being overcautious.

August 16, 2003

I have been seeking at least an understanding of this issue myself, but it

appears that detailed clinical information is not available to address the

delineations that you are asking. You will probably get the best perspective

by digging through the many resources and references on-line, but here is

some generalizations/observations that may be of interest.

You write:

" What activities after a resurfacing tend to shorten how long the

resurfacing will last? Is it just the number of movements of the

joint? Does the amount of pressure of these movements make a

difference? For instance, would peddaling your legs a million times

in a swimming pool while treading water, be less wear than jogging a

million steps and even less than sprinting a million steps? "

This is really a complicated question. The survivability of a resurfacing

job appears to be a function of different risk factors. One paper (by

Beaule) has a risk index for resurf patients under forty that assigns a

total of six points of risk (2 pts of femoral head cysts > 1 cm, 2 for

weight < 82 kg, one for previous surgery, and one for activity above 7 for

1-2 years using the UCLA scale. Thus activity, in the general sense, is a

risk factor, but to a lesser degree.

It appears that survivability is not significantly impacted by dislocation,

leaving loosening (mostly femoral) as the major issue. Unlike THR it is not

yet clear that wear (as measured by cobalt or chromium ion levels) particles

is the main risk factor in femoral loosening. What researchers seems to

measure is radiolucencies, when they get bad enough things loosen up and you

get symptoms. In one paper they did do a statistical analysis of things that

coupled to the appearance of radiolucencies in the metaphyseal stem and this

did not show any connection to the general level of activity. The factors

that did matter where gender, large cysts, height, and component size in

males. It may be the case that a lot of this really just relates to the

amount of surface area between the resurfaced femoral head and the head

component that can be cemented.

The common perspective would seem to be that the less impacting an exercise

is the safer it is, but for biological systems that isn't always true. If

mechanical wear of the moving surfaces isn't the issue that causes loosening

then maybe it doesn't matter. Then again the need for some level of surface

area in the cemented femoral head seems to suggest that impact forces are an

issue. I think this will take a while to understand in a quantitative way.

You wrote

What eventually gives out? the bone cement? the metal parts?

The femoral head seems to be progressing as the number one issue in modern

resurfacing but there is not a lot of data yet. The issue behind that will

be why does it losen (i.e. why do the lines appear?) The ability to provide

proper fixation of the femoral component may become an indicator in the

future.

You wrote

Can a modern resurfacing be expected to be as long lasting and

durable as a THR? Why?

I think this is a pretty clear " yes " . However large balls and new materials

for THR will have a significant impact on the longevity of THR. I really

don't see why a THR using something like oxidized zirconium, a 50 mm femoral

head, and a femoral stem designed to address the stress shielding couldn't

be as long lasting as a metal-metal resurfacing job. The resurfacing job

probably gives you more options in the future. Of course I don't think such

a product is in the field yet. I would really like to get a resufacing job

done with oxidized zirconium just to eliminate the issue of the ions.

A person who has a resurfacing, of course, does not want to do

things that will substantially shorten the time to a revision.

However, you do not want to unnecesarily eliminate activities

because of lack of knowledge and being overcautious.

Agreed. Life is full of risks, may God give you insight as you seek to

understand them.

active vs. inactive lifestyle after resurfacing?

What activities after a resurfacing tend to shorten how long the

resurfacing will last? Is it just the number of movements of the

joint? Does the amount of pressure of these movements make a

difference? For instance, would peddaling your legs a million times

in a swimming pool while treading water, be less wear than jogging a

million steps and even less than sprinting a million steps?

What eventually gives out? the bone cement? the metal parts?

Can a modern resurfacing be expected to be as long lasting and

durable as a THR? Why?

A person who has a resurfacing, of course, does not want to do

things that will substantially shorten the time to a revision.

However, you do not want to unnecesarily eliminate activities

because of lack of knowledge and being overcautious.

August 17, 2003

Hi,

From my readings about the materials used, a normal human being would have

to

do a great deal to ever wear away the surfaces of the m/m prothesis........

I have seen knee's prothesis bits with plastic that didn't take much but

that had a lot to do with misplacement which we simply will not get.

It is very important for continued bone health that the femur gets to have

all the usual work that it could be expected to get in a normal

body........... Mine was starting to show bone loss because of the fused hip

I had for 35 years - but the 6 month xray showed a considerable improvement

So just the small bit of weight placement walking etc I

had done until then, had obviously helped. This is without what the rest of

the body gains in a bit of walking exercise etc.

I get a lot of my extra exercise swimming and doing just as you say -

jogging in water......... but this is mainly because my back is a total mess

and will take me out long before the hip will. Which highlights the

difficulty really with any studies.......... where on earth will you get

several identical people and subject them to different things and see what

happens over a long period of time............. some may well get run over

by a bus or overtaken by heart etc problems long before any results could be

found re their hips.......... for our genetic structure, general luck with

life and state of health will have so much interplay here.

And if you want to start comparing THR's v Resurface wear etc, you have a

very big difference that makes nonsense of any real chance of having results

that are meaningful i.e. different way it is attached to bone, different

materials etc. And if you want to see the one major difference between the 2

prothesis just take a tour of Totallyhip and see discussions about

dislocations/restrictions.........and decide for yourself which you want.

All points to you needing to have some understanding of the potential

possibilities and to just get on with life.......... for it would be a

terrible thing to guard your hip with constant paranoia, not doing things

you really enjoyed, and then be caught in a car accident with a drunk one

night............. Well that is my take on it........

Edith

> What activities after a resurfacing tend to shorten how long the

> resurfacing will last? Is it just the number of movements of the

> joint? Does the amount of pressure of these movements make a

> difference? For instance, would peddaling your legs a million times

> in a swimming pool while treading water, be less wear than jogging a

> million steps and even less than sprinting a million steps?

>

> What eventually gives out? the bone cement? the metal parts?

>

> Can a modern resurfacing be expected to be as long lasting and

> durable as a THR? Why?

>

> A person who has a resurfacing, of course, does not want to do

> things that will substantially shorten the time to a revision.

> However, you do not want to unnecesarily eliminate activities

> because of lack of knowledge and being overcautious.

August 19, 2003

In a message dated 8/19/2003 10:26:45 AM Pacific Daylight Time,

david.selvey@... writes:

> My main concern is that we are at risk of making the same mistake that we

> have done before. This operation seems like a brilliant operation and so we

> rapidly expand the group of patients suitable to have it. We expand the

> indications faster than the research is created. This is a mistake that was

> made with unicompartmetal knees in the UK. Before long everybody was doing

> this operation on all different types of patients. Soon the group of

> patients that it was not suitable for started to fail. Suddenly the

> operation had a bad name and most people stopped doing it. Then they went

> back to the drawing board - identified who it actually was suitable for and

> now it has a good name again. The whole process has taken more than a

> decade.

>

Thank you for your excellent insights. Points all well taken. The reason I

highlight the above is that my US surgeon who supported my travel to the UK for

Ronan Treacy to resurface my hips made exactly this argument when I asked him

why he wouldn't think about performing the surgery himself given my excellent

results. Thank you for articulating (excuse the pun) this.

All the resurfacing surgeons I know of do caution against high impact

activities, and I agree that the danger is we'll feel so good after surgery that

we'll forget ourselves and do some damage.

Watch out, y'all.

Des Tuck

In California, dreaming of my next feat

August 19, 2003

Forgive me if I am an interloper into your group. I am an orthopaedic

surgeon in the UK. I actually specialise in shoulder surgery and I have at

present two completely normal hips. I realise the group is for people who

have or are having surface replacement but came across your group while

doing research for my 73 year old father in law who just had a surface

replacement. I am fascinated by the level of research that many of you have

done into this subject and have found your information very informative.

As a theoretical concept the surface replacement is brilliant. I strongly

believe that life is for living and you should live life now, not limp

around for 10 years until you are old enough to have a THR. I do however

have some concerns. (I am sure many or most of you have heard that before)

My main concern is that we are at risk of making the same mistake that we

have done before. This operation seems like a brilliant operation and so we

rapidly expand the group of patients suitable to have it. We expand the

indications faster than the research is created. This is a mistake that was

made with unicompartmetal knees in the UK. Before long everybody was doing

this operation on all different types of patients. Soon the group of

patients that it was not suitable for started to fail. Suddenly the

operation had a bad name and most people stopped doing it. Then they went

back to the drawing board - identified who it actually was suitable for and

now it has a good name again. The whole process has taken more than a

decade.

Although this implant is more stable than a THR and although it has no poly

debri the increased surface contact between the head and cup (As apposed to

a 22 - 28mm head in a THR) may well bring new problems. We dont know yet -

I certainly hope not.

The other thing that I havent had an answer to is although we preserve more

femur and therefor revising the femur is easy, we now take more acetabulum

because the cup is much bigger than traditional THR acetabulae (Because the

head is bigger). This may not be an issue because the revision surgeon can

rebuild bone on the acetabular side easier than on the femoral side, but

what if the femoral component fails, you go to convert to a THR but the Cup

is well fixed. How easy will it be to remove the large cup witout doing

some major excavatiuon of bone on the acetaular side.

I would recomment that anyone having this operation should continue to

respect that we cannot reproduce anything as resistant or maleable as bone

or cartialge.

Although it is necessary to stimulate bone to increase it strength, over

stimulating bone can equally cause " resortion " of the bone. The differences

between bone and metal are so massive that high impact loading could result

in lysis rather than stimulation of bone. Until we know differently I would

be wary of carrying out high impact activities.

A million cycles in a pool should theoretically not be a problem. One of

the theoretical beauties of a metal/metal surface is that it will " repolish "

itself and any metal debri will not trigger a granuloma formation the way

polyethylene will.

..

Rememebr If you are having this operation because you have severe pain on a

day to day bases but are too young for THR then thank your lucky stars there

is an operation that can take you pain away. But until we know diffrently

treat your new hip with respect. If it will allow you to become active

again so that you can keep your bones and the rest of your body healthy that

is great but remember that you no longer have cartialge lining your joints.

If you are planning to have this operation because you cant play rugby or

some other hig himpact sport any more then maybe you should think again.

August 19, 2003

The other thing that I haven't had an answer to is although we preserve more

femur and therefor revising the femur is easy, we now take more acetabulum

because the cup is much bigger than traditional THR acetabulae (Because the

head is bigger). This may not be an issue because the revision surgeon can

rebuild bone on the acetabular side easier than on the femoral side, but

what if the femoral component fails, you go to convert to a THR but the Cup

is well fixed. How easy will it be to remove the large cup witout doing

some major excavatiuon of bone on the acetaular side.

To the best of my understanding, if the femoral side should fail, and a THR

becomes necessary, then the acetabular side can remain as is. It would

then be a converted to a MOM THR using matching parts. I also think the

acetabular side has a longer lifespan? Anyone else know?

Thanks for the rest of your post! It was supportive and informative.

Lois

C+ 3/27/03 Dr. Mont

August 19, 2003

Hi ,

Welcome to our group! I for one, welcome doctors to this group because its a

way for us to increase our knowledge base from those working in the profession.

I'm new to this group myself and have recently been diagnosed with AVN Ficat

Stage 1 in both hips at age 36. At this point, my pain is very minimal and I

have some time to decide what course of action I should take. I joined this

group because the OS who diagnosed me told me I needed to get THR in both hips

and didn't offer me any other alternatives. I'm not a rugby player, skydiver,

or bungee jumper, but this seemed a little extreme for someone of my youth,

considering I'd most likely outlive my new hips and 2-3 revisions if I had any

bone stock left over at the end of all this. Resurfacing seemed like a logical

solution for me.

I couldn't help notice your concern about the cavity the resurfacing devise

would leave on the acetabulum side. I'm not sure if you know about the

proceedure called " hemiresufacing " but this is a proceedure where they resuface

the femoral side only and then put it back into your own natural acetabulum.

This is only used with those who, like myself, have unaffected cartilage. If I

decide to go with the Conserve Plus system, then should I need a total hip

replacement, all the parts are interchangable. The Conserve Total Hip

Replacement with BFH (big femoral head), as far as I know, uses the same size

femoral head as is used in the Conserve Plus resurfacing. Therefore, I assume

that the acetabulum that is already oversided from the previous resurfacing,

would work with the new THR.

If anyone knows otherwise, I'd welcome the correction if I'm misinformed on

this.

Thank you,

Craig

Boca Raton, FL

>

> Date: 2003/08/19 Tue PM 01:23:23 EDT

> To: <surfacehippy >

> Subject: RE: active vs. inactive lifestyle after resurfacing?

>

August 19, 2003

I have heard the same thing on this, Lois.

>

> Date: 2003/08/19 Tue PM 01:53:37 EDT

> To: <surfacehippy >

> Subject: RE: active vs. inactive lifestyle after resurfacing?

>

August 19, 2003

Dear Des thanks for your reply.

I actually operate out of the same hospital as Rolan Tracey in Droitwich.

This is one of the hospitals he works at. Did you have your procedure in

Droitwich.

There are more and more surgeons doing this in the UK.

Cheers

Re: active vs. inactive lifestyle after

resurfacing?

In a message dated 8/19/2003 10:26:45 AM Pacific Daylight Time,

david.selvey@... writes:

> My main concern is that we are at risk of making the same mistake that

we

> have done before. This operation seems like a brilliant operation and

so we

> rapidly expand the group of patients suitable to have it. We expand the

> indications faster than the research is created. This is a mistake that

was

> made with unicompartmetal knees in the UK. Before long everybody was

doing

> this operation on all different types of patients. Soon the group of

> patients that it was not suitable for started to fail. Suddenly the

> operation had a bad name and most people stopped doing it. Then they

went

> back to the drawing board - identified who it actually was suitable for

and

> now it has a good name again. The whole process has taken more than a

> decade.

>

Thank you for your excellent insights. Points all well taken. The reason I

highlight the above is that my US surgeon who supported my travel to the

UK for

Ronan Treacy to resurface my hips made exactly this argument when I asked

him

why he wouldn't think about performing the surgery himself given my

excellent

results. Thank you for articulating (excuse the pun) this.

All the resurfacing surgeons I know of do caution against high impact

activities, and I agree that the danger is we'll feel so good after

surgery that

we'll forget ourselves and do some damage.

Watch out, y'all.

Des Tuck

In California, dreaming of my next feat

August 19, 2003

Thanks for your explanation - That makes perfect sense.

RE: active vs. inactive lifestyle after

resurfacing?

The other thing that I haven't had an answer to is although we preserve

more

femur and therefor revising the femur is easy, we now take more acetabulum

because the cup is much bigger than traditional THR acetabulae (Because

the

head is bigger). This may not be an issue because the revision surgeon

can

rebuild bone on the acetabular side easier than on the femoral side, but

what if the femoral component fails, you go to convert to a THR but the

Cup

is well fixed. How easy will it be to remove the large cup witout doing

some major excavatiuon of bone on the acetaular side.

To the best of my understanding, if the femoral side should fail, and a

THR

becomes necessary, then the acetabular side can remain as is. It would

then be a converted to a MOM THR using matching parts. I also think the

acetabular side has a longer lifespan? Anyone else know?

Thanks for the rest of your post! It was supportive and informative.

Lois

C+ 3/27/03 Dr. Mont

August 19, 2003

Thanks for the many responses I have had. I certainly have been educated.

(I thought it was supposed to be the other way around). I have not heard of

doing a hemi surface replacement in the hip. I do however do this routinely

for my shoulder replacements. The soulder joint however is a very different

animal. However as I have now been informed there is not necesasrily a need

to avoid doing the acetabulum because the cup is in fact not any bigger

than with a THR because of the absence of a polyethylene liner, and in

addition, as as been pointeed out to me, should a THR be needed then a liner

could simply be locked into the cup without any need to remove the cup.

This has certainly answered my unanswered question.

On your AVN situation I would say that I have seen many patients

(Particularly in South Africa where I did a lot of my training) who have

quite marked AVN and do not necessarily have a corresponding amount of pain.

A Fikat and Arlet grade 1 is a very early stage AVN and you may never

progress any further than that. Even if you do your pain may not parallel

the progression so with a bit of luck your concern about what surgery to

have may remain theoretical.

Regards

----[ Selvey] . -Original Message-----

From: jcb561@...

Sent: 19 August 2003 18:58

To: surfacehippy

Subject: Re: RE: active vs. inactive lifestyle after

resurfacing?

Hi ,

Welcome to our group! I for one, welcome doctors to this group because

its a way for us to increase our knowledge base from those working in the

profession. I'm new to this group myself and have recently been diagnosed

with AVN Ficat Stage 1 in both hips at age 36. At this point, my pain is

very minimal and I have some time to decide what course of action I should

take. I joined this group because the OS who diagnosed me told me I needed

to get THR in both hips and didn't offer me any other alternatives. I'm not

a rugby player, skydiver, or bungee jumper, but this seemed a little extreme

for someone of my youth, considering I'd most likely outlive my new hips and

2-3 revisions if I had any bone stock left over at the end of all this.

Resurfacing seemed like a logical solution for me.

I couldn't help notice your concern about the cavity the resurfacing

devise would leave on the acetabulum side. I'm not sure if you know about

the proceedure called " hemiresufacing " but this is a proceedure where they

resuface the femoral side only and then put it back into your own natural

acetabulum. This is only used with those who, like myself, have unaffected

cartilage. If I decide to go with the Conserve Plus system, then should I

need a total hip replacement, all the parts are interchangable. The

Conserve Total Hip Replacement with BFH (big femoral head), as far as I

know, uses the same size femoral head as is used in the Conserve Plus

resurfacing. Therefore, I assume that the acetabulum that is already

oversided from the previous resurfacing, would work with the new THR.

If anyone knows otherwise, I'd welcome the correction if I'm misinformed

on this.

Thank you,

Craig

Boca Raton, FL

>

> Date: 2003/08/19 Tue PM 01:23:23 EDT

> To: <surfacehippy >

> Subject: RE: active vs. inactive lifestyle after

resurfacing?

>

August 19, 2003

,

I appreciate the issues you bring up. I am one of the people

contemplating resurfacing not because my day to day has become unmanageable

but due to the inability to be engaged in active sports (hiking, biking,

running, soccer/futbol). The medical community does not yet seem to have a

sense of what levels of activity are " reasonable " and I guess a number of us

are pondering the trade offs in lifestyle vs. the risks of accelerating the

failure of the resurfacing job. There is also a need to collect data in some

controlled fashion.

What would be helpful is some level of feedback that would provide

insight as to how activity impacts prosthesis. Perhaps the measurement of

ion levels, perhaps observing lines in x-rays. However with new procedures

we may not know what to look for.

I would like to understand why the larger head size might be an issue.

From what I have read so far the large size helps in both stability and in

generating a " thick fluid flim " between the articulating surfaces -- which

should reduce wear/debri -- are there other risk factors that it introduces?

Another question that someone may know but that I have not seen a reference

too -- is the acetabulae cup (in general) actually larger or does the thiner

metal surfaces simply allow a larger head? The Corin resurfacing cup comes

in sizes from 46-62 mm. The Stryker cup for 28-36 mm THR alunima heads range

from 46-68 mm.

I am more concerned about the impact of activity on the fixation of the

femoral head over time....

RE: active vs. inactive lifestyle after

resurfacing?

Forgive me if I am an interloper into your group. I am an orthopaedic

surgeon in the UK. I actually specialise in shoulder surgery and I have

at

present two completely normal hips. I realise the group is for people who

have or are having surface replacement but came across your group while

doing research for my 73 year old father in law who just had a surface

replacement. I am fascinated by the level of research that many of you

have

done into this subject and have found your information very informative.

As a theoretical concept the surface replacement is brilliant. I strongly

believe that life is for living and you should live life now, not limp

around for 10 years until you are old enough to have a THR. I do however

have some concerns. (I am sure many or most of you have heard that

before)

My main concern is that we are at risk of making the same mistake that we

have done before. This operation seems like a brilliant operation and so

we

rapidly expand the group of patients suitable to have it. We expand the

indications faster than the research is created. This is a mistake that

was

made with unicompartmetal knees in the UK. Before long everybody was

doing

this operation on all different types of patients. Soon the group of

patients that it was not suitable for started to fail. Suddenly the

operation had a bad name and most people stopped doing it. Then they went

back to the drawing board - identified who it actually was suitable for

and

now it has a good name again. The whole process has taken more than a

decade.

Although this implant is more stable than a THR and although it has no

poly

debri the increased surface contact between the head and cup (As apposed

to

a 22 - 28mm head in a THR) may well bring new problems. We dont know

yet -

I certainly hope not.

The other thing that I havent had an answer to is although we preserve

more

femur and therefor revising the femur is easy, we now take more acetabulum

because the cup is much bigger than traditional THR acetabulae (Because

the

head is bigger). This may not be an issue because the revision surgeon

can

rebuild bone on the acetabular side easier than on the femoral side, but

what if the femoral component fails, you go to convert to a THR but the

Cup

is well fixed. How easy will it be to remove the large cup witout doing

some major excavatiuon of bone on the acetaular side.

I would recomment that anyone having this operation should continue to

respect that we cannot reproduce anything as resistant or maleable as bone

or cartialge.

Although it is necessary to stimulate bone to increase it strength, over

stimulating bone can equally cause " resortion " of the bone. The

differences

between bone and metal are so massive that high impact loading could

result

in lysis rather than stimulation of bone. Until we know differently I

would

be wary of carrying out high impact activities.

A million cycles in a pool should theoretically not be a problem. One of

the theoretical beauties of a metal/metal surface is that it will

" repolish "

itself and any metal debri will not trigger a granuloma formation the way

polyethylene will.

.

Rememebr If you are having this operation because you have severe pain on

a

day to day bases but are too young for THR then thank your lucky stars

there

is an operation that can take you pain away. But until we know

diffrently

treat your new hip with respect. If it will allow you to become active

again so that you can keep your bones and the rest of your body healthy

that

is great but remember that you no longer have cartialge lining your

joints.

If you are planning to have this operation because you cant play rugby or

some other hig himpact sport any more then maybe you should think again.

August 19, 2003

From what I can gather, the hemi resurfacing seems more popular than

the total resurfacing in the United States, but dont know why In

fact, for some reason some medical insurance companies will only

cover a hemi and not a total.

The logical progression would seem to be a hemi, followed by a total

and a replacment after all else fails.

> Thanks for the many responses I have had. I certainly have been

educated.

> (I thought it was supposed to be the other way around). I have not

heard of

> doing a hemi surface replacement in the hip. I do however do this

routinely

> for my shoulder replacements. The soulder joint however is a very

different

> animal. However as I have now been informed there is not

necesasrily a need

> to avoid doing the acetabulum because the cup is in fact not any

bigger

> than with a THR because of the absence of a polyethylene liner, and

in

> addition, as as been pointeed out to me, should a THR be needed

then a liner

> could simply be locked into the cup without any need to remove the

cup.

>

> This has certainly answered my unanswered question.

>

> On your AVN situation I would say that I have seen many patients

> (Particularly in South Africa where I did a lot of my training) who

have

> quite marked AVN and do not necessarily have a corresponding amount

of pain.

> A Fikat and Arlet grade 1 is a very early stage AVN and you may

never

> progress any further than that. Even if you do your pain may not

parallel

> the progression so with a bit of luck your concern about what

surgery to

> have may remain theoretical.

>

> Regards

>

> ----[ Selvey] . -Original Message-----

> From: jcb561@b... [mailto:jcb561@b...]

> Sent: 19 August 2003 18:58

> To: surfacehippy

> Subject: Re: RE: active vs. inactive lifestyle

after

> resurfacing?

>

> Hi ,

> Welcome to our group! I for one, welcome doctors to this group

because

> its a way for us to increase our knowledge base from those working

in the

> profession. I'm new to this group myself and have recently been

diagnosed

> with AVN Ficat Stage 1 in both hips at age 36. At this point, my

pain is

> very minimal and I have some time to decide what course of action I

should

> take. I joined this group because the OS who diagnosed me told me

I needed

> to get THR in both hips and didn't offer me any other

alternatives. I'm not

> a rugby player, skydiver, or bungee jumper, but this seemed a

little extreme

> for someone of my youth, considering I'd most likely outlive my new

hips and

> 2-3 revisions if I had any bone stock left over at the end of all

this.

> Resurfacing seemed like a logical solution for me.

> I couldn't help notice your concern about the cavity the

resurfacing

> devise would leave on the acetabulum side. I'm not sure if you

know about

> the proceedure called " hemiresufacing " but this is a proceedure

where they

> resuface the femoral side only and then put it back into your own

natural

> acetabulum. This is only used with those who, like myself, have

unaffected

> cartilage. If I decide to go with the Conserve Plus system, then

should I

> need a total hip replacement, all the parts are interchangable. The

> Conserve Total Hip Replacement with BFH (big femoral head), as far

as I

> know, uses the same size femoral head as is used in the Conserve

Plus

> resurfacing. Therefore, I assume that the acetabulum that is

already

> oversided from the previous resurfacing, would work with the new

THR.

> If anyone knows otherwise, I'd welcome the correction if I'm

misinformed

> on this.

> Thank you,

> Craig

> Boca Raton, FL

> >

> > From: " Selvey " <david.selvey@b...>

> > Date: 2003/08/19 Tue PM 01:23:23 EDT

> > To: <surfacehippy >

> > Subject: RE: active vs. inactive lifestyle after

> resurfacing?

> >

>

August 20, 2003

It may be as simple as finances. A Hemi " any thing " is a much easier

operation and therefore probably costs the insurance company a lot less.

We do hemi replacements after fractures in the elderly where the femoral

head is essentially doomed to AVN because of the fracture location. In that

situation however these patients usually have completely normal hip joints

prior to their fracture. You dont need to replace their acetabulum because

it is normal.

In most individuals who require surface replacemtns, the acetabulum wear is

likely to match the femoral wear and so a hemi may not be an option. Having

said that most surface replacements I do in the shoulder are hemi's and the

" cup " side is usually fairly worn out but once you eliminate the bone on

bone contact you relieve much of their pain. Although the shoulder is

different to the hip, there is still a great deal of weight bearing through

the shoulder joint because of the lever arm effects in lifting you arm to

shoulder height.

[ Selvey] Re: active vs. inactive lifestyle after resurfacing?

August 20, 2003

I think that some of the " high impact " sports you are talking about would

probably fall into my acceptable category. ie hiking, cycling , but the

running football would make me nervous. Gut feeling only - no research

available. If you are putting an uncemented component into bone then you

rely on bony " intergrowth " to the back surface of your impalnt. If you over

stress that interface with jarring impact you could potentially cause micro

fracture at the interface and interfere with the " bond " between the two

interfaces. This could ultimately give rise to loosening.

Regarding your reference to the size of acetabulum I gather the fact that

the acetabulum has no poly liner means that the outer shell is in fact not

significantly bigger than that for a THR.

RE: active vs. inactive lifestyle after

resurfacing?

Forgive me if I am an interloper into your group. I am an orthopaedic

surgeon in the UK. I actually specialise in shoulder surgery and I have

at

present two completely normal hips. I realise the group is for people

who

have or are having surface replacement but came across your group while

doing research for my 73 year old father in law who just had a surface

replacement. I am fascinated by the level of research that many of you

have

done into this subject and have found your information very

informative.

As a theoretical concept the surface replacement is brilliant. I

strongly

believe that life is for living and you should live life now, not limp

around for 10 years until you are old enough to have a THR. I do

however

have some concerns. (I am sure many or most of you have heard that

before)

My main concern is that we are at risk of making the same mistake that

we

have done before. This operation seems like a brilliant operation and

so

we

rapidly expand the group of patients suitable to have it. We expand the

indications faster than the research is created. This is a mistake that

was

made with unicompartmetal knees in the UK. Before long everybody was

doing

this operation on all different types of patients. Soon the group of

patients that it was not suitable for started to fail. Suddenly the

operation had a bad name and most people stopped doing it. Then they

went

back to the drawing board - identified who it actually was suitable for

and

now it has a good name again. The whole process has taken more than a

decade.

Although this implant is more stable than a THR and although it has no

poly

debri the increased surface contact between the head and cup (As apposed

to

a 22 - 28mm head in a THR) may well bring new problems. We dont know

yet -

I certainly hope not.

The other thing that I havent had an answer to is although we preserve

more

femur and therefor revising the femur is easy, we now take more

acetabulum

because the cup is much bigger than traditional THR acetabulae (Because

the

head is bigger). This may not be an issue because the revision surgeon

can

rebuild bone on the acetabular side easier than on the femoral side, but

what if the femoral component fails, you go to convert to a THR but the

Cup

is well fixed. How easy will it be to remove the large cup witout doing

some major excavatiuon of bone on the acetaular side.

I would recomment that anyone having this operation should continue to

respect that we cannot reproduce anything as resistant or maleable as

bone

or cartialge.

Although it is necessary to stimulate bone to increase it strength, over

stimulating bone can equally cause " resortion " of the bone. The

differences

between bone and metal are so massive that high impact loading could

result

in lysis rather than stimulation of bone. Until we know differently I

would

be wary of carrying out high impact activities.

A million cycles in a pool should theoretically not be a problem. One

of

the theoretical beauties of a metal/metal surface is that it will

" repolish "

itself and any metal debri will not trigger a granuloma formation the

way

polyethylene will.

.

Rememebr If you are having this operation because you have severe pain

on

a

day to day bases but are too young for THR then thank your lucky stars

there

is an operation that can take you pain away. But until we know

diffrently

treat your new hip with respect. If it will allow you to become active

again so that you can keep your bones and the rest of your body healthy

that

is great but remember that you no longer have cartialge lining your

joints.

If you are planning to have this operation because you cant play rugby

or

some other hig himpact sport any more then maybe you should think again.

August 20, 2003

hi david-

the following are but a few links with more info on hip resurfacing,

the guy who puts this group together has loads of good links in the database.

http://www.resurfacingofthehip.com/

http://www.midmedtec.co.uk/hip_resurfacing.htm

http://www.wmt.com/Physicians/Products/Hips/CONSERVETotalHipSystem.asp <<<<<<a

" m-o-m " thr revision system

http://www.grossortho.com/hipre.html <<<<excellent macromedia flash animation

http://www.jri-oh.com/hipsurgery/surface.asp

http://www.minimalinvasivehip.com/hip-surgery-resurfac.html

http://dukehealth.org/ortho/total_joint_hip_resurfacing.asp

http://www.hip-clinic.com/en/html/home_en.html

see ya, jeff

RE: active vs. inactive lifestyle after

resurfacing?

>

August 20, 2003

> Another question that someone may know but that I have not seen a

reference

> too -- is the acetabulae cup (in general) actually larger or does

the thiner

> metal surfaces simply allow a larger head? The Corin resurfacing

cup comes

> in sizes from 46-62 mm. The Stryker cup for 28-36 mm THR alunima

heads range

> from 46-68 mm.

In general the outside diameter of the acetabular componentis NOT

larger than a typical THR. The typical THR has a two piece shell and

liner and the combination takes as much space as the monolithic

actetabular shell for the resurfacing.

Also the point raised by another is true, all the manufacturers (OK,

I don't know for sure about CenterPulse) offer a large diamter metal

THR head that can be matched with the acetabular component in case

the femoral side loosens.

-

August 20, 2003

writes:

" If you are putting an uncemented component into bone then you

rely on bony " intergrowth " to the back surface of your impalnt. If you over

stress that interface with jarring impact you could potentially cause micro

fracture at the interface and interfere with the " bond " between the two

interfaces. This could ultimately give rise to loosening. "

Does anybody know of some papers/studies on how bony ingrowth responds to

different types of stress? Does the bone at the interface respond to stress

like a " bone-bone " break such the things like weight training are actually

helpful or is it more like a metal where fatigue will come in w/ usage?

Also, walking at 1 km/h puts a force of about 2.8*(body weight) on the hip

joint, walking at 5 km/h yeilds 4.8*(body weight) and jogging about

5.5*(body weight). [G Bergmann J. Biomech 26 [1993]]. Walking at a rate of

three miles/hour doesn't seem all that fast -- sort of normal walking, yet

it yelds a force multiplier on the hip of 4.8. If you go to jogging you

move up only a factor of 0.7. I'm not sure how well accepted these numbers

are, but if this is in general true it would seem that the difference

between normal walking and running in terms of forces felt by the hip are

not all that dramatic. The question becomes -- why do we consider walking to

be " low-impact " but running " high impact " ?

August 20, 2003

Hi ,

Thanks for joining in.............. and raising some valid concerns for what

some chose to do with their new prothesis...........

For myself I was just glad that someone had the skill to give me back some

of the opportunities for just normal life movements and I have little chance

of doing any of the heavy duty things due to a spine that didn't like 35

years of a fused hip......... Even exercising in a pool often upsets my

spine without doing a couple of k's of running etc.........smile. So nothing

much that the BHR could dish up, or I could do with it, could rival the

damage having a fused hip was doing to my body..........

Have you ever seen any OS chip apart a fused hip and put a BHR on it? I was

Dr. L Walters 3rd successful one in Australia. I could never get anyone

interested in doing a THR because I had extensive osteomylitis in my teens

with bouts within the hip bone in question.......... I am hoping that this

BHR will see me out as I do appreciate the risks involved playing with my

femur too much.......... without all the dislocation issues.

Edith LBHR Dr. L Walter Sydney Aust 8/02

> Forgive me if I am an interloper into your group. I am an orthopaedic

> surgeon in the UK. I actually specialise in shoulder surgery and I have

at

> present two completely normal hips. I realise the group is for people who

> have or are having surface replacement but came across your group while

> doing research for my 73 year old father in law who just had a surface

> replacement. I am fascinated by the level of research that many of you

have

> done into this subject and have found your information very informative.

>

August 20, 2003

At 06:23 PM 8/19/2003 +0100, you wrote:

>Although this implant is more stable than a THR and although it has no poly

>debri the increased surface contact between the head and cup (As apposed to

>a 22 - 28mm head in a THR) may well bring new problems.

Do you really think there is increased contact? There is definitely

increased surface area, but I would venture to guess the actual stress is

far greater on a regular THR. Picture you at 200 lbs, and your wife at 100

lbs, both standing on your kitchen linoleum. You are getting ready to

go to dinner together, and you are wearing your dress wingtips while your

wife is wearing a pair of spike heels. Which one of you leaves a dent in

the linoleum from the concentrated force on a small surface area? On the

other hand, the large diameter of the resurface bearings enables a layer of

synovial fluid to get between the two bearings which makes for little wear

on the bearing surface.

>The other thing that I havent had an answer to is although we preserve more

>femur and therefor revising the femur is easy, we now take more acetabulum

>because the cup is much bigger than traditional THR acetabulae (Because the

>head is bigger).

Nope, the outside diameter is pretty nearly the same. It is the inside

that is different to accomodate the poly liner on standard issue THR's or

the larger diameter head on resurfacing or large head m/m THR's.

>.

>Rememebr If you are having this operation because you have severe pain on a

>day to day bases but are too young for THR then thank your lucky stars there

>is an operation that can take you pain away. But until we know diffrently

>treat your new hip with respect. If it will allow you to become active

>again so that you can keep your bones and the rest of your body healthy that

>is great but remember that you no longer have cartialge lining your joints.

Amen! But then I haven't had any cartilage lining my hips for several

years. THR was a devil I knew (sadly only too well as a close friend has

had 14 dislocations of her THR's with both open and closed reductions,

revisions, a locking ring on one side, and now waiting for another locking

ring). That is a devil that I wanted NO part of!!! I was happy to jump

into the unknown since it certainly appeared to be better for my situation

(and thus far has proved itself so!)

Thank you for jumping in. I know I appreciate hearing from professionals

in the field.

C+ 5/25/01 and 6/28/01

August 20, 2003

Hi

I have to say I admire and respect you as you seek more information about hip

resurfacing. My opinion of many of the OS's I've contacted had been really

lowered when it was obvious to me that the particular surgeon had not kept up

with the updates of resurfacing. That and the fact the insurance companies

refuse to objectively examine the breakthroughs in technology. With the

exceptions of Dr DeSmet, Dr Gross and the others that deal with the trials here

in

the states, I felt the OS's and the insurance companies are only in it for the

money and screw the best interest of the patient. Coming to this site you

demonstrate to me a genuine concern, interest and objectivity in learning the

facts.

You are a breath of fresh air and renew my faith in mankind. GODSPEED.

Sincerely

Lloyd

Pre-op Dr DeSmet RBHR

August 20, 2003

Dr Walter is a brave man, so are you.

Your surgery sounds awesome in the true sence of the word. Totally

sympathise with your motivation for having the surgery.

Re: active vs. inactive lifestyle after

resurfacing?

Hi ,

Thanks for joining in.............. and raising some valid concerns for

what

some chose to do with their new prothesis...........

For myself I was just glad that someone had the skill to give me back some

of the opportunities for just normal life movements and I have little

chance

of doing any of the heavy duty things due to a spine that didn't like 35

years of a fused hip......... Even exercising in a pool often upsets my

spine without doing a couple of k's of running etc.........smile. So

nothing

much that the BHR could dish up, or I could do with it, could rival the

damage having a fused hip was doing to my body..........

Have you ever seen any OS chip apart a fused hip and put a BHR on it? I

was

Dr. L Walters 3rd successful one in Australia. I could never get anyone

interested in doing a THR because I had extensive osteomylitis in my teens

with bouts within the hip bone in question.......... I am hoping that this

BHR will see me out as I do appreciate the risks involved playing with my

femur too much.......... without all the dislocation issues.

Edith LBHR Dr. L Walter Sydney Aust 8/02

> Forgive me if I am an interloper into your group. I am an orthopaedic

> surgeon in the UK. I actually specialise in shoulder surgery and I have

at

> present two completely normal hips. I realise the group is for people

who

> have or are having surface replacement but came across your group while

> doing research for my 73 year old father in law who just had a surface

> replacement. I am fascinated by the level of research that many of you

have

> done into this subject and have found your information very

informative.

>

August 20, 2003

I think it is not the force put through the joint, but the rate at which the

force is put through the joint that will give rise to the jarring and

possible micro-fracture.

Walking is less jarring which is why I would say that it is safer. In fact

lifting weights should not be risky as I see it. (Other than to your back)

RE: active vs. inactive lifestyle after

resurfacing?

writes:

" If you are putting an uncemented component into bone then you

rely on bony " intergrowth " to the back surface of your impalnt. If you

over

stress that interface with jarring impact you could potentially cause

micro

fracture at the interface and interfere with the " bond " between the two

interfaces. This could ultimately give rise to loosening. "

Does anybody know of some papers/studies on how bony ingrowth responds to

different types of stress? Does the bone at the interface respond to

stress