Re: replacement joints.

January 12, 2006

Hi, does anyone know about replacement joints and if they are possible if you

have p.a. I have severe p.a. in my left ankle, no where else. On maximum dose

of mtx. just had sulfasalazine added. Tried to research on internet whether

replacement ankles joint suitable for me, but cant find anything. my Consultant

says that it is not good that I am on such strong medication for one joint, but

hadnt thought of replacement ankle joint when I spoke to her and she didnt

mention it. She says it is not that common for p.a. to affect only one joint

and no where else. Anyone else out there the same. I would like to hear from

you.

Geraldine Dullaway

Kent, U.K.

January 12, 2006

Hi Geraldine,

Joint replacement technology may not have yet advanced to the point of being

able to produce a successful replacement ankle.

Successful joint replacement started wth hips and shoulders because they are

relatively simple in comparasin to other joints. They are essentially the

intersection of 2 bones, a cup and a ball. The ways in which it is expected to

move are easily identified and recreated.

Knees were a more complex engineering feat because not only does the joint

have to swing back and forth on a plane, it also should have a controlled amount

of give to rotational torque, which has only recently been accomplished.

This torquing of the knee is complicated, too much torsional resistance and you

could rip ligaments loose. Not enough and the knee will be stiff, causing

increased wear rate on ankles and hips.

Unlike natural joints, the syntetic joint is not adaptive, it can't adjust

itself over time to account for changes in how the joint is being stressed. So

getting the tension on the torsion spring of the knee joint just right is

difficult and if successful may not stay that way for long.

Now for your particular concern, the ankle. You would first have to identify

which of the many movable joints that make up the ankle are at fault. I dont

remember the names of all the bones in the foot, trust me I knew at one time,

dont use it you loose it right?

Let's say the one that is messed up has to slide verticly, 1/8 " relative to

the bone to it's immediate right. It has to slide verticly 1/8 and fore/aft

1/8 " relative to the joint on its left, each of the contact surfaces needs to

bend along the horizontal plane etc

Without dreaming outloud any further I think you can see that the problem in

the ankle may not require the replacement of a single joint to correct. 1

bone may be a part of 5 joints.

So the ankle is not as simple as 1ball, 1cup like the hip. It is many bones

and many joints collectively functioning as a unit. Perhaps one day some

bright engineer will come up with a ball type joint with miscelleneous springs

to

replace the entire foot. In the mean time, make sure you dont get arthritis

in your big toe cause you would need it to control the ball/spring foot. Orin

In a message dated 1/13/06 5:15:44 AM Central Standard Time,

geraldinedullaway@... writes:

Tried to research on internet whether replacement ankles joint suitable for

me, but cant find anything

January 14, 2006

I can only suggest that you look up new england baptist hospital in boston

,mass.Theyare rated number 3 in us for joint replacement . They do have a

website . ou could probably get info on joint replacement there

cathy from ma. II had 3 hip replacements there . Right hip twice because of

hip displasia .

cathy from ma.

January 16, 2006

Geraldine,

Total ankle replacement is in its infancy, compared to hip and knee

replacement. It does exist, however, and can provide good relief of pain and

continued motion of the joint. HOWEVER, there are specific indications for its

use. This is because as it is in its early investigations, the lastibility of

this joint is unkown. Also, as it is not worked out fully, there are greater

chances of getting a complication.

To see if an ankle replacement will help you, you will need to get x-rays of

you ankle joint. First of all, it needs to have x-ray changes consistent with

arthritis. If your pain is coming from the inflamed synovium around the joint,

and the joint itself has no irregularities on x-ray, an ankle replacement will

NOT help you. Second important relative factor is age. If you are young and

want to be active, then an ankle replacement would not be suitable for you. You

would not be allowed to run after an ankle replacement. Perhaps an ankle fusion

might be more appropriate in this instance.

For some information that may help, try www.agilityankle.com.

Hope this helps.

Regards,

Todd

geraldine dullaway <geraldinedullaway@...> wrote: