hip replacement by liaoqinmei

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									                     hip replacement




  This information will be useful for those in whom a hip replacement operation is
already planned and for others who have yet to decide. If any of the information is
 not clear then it should be discussed with your General Practitioner or Surgeon.




                              D J Bracey, FRCS
                       Consultant Orthopaedic Surgeon
                                             2

Total hip replacement to replace a damaged joint is an operation that has been in
regular use since the early 1960's. The new ball and socket joint functions extremely
well and this operation has become a very reliable and safe procedure.

There are three types of hip replacement that I use;

          Exeter
          Corail
          Hip resurfacing


           The Exeter hip replacement was originally developed by Professor Ling in
           Exeter about 30 years ago. The replacement has a small femoral head
           that has very low friction within a cup, which is fixed with bone cement.
           The ball is fixed on to a polished, tapered, stainless steel stem, that is also
           fixed with cement. This hip is suitable for all ages and has a long and
           successful track record.



           The Corail hip was developed in France and has been in use for more
           than 25 years. The stem is made of titanium. It has a textured coating of
           hydroxyapatite, that looks like white coral, hence its name (‘corail’ is the
           French word for coral, from which HA can be synthesised). The coating
           enables bone to bond directly to the metal producing a permanent fix,
           without the need for cement. It is used in younger people with strong
           bone.


           Hip resurfacing is a more recent development. This operation is reserved
           for the under 65s, usually men, who wish to continue strenuous activities.
           Both parts are made of stainless steel. Results are good, but the
           operation is more difficult. Long term results are not yet known.


All these different types of hips have different pros and cons, in terms of the ease of
the operation, how much they preserve bone, how long they might last, and ease of
revision. Once implanted however there's not much to choose between them and
all will 'perform' very well. The variety allows a choice of the ideal hip for each
individual.


indications for operation
The operation is done to relieve pain. People vary greatly in their response to pain
but will usually be bad enough to limit walking, and to cause pain at rest. Pain killers
and anti-inflammatory tablets are often ineffective. Sleep is disturbed. By the time
the hip becomes this painful there is often stiffness as well as shortening of the leg
itself. Some people have such pain that an operation is required before their
disability is this bad, yet some seem to be able struggle on for a long time.

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In the early phase as the hip first starts to get painful, there may not be much
restriction of activities. As things progress there will be times when the hip becomes
extremely painful. This may make the person feel that they will have to have
something done because they will often say 'if it's like this now, what's it going to be
like when it's really badly worn?' The answer is that the peaks and troughs of pain
often smooth out, such that in the established phase, the pain, though more
continuous, does not reach such a severe level. It is better therefore to leave the
decision for an operation as long as possible. This allows a more accurate
assessment of the overall level of pain, rather than responding to the early severe
pain that might settle.

preparation for operation
Your General Practitioner will advise of any medical problems that might interfere
with surgery. Anyone who is overweight should lose weight due to the increased
risk at the time of the operation, and the risk of breaking the hip prosthesis in the
long term.

Smokers should stop several weeks before surgery to avoid an increased risk of
chest complications and interference with bone healing. You should get an up to
date list of tablets from your doctor and discuss any changes for the operation (eg
stopping aspirin)

In men over the age of 65 enlargement of the prostate will sometimes cause a
slowing of the stream. If this has been a particular problem you should discuss it
with your doctor as it can cause post-operative problems.

Before the operation try to keep your hip joint flexible. Any problems ulcers around
the foot or ankle, or trouble with the toes, must be dealt with well in advance, to
minimise the risks of infection that could spread to the new hip.

Prior to the operation a full examination, blood tests, ECG, x-rays, etc are done at
the 'Pre-Assessment' clinic. You will need to bring a full list of your medications and
your fitness for operation will be carefully assessed.

Before coming into hospital make sure you have a bath or shower, preferably using
a medicated soap such as Hibiscrub (Chlorhexidine 4%) which you can get from
chemists. Be particularly careful to clean your feet and trim toenails. Most wound
infections are due to your own skin organisms so the cleaner the better!


will the operation be straightforward?
Some operations are easier than others and specific potential difficulties will be
explained. The operation will be easier if your hip is flexible and if you are slim. It
will obviously make your recovery easier if you have no other bad joints.




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If the hip has been giving trouble the leg is normally short and you may have already
been given a shoe-raise. After the operation, if the leg length is back to normal, the
shoe-raise will be removed. It is difficult to get the length of the leg exactly right,
though fortunately differences of less than 1/2" are not usually noticeable.
Sometimes it is necessary to put in a slightly bigger hip prosthesis to get the stability
right and this will slightly overlengthen the leg. If both hips are affected then with the
first replacement that leg will be lengthened. Sometimes a temporary shoe-raise is
required on the unoperated leg until such time as the second operation makes both
legs the same length again.

If you are unlucky enough to have bad knees as well, it is best to get the hip joints
sorted out first. Some knee pain may be ‘referred pain’ from the hip.

hospital procedure
Admission is often on the morning of the operation having had nothing to eat or
drink from midnight. The hip will be marked with an indelible arrow. Sometimes, in
men, the outer part of the thigh is shaved. The skin all around the hip is cleaned with
antiseptic and wrapped in clean towels. You will be given elasticated stockings to
wear to keep the circulation in the veins of the leg brisk. This helps avoid
thrombosis.

The operation is usually done using an epidural or spinal block with sedation or a
light general anaesthetic

After the operation you will be sedated and comfortable. You will have an
intravenous infusion (drip) in your arm. You may receive a transfusion of your own
recycled blood ('Orthopat'). The drip stays in for a day or so. Usually a small tube
(catheter) will be put in the waterworks whilst you are in the operating theatre. This
is left in for a few days to prevent the bladder getting too full and saves having to
use a bedpan. There will be some dressings over the outer side of the thigh,
sometimes with a series of white sponges that help compress the wound to stop
bleeding. There will be a few small drainage tubes leading away from the area.

post-operative routine
You will be encouraged to keep your lungs clear by regular deep breathing and
coughing. The circulation in your legs is helped by moving the feet up and down at
the ankle to encourage contraction of the calf muscles. This increases the
circulation in the leg veins and helps prevent thrombosis (a blood clot). The
operated leg can be moved up and down right from the start and this is a good thing
to do. You can move the hip and knee so that the knee comes about 6"off the bed.
Above your head, fixed onto the bed, is what we call a "monkey pole" that you can
use to pull on to help change your position.

The first day will be spent in bed sitting up. Your appetite may be poor for the first
few days but you will be allowed to eat or drink if you feel like it. After the first
24hours the various tubes (drip, drains and catheter) will be out and if you feel all
right you will be got out of bed to stand and take a few steps. Over the next few


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days you will gradually get more mobile, walking at first with a frame and then elbow
crutches or sticks. A small daily dose of heparin ('Fragmin') helps to prevent
thrombosis. Unfortunately, the blood thinning does make for more bruising and
some oozing from the wound and drain sites. The hip will be x-rayed.

You would usually be ready for home about 5-6 days after the operation. The
wound by then will be healing well (if you have had a 'subcuticular' stitch it will be
under the surface and will dissolve with no further attention - if clips have been
used, they are removed at 10 days, usually in your GP’s surgery). Dressings on the
wound can be taken off on the 14th day after the operation. By then the scar can be
considered waterproof.

You may be given soluble aspirin to take home, for its blood thinning effect. If so,
you will be given another information sheet about this whilst in hospital. If you are
already taking aspirin for some other reason before your operation, ask your doctor
if you can stop it 2 weeks before admission, as it may otherwise increase bleeding.

convalescence
Most people can leave hospital in a car as long as there is plenty of leg room. The
front seat should be moved back, with the seat slightly reclined.

It is not a good idea to go back to an empty house. It is best if at all possible to have
a helping hand for the first week or so. For those who normally live alone, it may be
worth enquiring about some additional convalescence for a further week in a nursing
home. It's best to try to get this arranged in advance of your operation. Your GP
surgery should have details of suitable places.

The first three months of convalescence should be considered a time of rest and
care for the hip. In particular, the movement of the joint should be restricted so as
to avoid excessive flexion to avoid the risk of the hip dislocating (coming out of joint).
You should avoid sitting in low chairs and beware of trying to reach your foot to put
on shoes or socks. The Physiotherapist will give you advice on what not to do.

After an operation using an uncemented stem it will be necessary to keep some
weight off the hip using crutches, to allow undisturbed bone healing, for the first 6
weeks. Following an Exeter hip or a resurfacing, full weight bearing is allowed from
the start.

You will need to continue to sleep on your back for the first six weeks, as you did in
hospital. The hip may still be more comfortable with the legs slightly separated. It is
possible to turn slightly from side to side but the hip will feel too tight to turn
completely on one side. this should only be done with some pillows between the
legs to keep them apart.

For the first six weeks you should be very careful to avoid flexing up the hip too
much. It can make it impossible for you to actually touch your toes and so it will still
be difficult to put on shoes and do up laces. You may find it necessary to reach
behind you and flex up the knee to get to your foot. There may still be long-term
problems with trying to cut your toe-nails. The new hip will not always flex up past a

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right angle and should not be pushed further. It may still mean then that certain aids
will be required in the long-term, such as long-handled shoe horns, etc. For those of
you who may be thinking about having a hip operation but can still easily reach your
foot, you should bear in mind that even after a successful hip operation that such
movement may not be possible to do safely. This is one of several reasons why we
do not usually advise hip replacement too early.

By the time you get home the wound should have healed sufficiently for you to have
a bath. Some people prefer to start with a small seat in a shower. If your toilet seat
is low, a raised seat can be organised if you ask the therapist.

You can drive your car to your first post-operative visit at six weeks, so long as you
have sufficient leg room. At first it may be sensible to move the seat back and
incline it backwards so as not to flex up the hip too much.

At this stage you can stop wearing the elastic support stockings which you will have
been given in the hospital.

Your first outpatient visit will be to the Physiotherapist’s clinic. Your progress will be
documented and the x-rays passed on for review. At this stage the scar will still be
healing. The stitch running under the skin will be dissolving leaving a slightly red
zigzag line. Once it has completely dissolved (2-3 months), the scar will stop itching
and gradually fade. When you look down over the hip, you may notice that the back
part of the scar looks as if it is bulging slightly. This is quite normal and will
eventually flatten out. It occurs because at the start of the operation you are
positioned with the legs slightly crossed, but at the end of the procedure the leg is
put out to the side to relax the muscles for closure. It leaves the muscles rather
more prominent for the first few months.

Once you have been seen for your first post-operative visit (usually six weeks after
the operation) you should be ready to try some more normal activities, but you
should restrict what you do for the first six months as the hip will still be healing.
The hip is vulnerable for the first few months, as the bone around the hip has to
heal, and this is a very slow process.

Once the hip is fully healed (six months), it is very robust and most normal activities
can be attempted. In the long-term it is nevertheless best to avoid any sudden
strains or jarring of the joint and to avoid excessive movement.

risks of operation
A hip operation is now routine but it is a major procedure and there are bound to be
risks. A comprehensive list of all potential problems would be too alarming so only
the most common problems will be mentioned. Most things that can go wrong will
have done so in the first few weeks. So, if all is going well at the time of the first
follow up, you can expect a good long term result.

As with any major operation, heart and lung problems can occur. If there is any
concern as to your medical condition then an assessment would be organised pre-
operatively. We would be particularly concerned with any previous history of heart

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attack or stroke.The most important complications of hip replacement to consider
are as follows:

   Thrombosis
   Dislocation
   Infection
   limp

Thrombosis means a blood-clot has formed, usually in the calf of the operated leg,
which can cause leg swelling. More seriously, if the clot moves into the circulation it
can cause an obstruction in the heart and lungs. It is more frequent in those who
are overweight or who have had a difficult operation. Most people will be put on a
small daily dose of Heparin to thin the blood and help prevent this complication.
Aspirin may also be advised to take once you have gone home for the same reason.

After a hip operation the thigh itself is always swollen and sometimes there is some
fluid in the knee. We are only concerned when there is significant swelling over the
shin and ankle. If a thrombosis is detected it is treated by anticoagulants. If the clot
moves out of the leg into the lung (pulmonary embolism) then this is more serious,
though fortunately rare.

Dislocation - In the first few weeks there is a possibility that any abnormal
movement of the leg could cause the new joint to dislocate though fortunately this is
rare (less than 1:100). This can happen if one leg is crossed over the other or if the
operated leg is flexed up too much. As the weeks go by, the hip gets more stable. It
is rare for the hip to dislocate after six months convalescence. If you are
unfortunate enough to fall and dislocate the hip then it will need to be put back
under a general anaesthetic. Fortunately it does not damage the joint prosthesis
itself and the hip can still be perfect afterwards.

Infection - Post-operative infection can cause a complete failure of the operation
with subsequent rejection of the implant, necessitating a further operation. Such a
complication is extremely rare (less than one in two hundred operations). You will
be given antibiotics during the operation. The bone-cement itself also contains
antibiotic. Antiseptics solutions are used to wash the wound throughout the
operation. The operating theatres use 'laminar flow' with bacteriologically filtered air.
Special ‘space-suit’ operating gowns are used by the surgeon. In the very rare event
of an infection occurring it is extremely difficult to eradicate and usually means an
operation to remove the joint prosthesis leaving a false joint. This would leave a hip
that is weak and makes it difficult to walk. This disastrous complication is very rare.

Limp - Though this does not rate as a serious risk, it can be disappointing to find
that even after a successful operation that you may still walk with a limp. This
happens in 5-10% of cases. For the first few months everyone has a limp and
walking aids are essential. As the muscles heal, walking gets better. Careful
measurements show that even in people who think their hip has returned to normal,
have at least a 10% permanent muscle weakness due to scarring in the hip muscles
from the operation. If there is still an obvious limp at 6 months it may mean that
there is a significant weakness and this may be permanent. This will mean that
even though the hip may now be pain free, the person walks with a 'swaying' gait

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('Trendelenberg gait') and the hip may feel 'tired' after prolonged activity. The hip
replacement will still feel much better than the painful limp from the arthritis present
before the operation. It may take longer for the limp to disappear after resurfacing
as there is a lot more bone healing required before you see the final result. A
persistently bad limp may mean that some of the muscle repair has failed and
sometimes another operation will be advised. Some people find that their foot turns
out after hip replacement. This again may be due to temporary muscle weakness.

People often ask how long a hip will last. This is as difficult as asking how long a
new car will last! It depends how much work it has to do and whether there have
been any technical problems. For lightweight individuals who do not do very much
in the way of physical activity it can last twenty to thirty years.

Heavyweights who abuse their hip and continue with heavy work can loosen or wear
out the hip within ten years. This is why hip resurfacing is sometimes considered as
an alternative to conventional replacement in heavyweight men as the bearing is
stronger (though this has yet to be proved by long term studies - resurfacing has
only been done since the early 90's) The lighter the person the longer the joint will
last. In those accepting a sensible lifestyle and who continue to take care of the
joint, it should last a lifetime.

If, in the long-term, loosening or breakage of the replacement occurs, a further
operation may be necessary. The replacement is removed and a new one
reinserted. These so-called "revision" operations are more difficult with a higher rate
of complications. Nevertheless the joint can be made good again, so long as the
bones have remained in good condition and no infection is present. If it is not
possible to reinsert a new prosthesis then it occasionally has to be left as a false
joint (pseudarthrosis) leaving the leg very weak and uncomfortable.

special long-term precautions after hip replacement
Any simple infection should be treated promptly to avoid any spread through the
bloodstream to your new hip. In particular, a tooth abscess should be treated
quickly with antibiotics.

Routine dental treatment does not have to be covered by antibiotics. You should
make sure your dentist knows you have a joint replacement but it is unlikely that he
will have to give you any antibiotics.

There are occasionally problems at airports with metal detection equipment that can
give a positive reading with a joint replacement. This is more likely if you have had
both hips replaced, or if the airport is in a high security area where the machines are
set at a higher sensitivity.

Whilst the idea is to return to as near as possible a normal lifestyle, activities such
as running or jumping which might jar the hip should be avoided. Walking long
distances is quite satisfactory and one could anticipate a return to moderate
activities such as golf. People can get back to very vigorous activities such as
mountaineering or horse riding, but whilst these may be possible it is probably not
in the best interests of the hip in the long term.

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long term follow-up
The first follow-up at six weeks after the operation is to make sure nothing has gone
wrong. Most of the serious problems will have shown themselves by this time, so if
all is well, the rest of the convalescence should be straightforward and there is not
much that needs to be checked. You may find then that you will be discharged from
follow-up at this stage. This does not mean that you are fully recovered. It will take
the full six months to really feel that you have got over this operation.

After discharge from the clinic your family doctor will see you if there are any
problems. There is no need to go in for regular check-ups. Hip resurfacing patients
are followed up in the long term to learn more about how well the joints last as the
long term results are not known.

There may be the odd day, or even a week or two, when a hip replacement might
ache, but this is nothing to worry about. If however there is more persistent pain
then you should see your doctor and if there is any concern you would be sent for
an x-ray.




D J Bracey                         11/29/2011c:\docstoc\working\pdf\d5430033-a12e-4022-bfd9-
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