Hip Replacement:
The Facts History
Hip
replacements were first attempted towards the end of 1800’s with
gold and ivory being used to replace the femoral head. In the
1930’s Mr Philip Wiles tried to make a hip replacement out of metal
at the Middlesex Hospital in London but it was not until after the
Second World War that hip replacement surgery really took off.

Image of Sir John Charnley "pioneer of total hip replacement in the
U.K."
In Paris
Professor Robert Judet and his brother designed a partial hip
replacement to treat hip fractures whilst in Norwich Mr McKee and Mr
Watson-Farrer and in Manchester Professor John Charnley also devised
their own hip replacements. Their results, although not perfect, in
reality became the first generation of modern hip replacements with
further advances in time being made by Professor Muller from
Switzerland and Professor Ling in Exeter.
In the United
Kingdom over 40,000 primary (first time) hip replacements are now
performed every year. The overall success of this major operation
is about 95 - 96%.
Indications
The
main reasons for having a hip replacement are osteoarthritis,
(wear and tear), of the hip joint limiting the patients’ quality of
life due to pain and loss of independence and mobility. Sometimes
‘hip replacements’ are also performed for inflammatory arthritis,
(such as rheumatoid arthritis) and for fractures and less commonly
for cancer. The operation normally takes 1 - 2 hours with most
patients being in hospital for 5 – 7 days.

Please click the illustrations above to enlarge
them.

An Arthritic Hip and a Normal Hip
X-ray.

A Modern
Cementless Total Hip Replacement Post-Operative X-Ray.
Implant Design
Mr
Charnley uses both cemented fixation and cementless fixation. In
both of these cases the upper thigh bone (femur) is replaced by a
metal ball on a metal stem inserted into the marrow cavity of the
bone. If the bone is strong, then a “press fit” can be achieved
with a biological calcium crystal based coating. Where the marrow
is poor then antibiotic loaded cement is used as a grout.
The hip socket (acetabulum) may also be cemented or
cementless and the ball articulates usually with a plastic like
material – a high density polyethylene.

Artists Impression Of A
Cemented Hip Replacement, The Green Ink Representing The Cement.
Please click here to enlarge
the image.
In younger and very active patients ceramic heads or
metal on metal articulations may be used.
The cementless system Mr Charnley uses is the Corail
design that has been in clinical use for twenty years with excellent
results from the United Kingdom, Scandinavia and France where it was
originally designed. A Trilogy acetabular shell is his preferred
metal acetabular liner.

Hip socket component for
insertion without cement, the magnified image, showing bone cells
growing onto the roughened surface for secondary anchorage.

A
cementless femoral component with bio-active surface (Hydroxyapetite)
and a ceramic modular head.
When Mr
Charnley uses a cemented hip it is a standard hip replacement called
the CPT (Collarless Polished Tapered) which was designed by
Professor Ling and has been available for over a decade.

Collarless Polished Tapered Hip Replacement.
The results of
this hip replacement are equal to, if not perhaps slightly better,
than many other standard designs. Research at the Avon Orthopaedic
Centre in Bristol, by Mr Gordon Bannister, Secretary of the European
Hip Society, has revealed very good results with this hip prosthesis
and excellent results are also reported in the Danish Hip Registry.
The
performance of the hip replacement is also being studied closely by
several centres in the United Kingdom with an independent assessment
being performed by the Professorial Orthopaedic Surgery Department
of the University of Dundee.
Mr Charnley
likes to follow up the joint replacements performed by himself and
his team on a regular basis.

ZCA Cup Replacement used in Cemented Hip Replacement Surgery.
Benefits
The
main reason for any patient having a hip replacement performed is to
rid them of their arthritic pain. In doing so unless multiple
joints are affected by arthritis, this should lead to an improvement
in an individual’s mobility and quality of life. Indeed patients
having had a satisfactory hip replacement believe their quality of
life is improved as much as a patient having coronary artery by-pass
for heart attacks or a renal transplant for kidney disease!
Complications
The average life span of all hip
designs is about a decade.
As with any
operation there are acknowledged risks. Most patients are
worried about their anaesthetic but modern day anaesthesia is
extremely successful with rarely patients not waking up after
their anaesthetic, (perhaps a 1 in a million risk). Patients in
their 8th decade do have more pre-existing medical problems than
younger patients and have thus a raised risk of non orthopaedic post
operative medical problems and need to be in good health to consider
hip replacement.
Other risks
associated with the surgery itself are infection from bacterial
organisms and to reduce this Mr Charnley uses antibiotics around the
time of surgery as well as using bone cement with antibiotics in
it. There is still a chance of one or two patients in every
hundred having this complication.
Dislocation,
(the ball coming out of the socket), does occur with hip surgery
with a reported frequency of 1 - 9%. Mr Charnley uses an incision
which has the lowest reported rate of dislocation to try and
minimise this problem.
Blood clots in
the legs and on the lungs (thrombo-embolism) is also reported in
particular in those patients who smoke. It is advisable to give up
for at least 6 weeks before the operation, if not for ever, before a
hip replacement procedure.
There is a
remote chance of damage to the nerves and arteries around the hip
(less than 1 in 100), more so with those hips that have had previous
surgery or are of a rather abnormal shape.
Fractures around the time of implant insertion, (peri prosthetic
fractures) may occur with a frequency of 1%.
Finally
following a hip replacement the surgeons performing the operation
try and balance the leg lengths of the affected and unaffected sides
but this is limited by the more important goals of a stable joint
replacement and leg length discrepancies can be satisfactorily
treated with orthotic aids.
The Post-Operative
Period
Your hip surgery will be performed by an experienced team of
surgeons, nurses, physiotherapists and occupational therapists.
The whole team will try and help you get over the post-operative
period with advice about dos and don’ts (see additional
information).
You will
normally be sent home on a pair of crutches once you are safe and
not before. The team are happy to give additional information
regarding return to work, driving and sexual intercourse.
Self-Help
Patients can help themselves by preparing for surgery. A visit to a
physiotherapist or osteopath may enable patients to learn muscle
strengthening exercises, which will speed up there rehabilitation.
In addition, stopping smoking will reduce the risk of thrombosis and
a healthy diet with vitamins and zinc may also help wound healing.
Training,
Education and Research
Mr Charnley and his surgical team perform
over 200 hip replacements and partial hip replacements, (hemi-arthroplasties), per year.
These are both for various types of arthritis and for fractures around the hip.
The majority of the surgery is performed by
Mr Charnley himself, but also by experienced staff grade surgeons plus higher surgical
trainees. These latter surgeons will have all been personally trained and supervised by Mr
Charnley and by other hip surgeons on their training schemes.
All illustrations on this page
are acknowledged and are supplied for patient information by Schering-Plough/Doctor Direct
Ltd. |