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What do you need to know about Total Hip Replacement? (THR). Like anything else in life, look at history, because it tends to repeat itself and you may avoid making the same mistakes as others.
Early pioneers devised Hip Replacements made of various materials including acrylic cement, ceramics, metal and polyethylene. The first repeatably reliable & successful THR was devised and promoted by Sir John Charnley around 1960. This was a cemented device using a metal stem and head with a polyethylene socket (acetabular component). The Charnley Hip and similar devices dominated the field of THR from 1960’s and different concepts were gradually abandoned. Unfortunately these early THR’s all suffered from one common flaw that was impossible to get around: after being in place for several years, the plastic would wear and tiny particles would attack the interface between the cement and the bone. This would cause bone to resorb and a new disease was born:aseptic loosening.
To learn more about aseptic loosening, click here.
http://www.thehipclinic.co.uk/AsepticLoosening.aspx
Aseptic loosening was poorly
understood at first. Some labelled it ‘cement disease’ and blamed acrylic bone
cement for what was being seen on patients X-rays. This led to the development
of cementless THR especially in North America. When even these devices suffered
from a similar problem it was labelled ‘osteolysis’ . This is the same process
of bone being eaten away but the pattern is slightly different. It took a long
time for scientists to understand what was happening and why. We still do not
know everything about this mysterious process! Further attempts to avoid
aseptic loosening and osteolysis have led Orthopaedic surgeons to use materials
such as titanium, hydroxyapatite, and oxinium. Ceramics have had a resurgence
of interest after golfer Jack Nicklaus received such a device and his
experience was used in a high profile media campaign in the USA. The field
however remains in turmoil! Be very careful about what you read and believe,
especially if it comes from a commercial source.
So what does the layman do to decide?
First read the link on
Myths, Facts and Fictions.
If you are over 75 yrs of age, it probably
does not matter which hip you get. A cemented hip is reliable and generally
much cheaper if this is an issue. Choose your surgeon by experience and
reputation. Ask about minimal incision hip surgery but do not insisit on this.
Allow your surgeon to make a bigger hole if he/she has to! If you are between
65 and 75 years of age, you must ask what hip you will be getting and why.
Cemented THR of the Exeter, Charnley, Lubinus, Stanmore or Muller type remain
the ‘Gold Standard’ and have improved enormously since the 1960’s There are
good uncemented devices but there are also some that gave spectacularly bad
results. Ask about metal-on-metal or ceramic-on-ceramic. The size of your hip
scar is not the most important issue! If you are under 65 yrs do not rest until
you find an experienced Hip Resurfacing surgeon. See section on Hip Resurfacing
http://www.thehipclinic.co.uk/resurfacing.aspx
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