Leeds scientists at the cutting edge in the search for new and better hip replacements
DOCTORS and scientists at the University of Leeds are helping to transform the lives of 50,000 people in the UK who have hip replacement surgery every year, through their cutting edge research work into new and better designs of hip.
The work carried out by a research group at the university - one of the world's leading centres in the testing of hip replacements - has led to major improvements in the manufacture and production of artificial hip joints.
Now the group's important research was highlighted by leading medical research charity the Arthritis Research Campaign - which is providing almost £132,000 to fund the work - during its Research Week (June 7-13).
The awareness week focused on the enormous success of joint replacement surgery over the past few years, the charity's role in developing ever-better surgical techniques, and the resulting benefits for thousands of arthritis sufferers. It also aimed to restore public confidence in joint replacement, following public concern earlier this year over the failure of one type of hip replacement.
"More than one per cent of the population benefit from artificial hip joints, as a surgical treatment for arthritic hips," explained Professor John Fisher, of the Department of Mechanical Engineering.
"This has proved an extremely successful operation, with up to 75% of the hip joints functioning well after 15 years. However, as the general age of the population gets older, and their activity levels and expectations for quality of life improve, there are demands for prostheses that will last well beyond 15 years, and into the third decade."
Around 5,000 people have hip revision surgery every year - that is, a second hip replacement to replace the joint which has failed. The challenge facing orthopaedic researchers is to find ways of prolonging the life of primary hip replacements, to prevent the need for revision.
The main reasons why hip replacements fail is because the joint becomes loose. This is due to the production of microscopically sized particles of the plastic part of the hip joint, which are produced from the rubbing of the hard metal against the socket during movement, and stimulating inflammation, which in turn leads to bone loss, or osteolysis.
"The aim of our research is to determine the mechanical and material conditions which can be used in the design of hip replacements that will produce the least volume of inflammatory particles," added Dr Eileen Ingham, of the Department of Microbiology.
Using an ARC equipment grant, the Leeds team built a "six station hip joint simulator" in their laboratory, which is being used in three studies of wear and tear particles in artificial hip joints, and has already led to the development of a new type of polyethylene (plastic).
The team's work has already led to changes in the manufacture of artificial hip joints in the UK - methods of sterilisation have been improved - which should increase the lifespan of artificial joints.
They have also recommended that ceramic should be used rather than metal femoral heads, which they also expect to be acted upon.
- The ARC, which is the fifth biggest medical research charity in the UK, is the only charity dedicated solely to finding the cause of and cure for arthritis and other forms of rheumatic disease.
