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Last Updated: Friday, 17 September, 2004, 23:03 GMT 00:03 UK
Tough bone repair cement created
Cement
Tough enough to support 70 stone of researcher
Scientists have developed a strengthened cement to be used in reconstructive surgery.

A University of Birmingham team found standard calcium phosphate cement could be made more than three times stronger by adding sodium citrate.

This means it can be used to repair load-bearing bones such as the long bones of the legs, and the jaw.

The cement is injectable through small needles so it can be easily used even in areas tough to access.

Calcium phosphate cement has been used since the late 1980s years by surgeons as it sets rapidly and has a neutral pH at body temperature.

It can also be impregnated with drugs and proteins to aid the healing process.

However, once set it is brittle, and relatively weak, having only half the strength of most human bones. This is because during the setting process tiny holes, or pores, form in the cement.

This strong cement may replace bone in critical, load-bearing sites and improve the patient's recovery and quality of life.
Dr Jake Barralet
Adding sodium citrate increases its strength by making it less porous. In fact, it becomes so tough that it can be drilled through, and metal screws can be inserted.

Researcher Dr Jake Barralet said: "Concrete is commonly used to patch holes in bones caused by trauma or disease.

"Unfortunately the strength of concrete is generally much lower than that of surrounding bone, making bone grafts difficult.

"Adding a small amount of sodium citrate makes the cement particles pack together better, which combined with pressure to help compaction makes a denser cement with fewer pores.

"This strong cement may replace bone in critical, load-bearing sites and improve the patient's recovery and quality of life."

The researchers hope their cement will be particularly useful as a way to strengthen broken spinal bones, weakened by osteoporosis or, less commonly, cancer.

It may also be useful in the treatment of obstructive sleep apnoea by repositioning the jaw bones.

Assessing the breakthrough in the journal Nature Materials, Tom Troczynski, an expert in materials engineering at the University of British Colombia, called the idea "simple and brilliant".

He said: "The surgeon may soon have access to a much more reliable cement biomaterial to fill bone defects."




SEE ALSO:
'Goo measure' could help hip ops
22 Oct 03  |  Health
Leg bone used to fix spine
17 Jul 03  |  Bristol/Somerset


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