Around 50,000 British people undergo hip replacement surgery to ease mobility and reduce pain each year, but occasionally they become loose and the patient may need further surgery.
Engineers at the University of Bath have now developed a new diagnostic test which will help doctors to determine whether patients who are in pain are suffering from an infection and can be treated with antibiotics, or whether the joint has become loose and surgery is required.
Creator Dr James Cunningham, of the University of Bath's department of mechanical engineering, explained: "This finding is important because surgeons need to know if the pain the patient is feeling comes from a loose joint needing surgery, or from another cause."
The new method measures the frequency of sound produced when the leg's femur (thigh) bone is vibrated.
Doctors can place a piece of vibrating equipment onto the patient's knee and then detect sound vibrations from the joint using an ultrasound device.
If the sound waves are irregular, the doctor will know that the joint has become loose and surgery is needed.
Dr Cunningham added: "The ultrasound method is better than any other method available now, including the traditional x-ray procedure, which can only pick up a large amount of loosening."
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