Can measuring“noisy” knees improve arthritis treatment? ask Lancashire scientists.
Scientists at the University of Central Lancashire in Preston are aiming to devise a handy new device for GPs to enable them to monitor the progression of osteoarthritis - by listening to the noises emitted by a patient’s knees.
A collaborative team - led by Professor John Goodacre in the Lancashire School of Health and Postgraduate Medicine and Professor Lik-Kwan Shark in the Department of Technology - is aiming to harness a technique called acoustic emission – which has been used extensively in the engineering industry to detect unsafe buildings and bridges – to test creaky knees for signs of improvement or further deterioration.
During movement, patients’ knees emit sound at frequencies which are too high to be detected by the human ear. Based on their work to date, the team believes that an arthritic knee will emit high-frequency wave patterns which differ from those generated by a healthy knee, and this difference can be picked up by acoustic emission – enabling doctors to keep an “ear” on the progression of arthritis.
The unusual research project is the result of a collaboration involving researchers from several different departments and scientific backgrounds at the university and the nearby Blackpool, Fylde and Wyre NHS Trust, in conjunction with the aerospace industry.
he study, which is being funded by a two-year grant of almost £124,000 from the Arthritis Research Campaign (arc) will involve arthritis patients at South Shore Hospital in Blackpool.
Knees are frequently affected by osteoarthritis, rheumatoid arthritis and other types of chronic arthritis, and it is increasingly important that clinicians have access to safe convenient and reliable tools for measuring accurately if a patient’s arthritis is deteriorating or improving, and whether or not treatments are working,” explained Professor Goodacre.
Ultrasound and MRI are both increasingly used but are expensive and not easily accessible to most GPs or satisfactory for routine, widespread use in clinical practice.
We hope to produce a convenient, non-invasive portable tool for use by doctors and other health professionals in primary care and in hospital to objectively monitor arthritis and responses to treatment.”
It is well-recognised that joints produce sound during normal movement. If two surfaces are smooth and well-lubricated they slide smoothly and quietly against each other, whereas if surfaces are rough and poorly lubricated (for example in an arthritic knee) they will move unevenly against each other, producing a high frequency scratching sound.
The team hope to analyse the high frequency sound from joints by using wide-band acoustic sensors attached to a microphone on a patient’s knee. As the patient flexes and extends their knee the sensors measure the sound frequency emitted by the knee.
The team will try to identify if the sounds made by the knees correlates with cartilage loss demonstrated by MRI. “The equipment we are using at the moment is not purpose-built but if we can prove it works we would go on to design a portable box, a bit like an ECG machine for monitoring the heart, for routine use in a clinical setting,” added Professor Goodacre.
“We’ve already obtained some very encouraging early results, and we believe that this work could revolutionise current practice in the way arthritis is measured and monitored.”
