SCIENTISTS at the University of Connecticut in the United States have developed a patch that generates tiny amounts of electricity to trigger the growth of cartilage, the tissue that acts as a cushion to stop bones from rubbing against each other and causing pain.
These tiny electrical pulses, released by the implant when the knee joint moves, stimulate nearby cartilage cells to start growing until they form a 'patch' of new cushion.
Around 8.5?million people in the UK have painful joints due to osteoarthritis, or 'wear-and-tear' arthritis - and osteoarthritis of the knee, the strongest joint in the body, is estimated to affect one in five adults aged over 45.
Articular cartilage, a smooth, slippery substance, coats the ends of the bones where they meet in the joint and acts as a cushion. But it becomes frayed over time, resulting in bone rubbing on bone, pain and loss of movement.
Treatment ranges from painkillers to ease the discomfort, to physiotherapy and knee braces that support and strengthen the muscles around the joint.
An estimated 60,000 people undergo a knee replacement in the UK every year because, unlike other tissues in the body, articular cartilage cannot regrow or heal because it lacks the necessary blood vessels.
Now researchers at the University of Connecticut have found that low levels of electricity can help trigger the growth of new cartilage cells.
They have developed a small scaffold which looks like a patch and can be matched to the size of the defect and surgically implanted.
It is made from a biodegradable material, Poly-L-Lactic acid (or PLLA), a type of plastic.
This has a property, called piezoelectricity, which means it produces a tiny burst of electricity when squeezed - the movement of a joint, such as walking, causes the PLLA scaffold to generate a weak but steady electrical field.
This encourages cells to colonise it and grow into cartilage. The implant itself then eventually biodegrades.
Animal studies by the researchers showed that after one to two months, robust cartilage grew back inside the joints. By contrast, there was little or no healing of the damaged cartilage in a control group that received a standard tissue scaffold, reports the journal Science Translational Medicine. Clinical trials in humans are planned soon.
Mike McNicholas, a consultant orthopaedic surgeon at Liverpool University Hospitals, said: "Piezoelectricity has been found to be incredibly widespread in body tissues, and is present in some of the body's building block molecules, such as collagen.
"Electrical stimulation is recognised as a way of helping broken bones heal quicker and has been in clinical use for decades.
"This study's results are very impressive. It will be interesting to see if they are reproducible in man.
"The development of this novel therapeutic implant to restore cartilage volume and fill in defects could be a game-changer in the battle against arthritis."
© Daily Mail
