Could a fat jab ease chronic knee pain?

By PAT HAGAN

Tiny globules of fat that are injected into painful joints could be a radical new treatment for osteoarthritis.
Thousands of the fat particles - each one no bigger than a speck of dust - are injected to protect the cartilage inside the joint from further damage.

Cartilage is the spongy material in the hips, knees, spine, wrists and shoulders that acts as the body's shock absorber, stopping the bones rubbing together.

'Holy grail': Chronic knee pain could be eased by injecting tiny globules of fat into the joint
But injury, illness or wear and tear can cause the cartilage to start breaking down. As bones come into contact, the friction makes the joints swollen and painful.

Around eight million Britons suffer from osteoarthritis. Many rely on anti-inflammatory painkillers though these carry the risk of damage to the stomach if used long term.
Every year, thousands of patients end up having joint replacement surgery.
The scientists who have developed the fat jab hope it will prevent the need for this surgery, or at least postpone it for several years.

The fat molecules, which are manufactured in a laboratory, are soft enough to help cushion the impact from everyday activities, but strong enough not to be destroyed under the strain of a working joint.
The treatment was developed in Israel by scientists at the Hebrew University of Jerusalem and the Technion Institute of Technology.

In tests, the scientists injected the fat particles into hip joints.
The results, published in the arthritis journal Wear, showed the fat jabs reduced the rate of cartilage destruction by 40 per cent compared with 10 per cent with an existing therapy, hyaluronic acid.
(Hyaluronic acid is sometimes injected into damaged joints to help keep cartilage lubricated and spongy.)

The fat jabs are a form of nanotechnology - a technique using moleculesso small they can't be seen with the naked eye, yet which are capable of delivering powerful medicines or treatments deep inside the body. This stops healthy tissue being exposed to the potential side-effects.

The size of the molecules also means they can't be detected by the body's defence systems so they won't be cleared away.
The molecules developed for the new arthritis treatment are no more than one millionth of a millimetre in diameter and are engineered to pass into the cells within the joint, something previously not possible.

Professor Philip Conaghan, from the Arthritis Research Campaign, said a treatment that stopped cartilage breakdown was the 'holy grail' for osteoarthritis researchers.
But he said there was no guarantee this would actually reduce pain.
'One of the complexities is that we're not sure whether the pain comes from the bone underlying the cartilage or inflammation in the tissue lining the joints.
'So we should be careful about thinking that a treatment that reduces cartilage loss will necessarily improve pain. But we all hope it will.'