Stem cell technique could help avert hip replacement

Arthritis sufferers have been offered new hope after scientists grew a "living hip" in the laboratory, in a development that could mean that the increasing number of people suffering osteoarthritis could avoid or delay undergoing hip surgery in the future.

The researchers in the United States used stem cells to grow cartilage in the exact shape of a hip joint, while also genetically engineering the tissue to release anti-inflammatory molecules to fend off the return of arthritis.

The breakthrough has great potential for patients who suffer from osteoarthritis, the most common form of the disease in many geographies, which affects people as they get older. This form of arthritis causes the cartilage to roughen and become thinner.

If this new stem-cell development is successful, over time it would mean that sufferers could avoid or delay hip surgery.

Commenting on the development Maurice Neligan, director of orthopaedic surgery at the Beacon Hospital in Dublin, who was not connected with the research, told The Irish Independent stem cell research held out huge hope for improvements in these kind of treatments.

However, he cautioned, "It could be 20 to 30 years before patients will see the benefit."

Tests on human patients with this 'living hip' will begin in five years.

The researchers at Washington University said the cartilage was implanted around the joint in order to extend its life when arthritis had caused too much damage to the bone.

Severe loss of cartilage can lead to bone rubbing on bone, altering the shape of the joint and forcing the bones out of their normal position.

Many patients so far have no option but to have a hip replacement with metal prosthetics. However, younger patients are often told to wait until the age of 50 for surgery as current prosthetics only last for up to 20 years.

The surgery to replace them risks further bone damage and infection.

Dr Farshid Guilak, professor of orthopaedic surgery at Washington University, said, "We have now developed a way to resurface an arthritic joint, using a patient's own stem cells to grow new cartilage, combined with gene therapy to release anti-inflammatory molecules to keep arthritis at bay.

"Our hope is to prevent, or at least delay, a standard metal and plastic prosthetic joint replacement."

The technique uses a 3-D, biodegradable synthetic scaffold, which is moulded into the precise shape of a patient's joint and then covered with stem cells taken from fat beneath the skin.

The scaffold is built using a weaving pattern that allows the stem cells to transform into the structure and shape of normal cartilage.

Because the implant is made from a patient's own stem cells, there is no risk of rejection.

The scientists have genetically engineered the cartilage to release anti-inflammatory molecules when the patient takes a drug.

"When there is inflammation, we can give a patient a simple drug, which activates the gene that we have implanted, in order to lower inflammation in the joint," said Dr Guilak, also a professor of developmental biology and of biomedical engineering.

The ground-breaking research was published in the professional journal Proceedings of the National Academy of Sciences.