We call it a ‘dicky knee’ because osteoarthritis is too depressing to talk about.

But there it is: the cartilage in the knee joint is worn or torn, inflammation sets in, and you take pain killers and limp through with gritted teeth until a knee replacement is unavoidable.

Because joint prosthetics have limited durability, and eventually need to be replaced, it’s far from an ideal solution, especially in younger patients.

Now, Swiss researchers believe they’ve found a possible alternative.

In experiments in animals and two humans, scientists from the University Hospital of Basel, cultivated cartilage cells taken from the patient’s nasal septum and used them to grow a cartilage layer that was then surgically implanted into the knee joint.

In the operating theatre, the graft was tailored to the shape and size of the cartilage defect in the knee.

Grafted cartilage countered inflammation

The researchers found that these grafts didn’t simply repair cartilage injuries in the knee, they also withstood “the chronic inflammatory tissue environment in osteoarthritis and even counteract the inflammation”.

This became apparent during experiments on sheep: the crippling inflammation of osteoarthritis was reportedly tamed.

Following successful trials on animals, the researchers tested the grafting strategy “on two young patients suffering from severe osteoarthritis, likely due to misalignment of the leg bones”.

The alternative treatment would have been a knee joint prosthesis.

Human study results

According to a statement from the University of Basel, “following the implantation of the graft, the two patients reported a reduction in pain and increased quality of life”.

In one of the two patients, “researchers were also able to determine via MRI images that the bones in the knee joint were further apart than previously – an indication of the joint’s recovery”, the statement said.

Pandemic restrictions meant the researchers were unable to perform MRI scans on the second patient, and “could only interview him to derive a subjective assessment”.

The researchers reported that “the misalignment of the bones in both patients could be surgically corrected and thus the most likely cause of their osteoarthritis eliminated, the researchers are confident that patients will be able to manage without knee joint prostheses, at least for some time”.

“Our results have enabled us to lay the biological foundation for a therapy, and we are cautiously optimistic” said University Hospital Basel professor Ivan Martin.

Professor Martin is the corresponding author of the new paper.

The key to the procedure’s success, the authors said, was the “amazing properties of the nasal cartilage”.

Nasal cartilage are different to cartilage tissue in the joints: the nasal cells originate from precursor cells of what’s known as the neuroectoderm.

These are the layer of cells in early embryonic development that develop into the brain and spinal cord, and which have “a distinct regenerative and adaptive capacity” or plasticity.

“Tissue grown from nasal cartilage cells seems also to retain these special properties,” said Professor Martin.