New Gel-Based Artificial Cartilage Might Eliminate the Need for Total Knee Replacement

Knee pain is one of the most rampant health issues for many. This pain stems from the wear and tear of the cartilage in a medical condition called osteoarthritis. Seeking relief, people commonly turn to steroid injections, pain relievers, physical therapies, or getting their knee joint replaced. But, a new development might prove to be a game changer. Researchers from Duke University have created the first gel-based substitute for natural cartilage, which, according to them, is more durable than the original. The hydrogel material is made of water and absorbing materials, and can effectively resist wear and tear up to three times more than the natural cartilage.

To develop the material, the team infused thin sheets of cellulose fibres with a polymer named polyvinyl alcohol and create a gel. The polymer has a viscous gum-like consistency and has stringy chains of repeating molecules.

The cellulose mimics the function of the collagen fibres in natural cartilage and provides strength to the gel when it is stretched. The polyvinyl alcohol, meanwhile, helps the gel regain its original shape. With these properties, a Jello-like material was created that has 60 percent water but still offers great strength.

Testing revealed that the material was even stronger than the natural cartilage. Our cartilage can resist 5,800 pounds of tugging and 8,500 pounds of squishing. However, the artificial cartilage proved to be 26 percent stronger in tension and 66 percent stronger in terms of compression than the natural cartilage.

"It's really off the charts in terms of hydrogel strength,” said Duke University's professor Benjamin Wiley. He is the lead author of the study published in Advanced Functional Materials.

The team had developed the hydrogel in 2020 but has now put it to practical use as artificial cartilage. With the massive strength of the cartilage, researchers faced challenges trying to secure it to the joint. For this, they cemented and clamped the hydrogel on a titanium base which was then pressed and anchored into a hole in the place of the damaged cartilage. This helped them maintain the cartilage in place.

According to Wiley, artificial cartilage is better than going for a total knee replacement. He said artificial joints require major surgery to be implanted and need to be replaced later. Talking of the new material, he added, “I think this will be a dramatic change in treatment for people at this stage.” Researchers are now looking forward to the clinical trials of artificial cartilage.