New York, Dec 11 (IANS): People having a torn protective lining in the knee, which is known as meniscus, may soon have a personalised 3D-printed implant to regenerate the lining on its own.

The therapy, successfully tested in sheep (whose knee closely resembles that of humans), could provide the first effective and long-lasting repair of damaged menisci that can lead to debilitating arthritis.

"At present, there is little that orthopaedists can do to regenerate a torn knee meniscus," said study leader Jeremy Mao from Columbia University's medical centre.

The new approach starts with MRI scans of the intact meniscus in the undamaged knee. The scans are converted into a 3D image.

Data from the image are then used to drive a 3D printer, which produces a scaffold in the exact shape of the meniscus.

The scaffold, which takes about 30 minutes to print, is infused with two human proteins: connective growth factor (CTGF) and transforming growth factor I3 (TGFI3).

Finally, the protein-infused scaffold is inserted into the knee.

In sheep, the meniscus regenerates in about four to six weeks. Eventually, the scaffold dissolves and is eliminated by the body.

The process was tested in 11 sheep. In a postmortem analysis, the researchers found that the regenerated meniscus in the treatment group had structural and mechanical properties very similar to those of natural meniscus.

"We envision that personalised meniscus scaffolds from initial MRI to 3D printing could be completed within days," said Mao.

The researchers hope to begin clinical trials once funding is in place.

The study appeared online in the journal Science Translational Medicine.