Washington, Feb 23 : Researchers from Duke University Medical Centre have found certain vital clues to healing arthritis caused by traumatic injury.

They have identified a strain in laboratory mice that has "superhealing" powers, which can help resist inflammation after a knee injury, and avoid developing arthritis at the injury site in the long term.

"After a patient''s traumatic injury, orthopaedic surgeons realign the joint surface as anatomically as possible and then hope for the best," said Dr Steven A. Olson, FACS, principal investigator of the post-traumatic arthritis project and chief of the Duke orthopaedic trauma section.

"They haven''t been thinking about why patients with injuries are subsequently getting arthritis.

"Our research examines how we could possibly prevent arthritis development with growth factors and anti-inflammatory therapies after a fracture, either before or at the time of the surgery to fix it," he added.

The scientists examined the differences in inflammatory response between two types of mice: one type known as superhealers (or MRL/MpJ) versus a strain of control mice (C57BL/6).

Previous studies have shown that superhealer mice had such regenerative powers that holes made in their ears for lab identification purposes grew over completely with no sign of scar tissue.

"The superhealer can almost regenerate tissue," said Bridgette Furman, research analyst and lead scientist of this study.

"We thought, ''if they can regenerate cartilage in the ear, what about cartilage in the knee?'' This happened in our pilot study, and we now have taken these results further and learned what happens in terms of inflammation.

"If you can figure out why the animal is a superhealer and apply that to people, then you may help prevent the development of arthritis," Furman added.

During the study, the control mice showed a greater than 700-fold increase in the expression of one cytokine, interleukin(IL-1ß) in the first four hours after a fracture and
37-fold difference in that cytokine level at 7 days after the fracture.

Cytokines are signalling molecules produced by cells in response to injury. Interleukin generally promotes inflammation and an increase in temperature.

The superhealer mice showed a similar trend, but in much lower amounts.

The team also studied the mice''s joint fluid and blood serum to measure actual levels of the cytokines. Overall, the control mice again showed significantly higher serum levels and synovial (joint) fluid levels of cytokines compared with the superhealers.

The study was presented at the Orthopaedic Research Society meeting. (ANI)