Newly grown engineered cartilage in sight

A group of biomedical engineering researchers have cited recent advances in implantable sensor technology and cartilage scaffolding systems as major developments in the use of engineered cartilage for bone and joint repair.

These advances could mean help for the vast number of patients suffering from damaged joints and osteoarthritis -- the most common form of arthritis that affects millions of people worldwide.

Newer, smaller sensing devices that more accurately measure stress loads on joints are giving researchers testing newly grown engineered cartilage within a joint a better understanding of the healing process. Armed with these data, doctors could advise patients on safer, more beneficial levels of activity following joint surgery.

The sensors also transmit their measurements wirelessly, enabling patients undergoing cartilage growth therapy to monitor their own joint stress loads in real time.

The advances appear this month in the Journal of the American Academy of Orthopaedic Surgeons.

Accurately measuring the loads within a repaired joint helps determine smarter ways to get joints to heal, said article co-author John Szivek, professor in the department of orthopaedic surgery at the University of Arizona and director of the UA Orthopedic Research Laboratory in Tucson, Ariz. Szivek also chairs the UA Biomedical Engineering Graduate Interdisciplinary Program.

Szivek said he's been published with a very elite group of researchers in this particular area of biomedical engineering. "There are only a handful of research groups in the world doing this type of work, and my lab is the only one in the world collecting direct measurements from native tissues," he said.

The group is a collaboration of researchers from four universities. Co-authors Ledet and Wachs are from the department of biomedical engineering at Rensselaer Polytechnic Institute in Troy, N.Y. D’Lima is from the department of molecular and experimental medicine at the Scripps Research Institute in La Jolla, Calif., and Westerhoff and Bergmann are from the Julius Wolff Institut, Charité University of Medicine, Berlin, Germany.

"It’s a stroke of genius to combine tissue engineering and improved implant measurement technology," said Jennifer Barton, head of the UA biomedical engineering department. "No one really knew what the specific loads were on these joints before this," she said.

Monitoring and recording the pressures involved in different patient activities decreases rehabilitation time and allows patients to heal more consistently without damaging themselves during rehab or after they have healed. Szivek said the ultimate goal is to house the transmitters on a single small computer chip about one third the size of a dime. These new chip-based transmitters would wirelessly transmit patient activity, including reporting the recent history of various loads on a repaired joint. Patients could also moniFootwear