Bioengineered cartilage repairs damaged knees

NEW YORK (Reuters Health) - Implanting bioengineered cartilage in damaged knee joints can regenerate tissue lining the joints, according to a new study.

Dr. Anthony P. Hollander from University of Bristol and associates in the UK and in Italy investigated the maturation of bioengineered cartilage (Hyalograft C) implanted into 23 patients

Knee damage had been caused by injury or through osteoarthritis -- the wear-and-tear form of arthritis, rather than rheumatoid arthritis that results from an abnormal immune reaction.

Biopsies were performed between 6 and 30 months after implantation. Ten patients showed normal distribution of cartilage cells while ten had an abnormal cell organization, the researchers report in the journal Tissue Engineering. Three biopsies showed features of both fibrocartilage and normal hyaline tissue -- the smooth, pearly form of cartilage that covers the surfaces of joints.

All of the normal hyaline biopsies showed that the defect repair was level with the surrounding cartilage, the investigators report.

All biopsies also showed close integration of the cartilage with the underlying bone, the team notes, whether the repair tissue was hyaline or fibrocartilage.

The quality of the hyaline cartilage repair tissue was better in osteoarthritic knees than in non-osteoarthritic knees, the investigators noted.

"We have shown for the first time that tissue-engineered cartilage implanted into knees can mature into an articular cartilage structure as early as 11 months after implantation of Hyalograft C," the Hollander and colleagues conclude. "Development of osteoarthrosis, far from inhibiting articular cartilage formation, appeared to enhance the maturation process."

SOURCE: Tissue Engineering, July 2006.