A NOVEL SOURCE OF CELLS FOR AUTOLOGOUS CHONDROCYTE IMPLANTATION IN THE YOUNG ADULT KNEE

Abstract

Autologous Chondrocyte Implantation (ACI) is a technique for repair of isolated symptomatic articular cartilage defects in the young adult knee. The knee is arthroscopically assessed and a sample of cartilage is harvested from the margin of the joint, this is digested and the liberated chondrocytes expanded in culture. At subsequent arthrotomy, the articular cartilage lesion is debrided and the cells injected behind a sutured flap. A concern regarding ACI is the iatrogenic insult to non-injured healthy cartilage adjacent to that harvested for culture.

Damaged cartilage around the lesion is routinely debrided and discarded at the second stage operation. The purpose of this study was to determine whether this damaged debrided cartilage could yield an adequate number of equivalent chondrocytes for ACL.

Cells from 11 patients were analysed. The debrided “waste” from around the lesion was collected, enzymatically digested and the liberated chondrocytes cultured in monolayer.

The cells were recovered and placed in a 3D-pellet culture in a defined medium.

Chondrocytes obtained from the routine harvest of healthy cartilage were placed in a similar culture system. The two groups were compared using DNA and GAG assays, histological and immunohistochemical techniques.

Chondrocytes obtained from the debrided cartilage lesion were equivalent to those obtained from the harvested healthy cartilage. Sufficient cell numbers for implantation were achieved for all patients, however cells cultured from the debrided defect in patients who had a large degenerate lesion required significantly longer in culture to attain the required number of cells.

For many patients undergoing ACI, the potential iatrogenic insult to the joint cartilage of the harvesting procedure could be avoided by harvesting the damaged tissue from around the defect itself.