JOINT RESURFACING USING ALLOGRAFT CHONDROCYTES AND SYNTHETIC BIODEGRADABLE POLYMER SCAFFOLDS

Cartilage implants which could potentially be used to resurface damage d joints were created using rabbit articular chondrocytes and syntheti c, biodegradable polymer scaffolds. Cells were serially passaged and t hen cultured in vitro on fibrous polyglycolic acid (PGA) scaffolds. Ce ll-PGA constructs were implanted in vivo as allografts to repair 3-mm diameter, full thickness defects in the knee joints of adult rabbits, and cartilage repair was assessed histologically over 6 months. In vit ro, chondrocytes proliferated on PGA and regenerated cartilaginous mat rix. Collagen and glycosaminoglycan (GAG) represented 20 to 8% of the implant dry weight (dw), respectively, at the time of in vivo implanta tion; the remainder was PGA and unspecified components. implants based on passaged chondrocytes had 1.7-times as much GAG and 2.6-times as m uch collagen as those based on primary chondrocytes. In vivo, cartilag inous repair tissue was observed after implantation of PGA both with a nd without cultured chondrocytes. Six month repair was qualitatively b etter for cell-PGA allografts than for PGA alone, with respect to: 1) surface smoothness, 2) columnar alignment of chondrocytes, 3) spatiall y uniform GAG distribution, 4) reconstitution of the subchondral plate , and 5) bonding of the repair tissue to the underlying bone. These pi lot studies demonstrate that it is feasible to use cell-polymer allogr afts for joint resurfacing in vivo. (C) 1994 John Wiley and Sons, Inc.