Advertisement

Biocompatibility of three-dimensional chondrocyte grafts in large tibial defects of rabbits

James L. CookComparative Orthopaedic Laboratory, University of Missouri, 379 E Campus Dr, Columbia, MO 65211.

Search for other papers by James L. Cook in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
Ned WilliamsComparative Orthopaedic Laboratory, University of Missouri, 379 E Campus Dr, Columbia, MO 65211.
Current address is Eastern Carolina Veterinary Referral, 5333 Oleander Dr, Wilmington, NC 28403.

Search for other papers by Ned Williams in
Current site
Google Scholar
PubMed
Close
 DVM
,
John M. KreegerComparative Orthopaedic Laboratory, University of Missouri, 379 E Campus Dr, Columbia, MO 65211.

Search for other papers by John M. Kreeger in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
John T. PeacockComparative Orthopaedic Laboratory, University of Missouri, 379 E Campus Dr, Columbia, MO 65211.
Current address is South Texas Veterinary Specialists, 8503 Broadway, San Antonio, TX 78217.

Search for other papers by John T. Peacock in
Current site
Google Scholar
PubMed
Close
 DVM
, and
James L. TomlinsonComparative Orthopaedic Laboratory, University of Missouri, 379 E Campus Dr, Columbia, MO 65211.

Search for other papers by James L. Tomlinson in
Current site
Google Scholar
PubMed
Close
 DVM, MVSc

Abstract

Objective—To evaluate biocompatibility and effects of implantation of 3-dimensional chondrocyte-agarose autografts in tibial defects in rabbits and to compare in vitro and in vivo chondrocyte-agarose constructs with respect to cell viability, differentiation, and matrix production.

Animals—24 adult New Zealand White rabbits.

Procedure—Three-dimensional constructs with (grafted group) or without (control group) autogenous chondrocytes were implanted into tibial defects of rabbits and cultured in vitro. During an 8-week period, defects were evaluated radiographically, grossly, histologically, biochemically, and immunohistochemically. In vitro constructs were evaluated histologically, biochemically, and immunohistochemically.

Results—Tibial defects had significantly higher radiographic densitometry values at 4 and 6 weeks after implantation in grafted group rabbits, compared with control group rabbits. Number of observed centers of endochondral ossification was significantly greater in defects of grafted group rabbits, compared with control group rabbits. On day 14, glycosaminoglycan concentration was significantly higher in tibial defects of grafted group rabbits, compared to defects of control group rabbits or in vitro constructs. At weeks 2, 4, and 8, glycosaminoglycan concentrations were significantly lower in the in vitro control constructs, compared with other groups. Collagen type I was present in bone and bony callous in defects of grafted and control group rabbits. Collagen type II was identified in cartilaginous tissues of grafted and control group rabbits. Collagen type X was associated with hypertrophic chondrocytes. Only type II collagen was found in the in vitro chondrocyte constructs.

Conclusion and Clinical Relevance—Chondrocyte-agarose grafts are biocompatible in large tibial defects and appear to provide a cell source for augmenting endochondral ossification. (Am J Vet Res 2003;64:12–20)

Abstract

Objective—To evaluate biocompatibility and effects of implantation of 3-dimensional chondrocyte-agarose autografts in tibial defects in rabbits and to compare in vitro and in vivo chondrocyte-agarose constructs with respect to cell viability, differentiation, and matrix production.

Animals—24 adult New Zealand White rabbits.

Procedure—Three-dimensional constructs with (grafted group) or without (control group) autogenous chondrocytes were implanted into tibial defects of rabbits and cultured in vitro. During an 8-week period, defects were evaluated radiographically, grossly, histologically, biochemically, and immunohistochemically. In vitro constructs were evaluated histologically, biochemically, and immunohistochemically.

Results—Tibial defects had significantly higher radiographic densitometry values at 4 and 6 weeks after implantation in grafted group rabbits, compared with control group rabbits. Number of observed centers of endochondral ossification was significantly greater in defects of grafted group rabbits, compared with control group rabbits. On day 14, glycosaminoglycan concentration was significantly higher in tibial defects of grafted group rabbits, compared to defects of control group rabbits or in vitro constructs. At weeks 2, 4, and 8, glycosaminoglycan concentrations were significantly lower in the in vitro control constructs, compared with other groups. Collagen type I was present in bone and bony callous in defects of grafted and control group rabbits. Collagen type II was identified in cartilaginous tissues of grafted and control group rabbits. Collagen type X was associated with hypertrophic chondrocytes. Only type II collagen was found in the in vitro chondrocyte constructs.

Conclusion and Clinical Relevance—Chondrocyte-agarose grafts are biocompatible in large tibial defects and appear to provide a cell source for augmenting endochondral ossification. (Am J Vet Res 2003;64:12–20)