Search

Collagenous xenografts made from kangaroo tail tendon cross-linked with glutaraldehyde have a potential application in the reconstruction of massive digital tendon deficits. However, a limitation to the clinical use of these xenografts has been the optimization of collagen cross-linking, and subsequent bio-incorporation and retention of mechanical properties following implantation. The purpose of this study was to evaluate the effect of nitrous acid on modulating the biologic and mechanical properties of tendon xenografts cross-linked with glutaraldehyde. Tendon xenografts were pretreated with 0.1 or 0.01 M nitrous acid solution, prior to cross-linking in 2% glutaraldehyde and sterilization by gamma irradiation. Xenografts were implanted intramuscularly in rabbits to examine biocompatability, and also used to repair ovine digital extensor tendon deficits to evaluate functional incorporation. Histologically, intramuscularly implanted nitrous acid pretreated xenografts in rabbits had a greater degree of diffuse cellular infiltration into interstitial splits in the graft than controls after 12 weeks. Xenografts implanted in an ovine extensor tendon deficit were evaluated after 26 and 52 weeks. Rate of failure of tenorrhaphies between host tendon and xenografts overall (15/21) was significantly greater (P < 0.05) than for autografts (1/21), suggesting that the holding power of sutures in xenografts was inferior to that obtained in autografts. Tensile failure stress of midsections of both nitrous acid pretreated and control xenografts was about 100 MPa prior to implantation (time zero). After 26 and 52 weeks, failure stress of both types of xenografts was significantly less than at time zero (P < 0.05). At 52 weeks, failure stress of nitrous acid pretreated xenografts (47.4 ± 3.1 MPa) was significantly less than control xenografts (63.7 ± 5.4 MPa); (P < 0.05). However, nitrous acid pretreated xenografts were similar to control xenografts in failure load (357 ± 29 and 354

Collagenous xenografts made from kangaroo tail tendon cross-linked with glutaraldehyde have a potential application in the reconstruction of massive digital tendon deficits. However, a limitation to the clinical use of these xenografts has been the optimization of collagen cross-linking, and subsequent bio-incorporation and retention of mechanical properties following implantation. The purpose of this study was to evaluate the effect of nitrous acid on modulating the biologic and mechanical properties of tendon xenografts cross-linked with glutaraldehyde. Tendon xenografts were pretreated with 0.1 or 0.01 M nitrous acid solution, prior to cross-linking in 2% glutaraldehyde and sterilization by gamma irradiation. Xenografts were implanted intramuscularly in rabbits to examine biocompatability, and also used to repair ovine digital extensor tendon deficits to evaluate functional incorporation. Histologically, intramuscularly implanted nitrous acid pretreated xenografts in rabbits had a greater degree of diffuse cellular infiltration into interstitial splits in the graft than controls after 12 weeks. Xenografts implanted in an ovine extensor tendon deficit were evaluated after 26 and 52 weeks. Rate of failure of tenorrhaphies between host tendon and xenografts overall (15/21) was significantly greater (P < 0.05) than for autografts (1/21), suggesting that the holding power of sutures in xenografts was inferior to that obtained in autografts. Tensile failure stress of midsections of both nitrous acid pretreated and control xenografts was about 100 MPa prior to implantation (time zero). After 26 and 52 weeks, failure stress of both types of xenografts was significantly less than at time zero (P < 0.05). At 52 weeks, failure stress of nitrous acid pretreated xenografts (47.4 ± 3.1 MPa) was significantly less than control xenografts (63.7 ± 5.4 MPa); (P < 0.05). However, nitrous acid pretreated xenografts were similar to control xenografts in failure load (357 ± 29 and 354