Evaluation of glutaraldehyde-treated tendon xenograft

Glutaraldehyde-treated flexor tendon xenografts were implanted in 62 adult White Leghorn chickens. Animals were evaluated for implant integrity, function, mechanical tests, and histology serially to 24 weeks. Implant function improved dramatically throughout the 24 weeks. Gross examination at death showed intact proximal and distal attachments in all but two animals. The amount of fibrous ingrowth into the proximal end of the implant increased throughout the 24 weeks. Distal fibrous ingrowth also occurred, but at a slower rate. At no point was lateral ingrowth into the tendon seen within the fibro-osseous tunnel. Excision of the sheath and pulley system significantly limited tendon gliding by allowing vigorous formation of adhesions. Mechanical testing revealed that the distal attachment strengthened with time and that the proximal attachment became the failure point. Glutaraldehyde-treated mammalian tendon xenografts allow for fibrous ingrowth and may become incorporated by the host. In this animal model, it has allowed the xenograft to function as a tendon graft. Further studies are planned before clinical trials are undertaken.