title: Biomechanical properties of bovine tendon xenografts treated with a modern processing method.
abstract: Xenograft tendons have been used in few human studies, with variable results. With the advent of novel tissue processing techniques, which may mitigate against an immune-mediated rejection response without adversely affecting mechanical properties, there may now be a clinical role for xenograft tendons, particularly in knee ligament reconstruction. We hypothesize that 'BioCleanse®' processed bovine extensor digitorum medialis (EDM) tendons exhibit favorable time-zero pre-implantation biomechanical characteristics when compared to both unprocessed bovine EDM tendons and BioCleanse® processed human cadaveric allograft tibialis anterior tendons. In this in vitro case controlled laboratory study, three groups of tendons underwent a 5-stage static loading test protocol: 15 BioCleanse®bovine (BCB), 15 fresh frozen unprocessed bovine (FFB), and 12 BioCleanse®human allograft (BCA) tendons. Cross-sectional area of the grafts was measured using an alginate molding technique, and tendons were mounted within an Instron®5565 Materials Testing System using cryogenic clamps. BCB tendons displayed a higher ultimate tensile stress (p<0.05), with equivalent ultimate failure load, creep, and modulus of elasticity when compared to the FFB tendons (p>0.05). BCB tendons had an equivalent cross-sectional area to the BCA tendons (p>0.05) whilst exhibiting a greater failure load, ultimate tensile stress, less creep and a higher modulus of elasticity (p<0.05). The BioCleanse®process did not adversely affect the time-zero biomechanical properties of bovine xenograft EDM tendons. BioCleanse®processed bovine xenograft EDM tendons exhibited superior biomechanical characteristics when compared with BioCleanse®processed allograft tibialis anterior tendons. These findings support further investigation of xenograft tendons in orthopedic soft tissue reconstructive surgery.
authors.affiliation: Royal Free London NHS Foundation Trust, London, UK. Electronic address: henrycolaco@nhs.net.
authors.forename: Henry B
authors.initials: HB
authors.lastname: Colaço
authors.affiliation: Imperial College London, London, UK.
authors.forename: Breck R
authors.initials: BR
authors.lastname: Lord
authors.affiliation: Guy׳s and St Thomas׳ Hospital NHS Foundation Trust, London, UK.
authors.forename: Diane L
authors.initials: DL
authors.lastname: Back
authors.affiliation: Guy׳s and St Thomas׳ Hospital NHS Foundation Trust, London, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Davies
authors.affiliation: Imperial College London, London, UK.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Amis
authors.affiliation: Guy׳s and St Thomas׳ Hospital NHS Foundation Trust, London, UK.
authors.forename: Adil
authors.initials: A
authors.lastname: Ajuied
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D005615:Freezing; D064593:Heterografts; D008422:Materials Testing; D055595:Mechanical Phenomena; D013710:Tendons / Q000166:cytology* / Q000502:physiology
keywords: Biomechanics of tendon; Knee ligaments; Sterilization; Xenograft