title: Effects of trypsinization and mineralization on intrasynovial tendon allograft healing to bone.
abstract: The purpose of the current study was to develop a novel technology to enhance tendon-to-bone interface healing by trypsinizing and mineralizing (TM) an intrasynovial tendon allograft in a rabbit bone tunnel model. Eight rabbit flexor digitorum profundus (FDP) tendons were used to optimize the trypsinization process. An additional 24 FDP tendons were stratified into control and TM groups; in each group, 4 tendons were used for in vitro evaluation of TM and 8 were transplanted into proximal tibial bone tunnels in rabbits. The samples were evaluated histologically and with mechanical testing at postoperative week 8. Maximum failure strength and linear stiffness were not significantly different between the control and TM tendons. A thin fibrous band of scar tissue formed at the graft-to-bone interface in the control group. However, only the TM group showed obvious new bone formation inside the tendon graft and a visible fibrocartilage layer at the bone tunnel entrance. This study is the first to explore effects of TM on the intrasynovial allograft healing to a bone tunnel. TM showed beneficial effects on chondrogenesis, osteogenesis, and integration of the intrasynovial tendon graft, but mechanical strength was the same as the control tendons in this short-term in vivo study.
authors.affiliation: Division of Orthopedic Research, Mayo Clinic, Rochester, Minnesota.
authors.forename: Jin
authors.initials: J
authors.lastname: Qu
authors.forename: Nick A
authors.initials: NA
authors.lastname: van Alphen
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thoreson
authors.forename: Qingshan
authors.initials: Q
authors.lastname: Chen
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.forename: Peter C
authors.initials: PC
authors.lastname: Amadio
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Schmid
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhao
mesh_terms: D064591:Allografts; D000818:Animals; D001696:Biomechanical Phenomena; D002113:Calcification, Physiologic / Q000502:physiology*; D004548:Elasticity; D006023:Glycoproteins / Q000032:analysis; D066298:In Vitro Techniques; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery; D011817:Rabbits; D011897:Random Allocation; D019651:Plastic Surgery Procedures; D013710:Tendons / Q000737:chemistry / Q000473:pathology / Q000637:transplantation*; D013977:Tibia / Q000503:physiopathology* / Q000601:surgery; D014362:Trypsinogen / Q000494:pharmacology*; D014945:Wound Healing; D000099158:Proteoglycan 4
chemical_list: D006023:Glycoproteins; D014362:Trypsinogen; D000099158:Proteoglycan 4
keywords: intrasynovial tendon; mineralization; tendon-to-bone healing; trypsinization