title: A novel silk-based artificial ligament and tricalcium phosphate/polyether ether ketone anchor for anterior cruciate ligament reconstruction - safety and efficacy in a porcine model.
abstract: Loss of ligament graft tension in early postoperative stages following anterior cruciate ligament (ACL) reconstruction can come from a variety of factors, with slow graft integration to bone being widely viewed as a chief culprit. Toward an off-the-shelf ACL graft that can rapidly integrate to host tissue, we have developed a silk-based ACL graft combined with a tricalcium phosphate (TCP)/polyether ether ketone anchor. In the present study we tested the safety and efficacy of this concept in a porcine model, with postoperative assessments at 3months (n=10) and 6months (n=4). Biomechanical tests were performed after euthanization, with ultimate tensile strengths at 3months of ∼370N and at 6months of ∼566N - comparable to autograft and allograft performance in this animal model. Comprehensive histological observations revealed that TCP substantially enhanced silk graft to bone attachment. Interdigitation of soft and hard tissues was observed, with regenerated fibrocartilage characterizing a transitional zone from silk graft to bone that was similar to native ligament bone attachments. We conclude that both initial stability and robust long-term biological attachment were consistently achieved using the tested construct, supporting a large potential for silk-TCP combinations in the repair of the torn ACL.
authors.affiliation: Department of Orthopaedics, Balgrist University Hospital, Zurich, Switzerland; Department Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Lab for Manufacturing System Engineering, Xi'an Jiaotong University, People's Republic of China.
authors.forename: Jiankang
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Orthopaedics Surgery, First Hospital of Xi'an Jiaotong University, People's Republic of China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Bian
authors.affiliation: Department of Orthopaedics Surgery, Tangdu Hospital of Fourth Military Medical University, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Lab for Manufacturing System Engineering, Xi'an Jiaotong University, People's Republic of China.
authors.forename: Wenyou
authors.initials: W
authors.lastname: Zhang
authors.affiliation: State Key Lab for Manufacturing System Engineering, Xi'an Jiaotong University, People's Republic of China.
authors.forename: Dichen
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Balgrist University Hospital, Zurich, Switzerland; Department Health Sciences and Technology, ETH Zurich, Zurich, Switzerland. Electronic address: snedeker@ethz.ch.
authors.forename: Jess G
authors.initials: JG
authors.lastname: Snedeker
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000254:growth & development* / Q000473:pathology; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation* / Q000379:methods; D001577:Benzophenones; D001705:Bioprosthesis; D002130:Calcium Phosphates / Q000737:chemistry; D019544:Equipment Failure Analysis; D048091:Guided Tissue Regeneration / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007659:Ketones / Q000737:chemistry; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers; D011474:Prosthesis Design; D047011:Silk / Q000737:chemistry*; D013552:Swine; D054457:Tissue Scaffolds; D016896:Treatment Outcome
chemical_list: D001577:Benzophenones; D002130:Calcium Phosphates; D007659:Ketones; D011108:Polymers; D047011:Silk; C063834:polyetheretherketone; D011092:Polyethylene Glycols; C018392:tricalcium phosphate
keywords: ACL reconstruction; Artificial ACL; PEEK; Silk; TCP