Original Article| Volume 29, ISSUE 6, P1079-1088, June 2013

Biological and Biomechanical Evaluation of the Ligament Advanced Reinforcement System (LARS AC) in a Sheep Model of Anterior Cruciate Ligament Replacement: A 3-Month and 12-Month Study


      The purposes of this study were to assess tissue ingrowth within the Ligament Advanced Reinforcement System (LARS) artificial ligament (LARS AC; LARS, Arc sur Tille, France) and to study the biomechanical characteristics of the reconstructed knees in a sheep model of anterior cruciate ligament (ACL) replacement.


      Twenty-five female sheep underwent excision of the proximal third of the left ACL and intra-articular joint stabilization with a 44-strand polyethylene terephthalate ligament (mean ultimate tensile failure load, 2,500 N). Animals were killed either 3 or 12 months after surgery. Explanted knees were processed for histology (n = 10) or mechanical tests including tests of laxity and loading to failure in tension (n = 15).


      Well-vascularized tissue ingrowth within the artificial ligament was only observed in the portions of the ligament in contact with the host's tissues (native ligament and bone tunnels). Ligament wear was observed in 40% of explanted knees. The ultimate tensile failure loads of the operated knees at both time points were inferior to those of the contralateral, intact knees (144 ± 69 N at 3 months and 260 ± 126 N at 12 months versus 1,241 ± 270 N and 1,218 ± 189 N, respectively) (P < .01). In specimens with intact artificial ligaments, failure occurred by slippage from the bone tunnels in all specimens explanted 3 months postoperatively and in half of the specimens explanted 12 months postoperatively.


      This study provides evidence that the LARS AC has a satisfactory biointegration but that it is not suitable for ACL replacement if uniform tissue ingrowth is contemplated. Despite good clinical performance up to 1 year after implantation, none of the reconstructions approached the mechanical performance of the normal ACL in the ovine model. Partial tearing of the artificial ligament, which led to a significant decrease in ultimate tensile strength, was observed in 40% of cases in the ovine model.

      Clinical Relevance

      The LARS is not a suitable scaffold for ACL replacement. Further animal studies are needed to evaluate its potential for augmentation of ligament repair.
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        • Murray A.W.
        • MacNicol M.F.
        10-16 Year results of Leeds-Keio anterior cruciate ligament reconstruction.
        Knee. 2004; 11: 9-14
        • Jadeja H.
        • Yeoh D.
        • Lal M.
        • Mowbray M.
        Patterns of failure with time of an artificial scaffold class ligament used for reconstruction of the human anterior cruciate ligament.
        Knee. 2007; 14: 439-442
        • Poddevin N.
        • King M.W.
        • Guidoin R.G.
        Failure mechanisms of anterior cruciate ligament prostheses: In vitro wear study.
        J Biomed Mater Res. 1997; 38: 370-381
        • Guidoin M.F.
        • Marois Y.
        • Bejui J.
        • Poddevin N.
        • King M.W.
        • Guidoin R.
        Analysis of retrieved polymer fiber based replacements for the ACL.
        Biomaterials. 2000; 21: 2461-2474
        • Lavoie P.
        • Fletcher J.
        • Duval N.
        Patient satisfaction needs as related to knee stability and objective findings after ACL reconstruction using the LARS artificial ligament.
        Knee. 2000; 7: 157-163
        • Mascarenhas R.
        • MacDonald P.B.
        Anterior cruciate ligament reconstruction: A look at prosthetics—Past, present and possible future.
        McGill J Med. 2008; 11: 29-37
        • Lavoie P.
        • Duval N.
        A new generation of artificial ligaments in reconstruction of the anterior cruciate ligament: Two-year follow-up of randomized trial.
        J Bone Joint Surg Br. 2002; 84: 356-360
        • Gao K.
        • Chen S.
        • Wang L.
        • et al.
        Anterior cruciate ligament reconstruction with LARS artificial ligament: A multicenter study with 3- to 5-year follow-up.
        Arthroscopy. 2010; 26: 515-523
        • Liu Z.T.
        • Zhang X.L.
        • Jiang Y.
        • Zeng B.F.
        Four-strand hamstring tendon autograft versus LARS artificial ligament for anterior cruciate ligament reconstruction.
        Int Orthop. 2010; 34: 45-49
        • Ranger P.
        • Renaud A.
        • Phan P.
        • Dahan P.
        • De Oliveira Jr., E.
        • Delisle J.
        Evaluation of reconstructive surgery using artificial ligaments in 71 acute knee dislocations.
        Int Orthop. 2011; 35: 1477-1482
        • Mulford J.S.
        • Chen D.
        Anterior cruciate ligament reconstruction: A systematic review of polyethylene terephthalate grafts.
        ANZ J Surg. 2011; 81: 785-789
        • Trieb K.
        • Blahovec H.
        • Brand G.
        • Sabeti M.
        • Dominkus M.
        • Kotz R.
        In vivo and in vitro cellular ingrowth into a new generation of artificial ligaments.
        Eur Surg Res. 2004; 36: 148-151
        • Glezos C.M.
        • Waller A.
        • Bourke H.E.
        • Salmon L.J.
        • Pinczewski L.A.
        Disabling synovitis associated with LARS artificial ligament use in anterior cruciate ligament reconstruction: A case report.
        Am J Sports Med. 2012; 40: 1167-1171
        • Li H.
        • Yao Z.
        • Jiang J.
        • et al.
        Biologic failure of a ligament advanced reinforcement system artificial ligament in anterior cruciate ligament reconstruction: A report of serious knee synovitis.
        Arthroscopy. 2012; 28: 583-586
        • Newman S.D.
        • Atkinson H.D.
        • Willis-Owen C.A.
        Anterior cruciate ligament reconstruction with the ligament augmentation and reconstruction system: A systematic review.
        Int Orthop. 2013; 37: 321-326
        • Smith L.
        • Xia Y.
        • Galatz L.M.
        • Genin G.M.
        • Thomopoulos S.
        Tissue engineering strategies for tendon to bone interface.
        Connect Tissue Res. 2011; 53: 95-105
        • Liu Y.
        • Birman V.
        • Chen C.
        • Thomopoulos S.
        • Genin G.M.
        Mechanisms of biomaterial attachment at the interface of tendon to bone.
        J Eng Mater Technol. 2011; : 133
        • Robbe R.
        • Johnson D.
        Graft fixation alternatives in anterior cruciate ligament reconstruction.
        Penn Orthop J. 2002; 15: 21-27
        • Hunt P.
        • Scheffler S.U.
        • Unterhauser F.N.
        • Weiler A.
        A model of soft-tissue graft anterior cruciate ligament reconstruction in sheep.
        Arch Orthop Trauma Surg. 2005; 125: 238-248
        • Machotka Z.
        • Scarborough I.
        • Duncan W.
        • Kumar S.
        • Perraton L.
        Anterior cruciate ligament repair with LARS (ligament advanced reinforcement system): A systematic review.
        Sports Med Arthrosc Rehabil Ther Technol. 2010; 2: 29-39
        • Schindhelm K.
        • Rogers G.J.
        • Milthorpe B.K.
        • et al.
        Autograft and Leeds-Keio reconstructions of the ovine anterior cruciate ligament.
        Clin Orthop Relat Res. 1991; : 278-293
        • Dürselen L.
        • Häfner M.
        • Ignatius A.
        • et al.
        Biological response to a new composite polymer augmentation device used for cruciate ligament reconstruction.
        J App Mat Res Part B. 2006; 76: 265-272
        • Dürselen L.
        • Claes L.
        • Ignatius A.
        • Rübenacker S.
        Comparative animal study of three ligament prostheses for the replacement of the anterior cruciate and medial collateral ligament.
        Biomaterials. 1996; 17: 977-982
        • Ferkel R.D.
        • Fox J.M.
        • Wood D.
        • Del Pizzo W.
        • Friedman M.J.
        • Snyder S.J.
        Arthroscopic “second look” at the GORE-TEX ligament.
        Am J Sports Med. 1989; 17: 147-152
        • Ventura A.
        • Terzaghi C.
        • Legnani C.
        • Borgo E.
        • Albisetti W.
        Synthetic grafts for anterior cruciate ligament rupture: 19-Year outcome study.
        Knee. 2010; 17: 108-113
        • Taylor W.R.
        • Ehrig R.M.
        • Heller M.O.
        • Schell H.
        • Seebeck P.
        • Duda G.N.
        Tibio-femoral joint contact forces in sheep.
        J Biomech. 2006; 39: 791-798
        • Osterhoff G.
        • Löffler S.
        • Steinke H.
        • Feja C.
        • Josten C.
        • Hepp P.
        Comparative anatomical measurements of osseous structures in the ovine and human.
        Knee. 2011; 18: 98-103
        • Laboureau J.
        • Marnat-Perrichet F.P.
        Isometric reconstruction of the anterior cruciate ligament. Determination of the femoral and tibial tunnels.
        Acta Orthop Belg. 1996; 62: 166-177
        • Weiler A.
        • Hoffmann R.F.
        • Bail H.J.
        • Rehm O.
        • Südkamp N.P.
        Tendon healing in a bone tunnel. Part II: Histologic analysis after biodegradable interference fit fixation in a model of anterior cruciate ligament reconstruction in sheep.
        Arthroscopy. 2002; 18: 124-135