Purpose
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.
Methods
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).
Results
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.
Conclusions
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.
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to ArthroscopyAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- 10-16 Year results of Leeds-Keio anterior cruciate ligament reconstruction.Knee. 2004; 11: 9-14
- 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
- Failure mechanisms of anterior cruciate ligament prostheses: In vitro wear study.J Biomed Mater Res. 1997; 38: 370-381
- Analysis of retrieved polymer fiber based replacements for the ACL.Biomaterials. 2000; 21: 2461-2474
- Patient satisfaction needs as related to knee stability and objective findings after ACL reconstruction using the LARS artificial ligament.Knee. 2000; 7: 157-163
- Anterior cruciate ligament reconstruction: A look at prosthetics—Past, present and possible future.McGill J Med. 2008; 11: 29-37
- 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
- Anterior cruciate ligament reconstruction with LARS artificial ligament: A multicenter study with 3- to 5-year follow-up.Arthroscopy. 2010; 26: 515-523
- Four-strand hamstring tendon autograft versus LARS artificial ligament for anterior cruciate ligament reconstruction.Int Orthop. 2010; 34: 45-49
- Evaluation of reconstructive surgery using artificial ligaments in 71 acute knee dislocations.Int Orthop. 2011; 35: 1477-1482
- Anterior cruciate ligament reconstruction: A systematic review of polyethylene terephthalate grafts.ANZ J Surg. 2011; 81: 785-789
- In vivo and in vitro cellular ingrowth into a new generation of artificial ligaments.Eur Surg Res. 2004; 36: 148-151
- Disabling synovitis associated with LARS artificial ligament use in anterior cruciate ligament reconstruction: A case report.Am J Sports Med. 2012; 40: 1167-1171
- 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
- Anterior cruciate ligament reconstruction with the ligament augmentation and reconstruction system: A systematic review.Int Orthop. 2013; 37: 321-326
- Tissue engineering strategies for tendon to bone interface.Connect Tissue Res. 2011; 53: 95-105
- Mechanisms of biomaterial attachment at the interface of tendon to bone.J Eng Mater Technol. 2011; : 133
- Graft fixation alternatives in anterior cruciate ligament reconstruction.Penn Orthop J. 2002; 15: 21-27
- A model of soft-tissue graft anterior cruciate ligament reconstruction in sheep.Arch Orthop Trauma Surg. 2005; 125: 238-248
- Anterior cruciate ligament repair with LARS (ligament advanced reinforcement system): A systematic review.Sports Med Arthrosc Rehabil Ther Technol. 2010; 2: 29-39
- Autograft and Leeds-Keio reconstructions of the ovine anterior cruciate ligament.Clin Orthop Relat Res. 1991; : 278-293
- Biological response to a new composite polymer augmentation device used for cruciate ligament reconstruction.J App Mat Res Part B. 2006; 76: 265-272
- Comparative animal study of three ligament prostheses for the replacement of the anterior cruciate and medial collateral ligament.Biomaterials. 1996; 17: 977-982
- Arthroscopic “second look” at the GORE-TEX ligament.Am J Sports Med. 1989; 17: 147-152
- Synthetic grafts for anterior cruciate ligament rupture: 19-Year outcome study.Knee. 2010; 17: 108-113
- Tibio-femoral joint contact forces in sheep.J Biomech. 2006; 39: 791-798
- Comparative anatomical measurements of osseous structures in the ovine and human.Knee. 2011; 18: 98-103
- Isometric reconstruction of the anterior cruciate ligament. Determination of the femoral and tibial tunnels.Acta Orthop Belg. 1996; 62: 166-177
- 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
Article info
Publication history
Accepted:
February 27,
2013
Received:
July 11,
2012
Footnotes
The authors report the following source of funding in relation to this article: Agence Nationale de la Recherche.
Identification
Copyright
© 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
