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Embossing of a screw thread and TCP granules enhances the fixation strength of compressed ACL grafts with interference screws

  • Knee
  • Published:
Knee Surgery, Sports Traumatology, Arthroscopy Aims and scope

Abstract

Purpose

Fixation of soft tissue grafts with interference screws relies on the friction of the graft between the screw and the bone tunnel. The goal of this study was to precondition such grafts by mechanical compression in order to reduce anticipated and undesired viscoelastic adaptation of the graft to screw pressure. Further, the otherwise slippery graft surface was modified with impressed tricalcium phosphate granules (TCP) to improve friction and mechanical hold.

Methods

Fresh flexor digitorum tendons from young bovines were used to create bundles with a diameter of 8–9 mm and were divided into 10 groups to compare the pullout strength and bone damage in a variety of construct scenarios. Specifically, the effects of graft precompression to reduce preimplantation graft diameter were investigated. Further the effects of impressing TCP granules and/or a screw thread into the tendon surface during the compression process were studied.

Results

In sawbone tests, radial graft compression allowed for a smaller bone tunnel (7 mm), but resulted in a significantly lower pullout strength of 174 N (95% CI: 97, 250), compared with controls [315 N (204, 426)]. In contrast, TCP coated [402 N (243, 561)], screw embossed grafts [458 N (302, 614)], and the combination of TCP and embossing [409 N (274, 543)] achieved higher pullout strengths when compared to the standard technique. In porcine bone, untreated grafts using an 8 mm screw pulled out at 694 ± 93 N, significantly higher loads were required to pullout compressed grafts with or without TCP coating (870 ± 74 and 878 ± 131 N), yet fixed with a 7 mm screw.

Conclusion

Modification of the tendon graft surface has a large influence on the biomechanical performance of interference screw fixation and results in less bone damage inflicted during insertion to a smaller tunnel diameter, while simultaneously achieving superior pullout strength.

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References

  1. Becker R, Voigt D, Starke C et al (2001) Biomechanical properties of quadruple tendon and patellar tendon femoral fixation techniques. Knee Surg Sports Traumatol Arthrosc 9:337–342

    Article  PubMed  CAS  Google Scholar 

  2. Donahue TL, Gregersen C, Hull ML et al (2001) Comparison of viscoelastic, structural, and material properties of double-looped anterior cruciate ligament grafts made from bovine digital extensor and human hamstring tendons. J Biomech Eng 123:162–169

    Article  PubMed  CAS  Google Scholar 

  3. Drogset JO, Strand T, Uppheim G et al (2010) Autologous patellar tendon and quadrupled hamstring grafts in anterior cruciate ligament reconstruction: a prospective randomized multicenter review of different fixation methods. Knee Surg Sports Traumatol Arthrosc 18:1085–1093

    Article  PubMed  Google Scholar 

  4. Drogset JO, Straume LG, Bjorkmo I et al (2011) A prospective randomized study of acl-reconstructions using bone-patellar tendon-bone grafts fixed with bioabsorbable or metal interference screws. Knee Surg Sports Traumatol Arthrosc 19:753–759

    Article  PubMed  Google Scholar 

  5. Fabbriciani C, Mulas PD, Ziranu F et al (2005) Mechanical analysis of fixation methods for anterior cruciate ligament reconstruction with hamstring tendon graft. An experimental study in sheep knees. Knee 12:135–138

    Article  PubMed  Google Scholar 

  6. Giurea M, Zorilla P, Amis AA et al (1999) Comparative pull-out and cyclic-loading strength tests of anchorage of hamstring tendon grafts in anterior cruciate ligament reconstruction. Am J Sports Med 27:621–625

    PubMed  CAS  Google Scholar 

  7. Halewood C, Hirschmann MT, Newman S et al (2011) The fixation strength of a novel acl soft-tissue graft fixation device compared with conventional interference screws: a biomechanical study in vitro. Knee Surg Sports Traumatol Arthrosc 19:559–567

    Article  PubMed  Google Scholar 

  8. Jarvinen TL, Nurmi JT, Sievanen H (2004) Bone density and insertion torque as predictors of anterior cruciate ligament graft fixation strength. Am J Sports Med 32:1421–1429

    Article  PubMed  Google Scholar 

  9. Micucci CJ, Frank DA, Kompel J et al (2010) The effect of interference screw diameter on fixation of soft-tissue grafts in anterior cruciate ligament reconstruction. Arthroscopy 26:1105–1110

    Article  PubMed  Google Scholar 

  10. Nebelung W, Becker R, Urbach D et al (2003) Histological findings of tendon-bone healing following anterior cruciate ligament reconstruction with hamstring grafts. Arch Orthop Trauma Surg 123:158–163

    PubMed  CAS  Google Scholar 

  11. Nyland J, Kocabey Y, Caborn DN (2004) Insertion torque pullout strength relationship of soft tissue tendon graft tibia tunnel fixation with a bioabsorbable interference screw. Arthroscopy 20:379–384

    Article  PubMed  Google Scholar 

  12. Colvin A, Sharma C, Parides M et al (2011) What is the best femoral fixation of hamstring autografts in anterior cruciate ligament reconstruction?: a meta-analysis. Clin Orthop Relat Res 469:1075–1081

    Google Scholar 

  13. Reigstad O, Franke-Stenport V, Johansson CB et al (2007) Improved bone ingrowth and fixation with a thin calcium phosphate coating intended for complete resorption. J Biomed Mater Res B Appl Biomater 83:9–15

    PubMed  CAS  Google Scholar 

  14. Roy S, Fernhout M, Stanley R et al (2010) Tibial interference screw fixation in anterior cruciate ligament reconstruction with and without autograft bone augmentation. Arthroscopy 26:949–956

    Article  PubMed  Google Scholar 

  15. Shen PH, Lien SB, Shen HC et al (2009) Comparison of different sizes of bioabsorbable interference screws for anterior cruciate ligament reconstruction using bioabsorbable bead augmentation in a porcine model. Arthroscopy 25:1101–1107

    Article  PubMed  Google Scholar 

  16. Sim JA, Kwak JH, Yang SH et al (2009) Comparative biomechanical study of the ligament plate and other fixation devices in acl reconstruction. Int Orthop 33:1269–1274

    Article  PubMed  Google Scholar 

  17. Weimann A, Rodieck M, Zantop T et al (2005) Primary stability of hamstring graft fixation with biodegradable suspension versus interference screws. Arthroscopy 21:266–274

    Article  PubMed  Google Scholar 

  18. Wen CY, Qin L, Lee KM et al (2009) The use of brushite calcium phosphate cement for enhancement of bone-tendon integration in an anterior cruciate ligament reconstruction rabbit model. J Biomed Mater Res B Appl Biomater 89B:466–474

    Article  CAS  Google Scholar 

  19. Zantop T, Kubo S, Petersen W et al (2007) Current techniques in anatomic anterior cruciate ligament reconstruction. Arthroscopy 23:938–947

    Article  PubMed  Google Scholar 

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Conflict of interest

The following authors have claimed intellectual property ownership related to the manuscript content: Mazda Farshad, Jess G. Snedeker, Dominik C. Meyer, but have no other conflicts of interest to disclose.

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Authors and Affiliations

  1. Balgrist University Hospital, University of Zürich, Forchstrasse 340, 8008, Zurich, Switzerland

    Mazda Farshad, Robert A. Weinert-Aplin, Michael Stalder, Peter P. Koch, Jess G. Snedeker & Dominik C. Meyer

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  1. Mazda Farshad
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  2. Robert A. Weinert-Aplin
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  3. Michael Stalder
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  4. Peter P. Koch
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  5. Jess G. Snedeker
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  6. Dominik C. Meyer
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Correspondence to Mazda Farshad.

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Farshad, M., Weinert-Aplin, R.A., Stalder, M. et al. Embossing of a screw thread and TCP granules enhances the fixation strength of compressed ACL grafts with interference screws. Knee Surg Sports Traumatol Arthrosc 20, 268–274 (2012). https://doi.org/10.1007/s00167-011-1623-9

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  • DOI: https://doi.org/10.1007/s00167-011-1623-9

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