A Comparison between the Mechanical Behaviour of Steel Wires and Ultra High Molecular Weight Poly Ethylene Cables for Sternum Closure

Abstract

Sternum closure after open heart surgery is typically done with steel wires. Final approximation of sternal parts and connection is achieved by twisting the ends of the wire and bending the twisted assembly towards the sternum in order to minimize outward protrusion. Though this routine procedure is highly effective, some failures do occur, e.g. due to wire fracture. Fatigue fracture of the wires, e.g. due to coughing implies a failure risk. An alternative development is to make cables from gel spun Ultra High Molecular Weight Poly Ethylene (UHMWPE) fibres, such fibres are extremely strong, yet flexible, and if made as a very pure grade, they are highly bio compatible. The optimal connection technique will be different from that of steel. Connection will rather be with knotting than twisting. A new sternum closure and fixation technique has been developed for the sternum. Additionally, a testing technique was developed, for a connection of simulated sternum parts, using different materials according to their respective optimal connection method and subsequently testing the mechanical properties of the connection. Substantial differences were observed. The mechanical behaviour of twisted steel wire connection showed more scatter than the knotted UHMWPE cables and some initial slack was sometimes present in the twisted cables. The maximum attainable force in the steel wires was determined by “untwisting” due to the external load. The maximum force in the UHMWPE cables was determined by the knot strength, either slipping for small knots, or breaking of the cables at the knots for slip-improved knots. The maximum force on the knotted UHMWPE cables was substantially larger than the maximum force on the twisted steel wires. Fatigue tests were performed on both the steel solution and the UHMWPE cables solution. The performance was about similar, although the simulated sternum opening was smaller for the UHMWPE cables at higher load levels. Summarizing, the UHMWPE cables show two advantages namely higher maximum load and more reproducible mechanical behaviour due to less scatter in the mechanical behaviour. On the other hand, the connection by knotting UHMWPE cables is somewhat more elaborate than the simple twisting connection of steel wires.

Share and Cite:

R. Marissen, M. Nelis, M. Janssens, M. Meeks and J. Maessen, "A Comparison between the Mechanical Behaviour of Steel Wires and Ultra High Molecular Weight Poly Ethylene Cables for Sternum Closure," Materials Sciences and Applications, Vol. 2 No. 10, 2011, pp. 1367-1374. doi: 10.4236/msa.2011.210185.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] C. C. Shih, C. M. Shih, Y. Y. Su and S. J. Lin, “Potential Risk of Sternal Wires,” European Journal of Cardio-Tho- racic Surgery, Vol. 25, No. 5, 2004, pp. 812-818.
[2] C. M. Shih, Y. Y. Su, S. J. Lin and C. C. Shih, “Failure Analysis of Explanted Sternal Wires,” Biomaterials, Vol. 26, No. 14, 2005, pp. 2053-2059. doi:10.1016/j.biomaterials.2004.07.005
[3] K. Schulte, R. Marissen, K. H. Trautmann and H. No- wack, “A Contribution to the Evaluation of Sequence Effects under Variable Amplitude Loading by Applying Defined Predeformations,” AFMMS Conference, Freiburg, 20-24 June 1983, In: G. Sih, E. Sommer and W. Dahl, Eds., Application of Fracture Mechanics to Materials and Structures, 1984, pp. 777-785.
[4] L. van Rhijn, “A New Material for the Engineer’s Toolbox: Medical Grade UHMWPE Fibers Provide an Opportunity to Improve Device Performance and Patient Outcomes in MIS,” Bonezone, Winter 2009. http://medical.dyneema.com/downloadfile.php?file_name=Bonezone_0286082001267369707.pdf
[5] P. M. Montavon and S. Tepic, “Joint Surgery in Canine Hind Limb―Recent Contributions from the University of Zurich,” European Companion Animal Health, 2006. http://www.touchbriefings.com/pdf/2398/tepic.pdf
[6] P. Smith and P. J. Lemstra, “Ultrahigh Strength Polyethylene Filaments by Solution Spinning and Drawing,” Journal of Materials Science, Vol. 15, No. 2, 1980, pp. 505-514. doi:10.1007/BF02396802
[7] J. G. H. Bouwmeester, R. Marissen and O. K. Bergsma, “Carbon/Dyneema? Intralaminar Hybrids: New Strategy to Increase Impact Resistance or Decrease Mass of Carbon Fiber Composites,” ICAS2008 Conference Anchorage, Alaska, 14-19 September 2008, pp, 1-6.
[8] I. Yonezawa, Y. Arai, T. Tsuji, M. Takahashi and H. Kurosawa, “Atlantoaxial Transarticular Screw Fixation and Posterior Fusion Using Ultra-High-Molecular-Weight Polyethylene Cable,” Journal of Spinal Disorders & Tech- niques, Vol. 18, No. 5, 2005, pp. 392-395. doi:10.1097/01.bsd.0000167127.16576.02
[9] P. G. Rothaug, R. C. Boston, D. W. Richardson and D. M. Nunamaker, “A Comparison of Ultra-High-Molecular Weight Polyethylene Cable and Stainless Steel Wire Using Two Fixation Techniques for Repair of Equine Sesamoid Fractures: An in Vitro Biomechanical Study,” Veterinary Surgery, Vol. 31, No. 5, 2002, pp. 445-454. doi:10.1053/jvet.2002.34668
[10] J. E. Losanoff, A. D. Collier, C. C. Wagner-Mann, B. W. Richman, H. Huff, F. H. Hsieh, A. Diaz-Arias and J. W. Jones, “Biomechanical Comparison of Median Sternotomy Closures,” The Annuals of Thoracic Surgery, Vol. 77, 2004, pp. 203-209.
[11] A. R. Casha, L. Yang, P. H. Kay, M. Saleh and G. J. Cooper, “A Biomechanical Study of Median Sternotomy Closure Techniques,” European Journal of Cardio-Tho- racic Surgery, Vol. 15, No. 3, 1999, pp. 365-369. doi:10.1016/S1010-7940(99)00014-7

Copyright © 2024 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.