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veterinary
farriery
2005
Expert Opinion

An in vitro biomechanical comparison of the breaking strength and stiffness of polydioxanone (sizes 2, 7) and polyglactin 910 (sizes 3, 6) in the equine linea alba.

Authors: Fierheller Erin E, Wilson David G

Journal: Veterinary surgery : VS

Summary

Abdominal wall closure remains a critical consideration in equine surgical practice, yet comparative data on suture performance in linea alba repair have been limited. Fierheller and Wilson tested four suture constructs—polydioxanone sizes 2 and 7 (PD) and polyglactin 910 sizes 3 and 6 (PG)—using fresh linea alba tissue harvested from 12 horses and subjected to single-cycle tensile loading at 100 mm/min until failure. Size 7 polydioxanone demonstrated superior breaking strength at 316.8 N, substantially outperforming size 2 polydioxanone (193.0 N) and both polyglactin materials; however, size 6 polyglactin exhibited the highest stiffness (14 N/mm), which may influence load distribution differently during healing. Critically, suture material itself consistently failed before linea alba tissue in 94 of 96 specimens, with 90.4% of failures occurring adjacent to the knot, indicating that knot security and suture calibre are the limiting factors rather than tissue integrity. For practitioners prioritising immediate post-operative strength during the critical early healing phase, size 7 polydioxanone offers the optimal balance of breaking strength and proven in vivo longevity, though the superior stiffness of size 6 polyglactin warrants consideration where load distribution properties may be advantageous.

Read the full abstract on PubMed

Practical Takeaways

  • Use size 7 polydioxanone for equine linea alba closure when maximum initial strength is needed, as it provides the best breaking strength profile in this tissue
  • Avoid undersized sutures (size 2) for abdominal wall closure in horses, as they have significantly lower failure strength (193 N vs 316.8 N) with no biomechanical advantage
  • Pay particular attention to knot placement and technique, as 90% of failures occur at the knot—proper knot security is the critical variable in closure longevity

Key Findings

  • Size 7 polydioxanone had the highest breaking strength at 316.8 N, significantly outperforming smaller suture sizes across both material types
  • Larger suture materials demonstrated both higher breaking strength and greater stiffness, with size 6 polyglactin 910 achieving 14 N/mm stiffness
  • Suture material failed in 94 of 96 specimens rather than linea alba tissue, indicating suture selection is the critical failure variable
  • 90.4% of suture loop failures occurred adjacent to the knot, identifying a consistent weak point in closure techniques

Conditions Studied

linea alba repairabdominal wall closurefascial integrity