A biomechanical comparison of multistrand flexor tendon repairs using an in situ testing model

J Hand Surg Am. 2000 May;25(3):499-506. doi: 10.1053/jhsu.2000.6927.


An in situ testing model was used to evaluate the performance of zone II flexor tendon repairs and to compare the biomechanical properties of 4-strand repairs with 2- and 6-strand repairs. Fifty digits from human cadaveric hands were mounted in a custom apparatus for in situ tensile testing. Intratendinous metallic markers were placed so that gap formation could be determined by fluoroscopy during tensile testing. Three 4-strand repairs (the 4-strand Kessler, the cruciate, and a locked modification of the cruciate repair) were compared with the 2-strand Kessler and the 6-strand Savage repairs. Ultimate tensile strength, load at 2-, 3-, and 4-mm gap formation, and work of flexion were determined. Work of flexion, while increased for the multistrand repairs, did not show a statistically significant correlation with the number of strands crossing the repair site. The tensile strength of the 6-strand repair was significantly greater than each of the 2- or 4-strand repairs. The tensile strength of all 4-strand repairs was significantly greater than the 2-strand repair. The 6-strand repair and the 2 cruciate repairs demonstrated a statistically increased resistance to gap formation compared with the 2-strand Kessler repair, but notably there was no statistically significant difference in gap resistance between the 2and 4-strand Kessler repairs. This in situ tensiletesting protocol demonstrated that 4- and 6-strand repairs have adequate initial strength to withstand the projected forces of early active motion protocols. Three of the 4 multistrand repairs demonstrated improved gap resistance compared with the 2-strand repair. The presence of the second suture in the Kessler configuration significantly increases its strength but not its gap resistance.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Biomechanical Phenomena
  • Cadaver
  • Gap Junctions / physiology*
  • Humans
  • Metacarpus / physiology
  • Models, Biological
  • Probability
  • Stress, Mechanical
  • Suture Techniques
  • Sutures*
  • Tendons / surgery*
  • Tensile Strength
  • Wound Healing / physiology