A study on elongation and knot slacking of various sutures.

The tension holding capacity of suture materials was measured by in vitro and in vivo experiments. Silk and expanded polytetrafluoroethylene sutures showed large elongation and significant knot slacking after tight tying. Although ultrahigh molecular-weight polyethylene suture had excellent creep resistance, it showed a relatively low tension holding capacity because of substantial knot slacking. On the other hand, polyester and high-strength poly(vinyl alcohol) sutures showed an excellent in vivo tension holding capacity, along with low elongation and insignificant knot slacking. Clinical performance of these sutures was briefly discussed from the mechanical point of view.