AN ANALYSIS OF ARTHROSCOPIC KNOT TECHNIQUES, IS THERE AN IDEAL KNOT?

Abstract

Introduction The aim of this study was to assess the efficacy of current arthroscopic knotting techniques with commonly used suture materials.

Methods A Hounsfield tensiometer with a 1000N load cell, strain rate of 25 mm/min, bar separation of 7.5 mm was used under standard temperature and pressure. Suture materials were those in common use; 2 Ethibond, 1 PDS and 1 Panacryl. The knotting techniques compared were the Tennessee slider, Tautline hitch, Duncan Loop, SMC knot and the Surgeon’s knot. Two surgeons tied each knot 10 times using a suture passer and standardised knot technique. Each knot was tested to failure on 10 sequential experiments. Suture material strength was tested alone, tested to failure using the different knots and after suture immersion in normal saline. The ultimate strength of the suture material and of the various knotting techniques were assessed. The mode of failure, slip or suture material fractured was also investigated.

Results The 2 Ethibond had superior strength compared to 1 PDS or 1 Panacryl. The Tautline hitch and Surgeon’s knot had a significantly lower slip rate, with superior internal security than the other knotting techniques (p < 0.002). The Tennessee slider, Duncan Loop and SMC knots slipped in more than 50% of experiments. No difference was observed after soaking in normal saline. The number of additional half hitches required for maximum knot holding was consistently three, confirming previous findings.

Conclusions The Tautline hitch is recommended with its superior internal security, tying characteristics and overall knot strength. Whichever arthroscopic knot is selected, the addition of three alternating half hitches for consistent security and reliability is strongly supported.