Dominik C Meyer1, Elias Bachmann1, Alexandre Lädermann2, Georg Lajtai3, Thorsten Jentzsch4. 1. Department of Orthopedics, Balgrist University Hospital, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland. 2. Division of Orthopaedics and Trauma Surgery, La Tour Hospital, Meyrin, Switzerland; Faculty of Medicine, University of Geneva, Geneva, Switzerland; Division of Orthopaedics and Trauma Surgery, Department of Surgery, Geneva University Hospitals, Geneva, Switzerland. 3. Orthopedic Department, Private Hospital Maria Hilf, Klagenfurt, Karnten, Austria. 4. Department of Orthopedics, Balgrist University Hospital, University of Zurich, Forchstrasse 340, 8008 Zurich, Switzerland. Electronic address: thorsten.jentzsch@balgrist.ch.
Abstract
PURPOSE: Surgical knots are particularly challenged by high-strength suture material. It was hypothesized that sutures in a double-stranded looped configuration present mechanical advantages. METHODS: This in vitro biomechanical study repeatedly tested 12 different knots with a static distraction material testing machine with a constant tensile speed. The cow hitch, its altered version, and conventional half hitches were also tested on bovine tendon. Suture material was braided polyblend non-bioresorbable polyester. Primary outcome was knot security (stiffness) at clinical failure (≥3mm displacement). Secondary outcomes were knot size and loop security. RESULTS: Double-stranded looped knots were up to three times stronger than one and a half- and single-stranded knots. The cow hitch was stiffest (mean 185 [95% CI 172-197]Newton per millimeter [N/mm]) (p<0.001), followed by the Nice knot (169 [154-183]N/mm). It was stiffer than half hitches (65 [53-78]N/mm). These findings remained in tendons (82 [77-86] and 40 [32-49]N/mm, p<0.001). The cow hitch (7.6mm3) and Nice knot (6.1mm3) were smaller than half hitches (9.5mm3). Loop security did not differ between the cow hitch and Nice knot, but was higher in the cow hitch than half hitch (158 [120-196]N and 85 [57-113]N, p<0.001). CONCLUSIONS: Double-stranded knot configurations with a loop on one side are mechanically stronger and stiffer, less bulky, and preserve applied tension during tying better than conventional knots. The best performing and technically most simple knots best suited to exploit enormous mechanical capabilities of modern high-strength suture material are the cow hitch and Nice knot. LEVEL OF EVIDENCE: Not applicable due to the biomechanical nature of the study.
PURPOSE: Surgical knots are particularly challenged by high-strength suture material. It was hypothesized that sutures in a double-stranded looped configuration present mechanical advantages. METHODS: This in vitro biomechanical study repeatedly tested 12 different knots with a static distraction material testing machine with a constant tensile speed. The cowhitch, its altered version, and conventional half hitches were also tested on bovine tendon. Suture material was braided polyblend non-bioresorbable polyester. Primary outcome was knot security (stiffness) at clinical failure (≥3mm displacement). Secondary outcomes were knot size and loop security. RESULTS: Double-stranded looped knots were up to three times stronger than one and a half- and single-stranded knots. The cowhitch was stiffest (mean 185 [95% CI 172-197]Newton per millimeter [N/mm]) (p<0.001), followed by the Nice knot (169 [154-183]N/mm). It was stiffer than half hitches (65 [53-78]N/mm). These findings remained in tendons (82 [77-86] and 40 [32-49]N/mm, p<0.001). The cowhitch (7.6mm3) and Nice knot (6.1mm3) were smaller than half hitches (9.5mm3). Loop security did not differ between the cowhitch and Nice knot, but was higher in the cowhitch than half hitch (158 [120-196]N and 85 [57-113]N, p<0.001). CONCLUSIONS: Double-stranded knot configurations with a loop on one side are mechanically stronger and stiffer, less bulky, and preserve applied tension during tying better than conventional knots. The best performing and technically most simple knots best suited to exploit enormous mechanical capabilities of modern high-strength suture material are the cowhitch and Nice knot. LEVEL OF EVIDENCE: Not applicable due to the biomechanical nature of the study.
Authors: Zoe Ashbridge; Stephen D P Fielden; David A Leigh; Lucian Pirvu; Fredrik Schaufelberger; Liang Zhang Journal: Chem Soc Rev Date: 2022-09-20 Impact factor: 60.615
Authors: Florian Grubhofer; Elias Bachmann; Christian Gerber; Karl Wieser; Lukas Ernstbrunner; Jon Jp Warner; Samy Bouaicha Journal: JSES Int Date: 2020-12-14