UZH-Logo

Maintenance Infos

Surgical knot tightening: how much pull is necessary?


Neuhofer, Stefan; Wieser, Karl; Lajtai, Georg; Müller, Daniel; Gerber, Christian; Meyer, Dominik C (2014). Surgical knot tightening: how much pull is necessary? Knee Surgery, Sports Traumatology, Arthroscopy, 22(11):2849-2855.

Abstract

PURPOSE: High-strength sutures allow tightening of a suture knot beyond the strength of the surgeon, possibly inflicting skin damage through the gloves. This study was undertaken to evaluate whether such effort is useful and how much tensioning on a surgical knot is necessary. METHODS: Three different suture materials were tested: No. 2 Vicryl™, FibreWire™, and PDS™. First, the force spontaneously applied on sutures during experimental knot tightening ("tying load") was measured in fifteen experienced surgeons. Second, with each suture material, surgical square knots were tied with increasing, standardized loads (range 0.5-50 N) using a custom-made apparatus. Thereby, knot seating after tying was evaluated, and by loading the knots to failure, evaluation for failure mode and failure load was performed. RESULTS: FibreWire™ 5-throw square knots always failed by complete slipping of all knots (resolving), independent on the tying load. A nonlinear decrease of knot slippage and increased failure load were seen with increasing tying loads for all sutures. Major differences were seen between 0.5 and 10 N for FibreWire™ (slippage: 25 mm) and PDS™ (99.6 mm), whereas Vicryl™ showed major differences (22.7 mm) between 0.5 and 2 N. Increasing the tying load from 10 to 50 N decreased the mean knot slippage from 12 (FibreWire™, ±2.6 SD), 9 (PDS™, ±1.8 SD) and 8 (Vicryl™, ±1.3 SD) mm to 6 (±2.9 SD), 3 (±1.5 SD) and 4 mm (±0.9 SD), respectively. CONCLUSION: Slippage and self-seating of the knots under load is unavoidable even with highest tying loads. Relatively minor but possibly important differences can be seen for tying loads exceeding 2 N (Vicryl™) and 10 N (PDS™ and FibreWire™) for failure load and knot slippage. But also with a tying load of 50 N, a minimal slippage of approximately 3 mm seems unavoidable for all suture types. However, it is important to state that intense tightening does not prevent knot resolution and is only necessary in clinical situations that demand very tight sutures. Numbers and proper appliance of throws are more relevant than tying strength to reach the maximum failure load.

Abstract

PURPOSE: High-strength sutures allow tightening of a suture knot beyond the strength of the surgeon, possibly inflicting skin damage through the gloves. This study was undertaken to evaluate whether such effort is useful and how much tensioning on a surgical knot is necessary. METHODS: Three different suture materials were tested: No. 2 Vicryl™, FibreWire™, and PDS™. First, the force spontaneously applied on sutures during experimental knot tightening ("tying load") was measured in fifteen experienced surgeons. Second, with each suture material, surgical square knots were tied with increasing, standardized loads (range 0.5-50 N) using a custom-made apparatus. Thereby, knot seating after tying was evaluated, and by loading the knots to failure, evaluation for failure mode and failure load was performed. RESULTS: FibreWire™ 5-throw square knots always failed by complete slipping of all knots (resolving), independent on the tying load. A nonlinear decrease of knot slippage and increased failure load were seen with increasing tying loads for all sutures. Major differences were seen between 0.5 and 10 N for FibreWire™ (slippage: 25 mm) and PDS™ (99.6 mm), whereas Vicryl™ showed major differences (22.7 mm) between 0.5 and 2 N. Increasing the tying load from 10 to 50 N decreased the mean knot slippage from 12 (FibreWire™, ±2.6 SD), 9 (PDS™, ±1.8 SD) and 8 (Vicryl™, ±1.3 SD) mm to 6 (±2.9 SD), 3 (±1.5 SD) and 4 mm (±0.9 SD), respectively. CONCLUSION: Slippage and self-seating of the knots under load is unavoidable even with highest tying loads. Relatively minor but possibly important differences can be seen for tying loads exceeding 2 N (Vicryl™) and 10 N (PDS™ and FibreWire™) for failure load and knot slippage. But also with a tying load of 50 N, a minimal slippage of approximately 3 mm seems unavoidable for all suture types. However, it is important to state that intense tightening does not prevent knot resolution and is only necessary in clinical situations that demand very tight sutures. Numbers and proper appliance of throws are more relevant than tying strength to reach the maximum failure load.

Citations

2 citations in Web of Science®
2 citations in Scopus®
Google Scholar™

Altmetrics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Balgrist University Hospital, Swiss Spinal Cord Injury Center
Dewey Decimal Classification:610 Medicine & health
Language:English
Date:November 2014
Deposited On:03 Feb 2014 15:50
Last Modified:05 Apr 2016 17:27
Publisher:Springer
ISSN:0942-2056
Publisher DOI:https://doi.org/10.1007/s00167-013-2452-9
PubMed ID:23494026

Download

Full text not available from this repository.
View at publisher

TrendTerms

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.
You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.

Author Collaborations