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Bushong EE, Janis JE. Knot Security 101: A Comprehensive Practical Review to Optimal Knot Configuration, Pulling Direction, Throw Count, and Tail Length. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2024; 12:e6047. [PMID: 39139841 PMCID: PMC11319322 DOI: 10.1097/gox.0000000000006047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 06/05/2024] [Indexed: 08/15/2024]
Abstract
Background Knots are the weakest structural point in a suture line and inevitably weaken almost all suture materials. This practical review critically evaluates the factors, such as suture material properties, gauge, configuration, throw count, and tail length, that affect knot security. Methods A PubMed search between the years 1934 and 2023 identified relevant studies that addressed factors relating to knot security. Studies that investigated knots and sutures solely used in laparoscopic and arthroscopic surgery were excluded. Knot configurations assessed were the Aberdeen, sliding, square, and surgeon's. Results Eighty-six articles were included in this review article and demonstrated that knot security varies greatly between suture materials and gauge. Knot security also varies by configuration, throw count, conditions, tail length, and stitch type. Throw count differs by knot configuration, with the Aberdeen knot being most secure with three throws and one to two turns compared with three to five throws for surgeon's and square knots. The optimal tail length was 3 mm. Conclusions This practical review demonstrates that there are significant differences in knot security based on a variety of factors. It is challenging to propose an ideal knot because most studies did not evaluate knot security using a broad variety of suture materials, gauges, and throws for each of the most common knots. Although this review article demonstrated several applicable findings, additional robust studies are needed to simplify proposals.
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Affiliation(s)
- Elizabeth E. Bushong
- From the Michigan State University College of Human Medicine, Grand Rapids, Mich
| | - Jeffrey E. Janis
- Department of Plastic and Reconstructive Surgery, The Ohio State University, Columbus, Ohio
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Barnes HK, Munsterman AS, Gillen AM, Caston SS, Tatarniuk DM, Kersh K, Swor T, Hanson RR. Evaluation of the in vitro performance of the double forwarder knot, compared to square and surgeon's knots using large gauge suture. Vet Surg 2024; 53:376-383. [PMID: 38151296 DOI: 10.1111/vsu.14058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 11/02/2023] [Accepted: 11/24/2023] [Indexed: 12/29/2023]
Abstract
OBJECTIVE The aim of the study was to evaluate the strength and size of the double forwarder (DF) knot in 2 and 3 USP polyglactin 910 when used to form a ligature and to compare the knot holding capacity (KHC), size and weight of the DF knot to surgeon's (SU) and square (SQ) knots with varying numbers of throws. STUDY DESIGN Laboratory study. STUDY POPULATION Knotted suture. METHODS Knots were tied using 2 and 3 USP polyglactin 910 and tested on a universal testing machine under linear tension. Mode of failure and (KHC) were recorded. Knot volume and weight were determined by digital micrometer and balance. KHC, size, and weight between knot type, number of throws, and suture type and size were compared using ANOVA testing, with p < .05 as significant. RESULTS In both suture types, DF knots had a higher KHC than SQ/SU knots (p < .004), with the exception of SU knots with 6-8 throws in 3 USP polyglactin 910 (p > .42). All DF knots failed by suture breakage at the knot, as did all SQ/SU knots with >6 throws. DF knots in 2 and 3 USP polyglactin 910 were larger and heavier than SQ and SU knots when the same number of throws was applied (p < .003). CONCLUSION Self-locking DF knots provided increased strength compared to SU/SQ in large gauge suture but only when fewer than six throws are applied to SU/SQ knots. CLINICAL RELEVANCE The new DF knot could be an alternative for a secure ligature.
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Affiliation(s)
- Harriet K Barnes
- Philip Leverhulme Equine Hopsital, University of Liverpool, Neston, UK
| | - Amelia S Munsterman
- Veterinary Medical Center, Michigan State University, East Lansing, Michigan, USA
| | - Alex M Gillen
- Philip Leverhulme Equine Hopsital, University of Liverpool, Neston, UK
| | | | | | - Kevin Kersh
- Lloyd Large Animal Hospital, Iowa State University, Ames, Iowa, USA
| | - Tamara Swor
- Lloyd Large Animal Hospital, Iowa State University, Ames, Iowa, USA
| | - R Reid Hanson
- JT Vaughan Large Animal Teaching Hospital, Auburn University, Auburn, Alabama, USA
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Tobias K, Mulon PY, Daniels A, Sun X. Does quality of novice hand-tied square knots improve with repetition during a single training session? PeerJ 2022; 10:e14106. [PMID: 36187746 PMCID: PMC9521345 DOI: 10.7717/peerj.14106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 09/01/2022] [Indexed: 01/21/2023] Open
Abstract
Background Knot tying is a key surgical skill for novices, and repetition over several training sessions improves knot tying. This study examined the effects of repetition within a single training session on quality of knotted loops and compared results of novice trainees and experienced surgeons. Methods Using 0.55 mm nylon monofilament fishing line, novices and surgeons each hand-tied 20 knotted loops, using a 2=1=1=1 configuration (surgeon's throw and three square throws). Loops were mechanically tested with a single load to failure. Results All loops tolerated five newtons (N) preload. More than 70% of novice and surgeon knots failed by slipping or untying, and 8.8% of novice knots and 2.5% of surgeon's knots were considered dangerous. Surgeons' loops had less extension at preload, indicating better loop security. However, during single test to failure, there was no difference in mean extension or maximum load between surgeons and novices. There was no significant difference in results of mechanical testing or modes of failure for the first and last ten knotted loops, or the first, second, third, and fourth sets of knotted loops. Discussion With appropriate training, novices can construct knots as strong and secure as experienced surgeons. A large percentage of knotted loops are insecure under testing conditions; extra throws may be required when using large diameter monofilament nylon. Novices may require extra training in maintenance of loop security when constructing square knots. Tying more than five or 10 knotted loops within a single training session does not provide added benefits for novices.
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Affiliation(s)
- Karen Tobias
- Small Animal Clinical Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States of America
| | - Pierre-Yves Mulon
- Department of Large Animal Clinical Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States of America
| | - Alec Daniels
- Small Animal Clinical Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States of America
| | - Xiaocun Sun
- Office of Information Technology, University of Tennessee Knoxville, Knoxville, TN, United States of America
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Gillen A, Munsterman A, Barrett E, Caston S, Kersh K, Tatarniuk D, Swor T, Hanson RR. In vitro evaluation of the modified forwarder knot used to end a continuous suture pattern in large-gauge suture. Vet Surg 2020; 49:1555-1562. [PMID: 32959894 DOI: 10.1111/vsu.13519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/12/2020] [Accepted: 08/31/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the strength and size of forwarder end (FE) knots modified to end continuous suture lines compared with Aberdeen (AB), square (SQ), and surgeon's (SU) knots. STUDY DESIGN In vitro mechanical study. STUDY POPULATION Knotted suture. METHODS Knots were tied with 2 USP (United States Pharmacopeia) polydioxanone, 2 USP, and 3 USP polyglactin 910 and tested on a universal testing machine under linear tension. Mode of failure and knot holding capacity (KHC) were recorded, and relative knot security (RKS) was calculated. Knot volume and weight were determined by digital micrometer and balance. Knot holding capacity, RKS, size, and weight between knot type, number of throws, and suture type and size were compared by using analysis of variance testing, with P < .05 considered significant. RESULTS In all suture types and number of throws, FE knot KHC/RKS was 28% to 66.99% (1.2-1.6 fold) stronger compared with SQ/SU knots (P < .001). For 2 USP polydioxanone, FE knots had 10% (1.1 fold) higher KHC/RKS compared with AB knots (P < .042). However, in 2 and 3 USP polyglactin 910, FE knot KHC/RKS values were not different from those of AB knots (P > .080). Forwarder end/AB knots failed by suture breakage at the knot, whereas some SQ/SU knots unraveled. Forwarder end knots in 2 and 3 USP polyglactin 910 were 21.1% to 44.4% (1.2-1.4 fold) smaller compared with SQ/SU knots (P < .028). Forwarder end knots in 2 and 3 USP polyglactin 910 were 40% to 99% (1.4-2.0 fold) larger compared with AB knots (P < .001). CONCLUSION Forwarder end knots provided increased KHC/RKS compared with SQ/SU knots. CLINICAL RELEVANCE Forwarder end knots should be considered for closures when suture is placed under tension.
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Affiliation(s)
- Alex Gillen
- Philip Leverhulme Equine Hospital, Department of Veterinary Science, University of Liverpool, Cheshire, United Kingdom
| | - Amelia Munsterman
- Morrie Waud Large Animal Hospital, Department of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Erin Barrett
- Lloyd Large Animal Hospital, Department of Veterinary Medicine, Iowa State University, Iowa, USA
| | - Stephanie Caston
- Lloyd Large Animal Hospital, Department of Veterinary Medicine, Iowa State University, Iowa, USA
| | - Kevin Kersh
- Lloyd Large Animal Hospital, Department of Veterinary Medicine, Iowa State University, Iowa, USA
| | - Dane Tatarniuk
- Lloyd Large Animal Hospital, Department of Veterinary Medicine, Iowa State University, Iowa, USA
| | - Tamara Swor
- Lloyd Large Animal Hospital, Department of Veterinary Medicine, Iowa State University, Iowa, USA
| | - R Reid Hanson
- J T Vaughan Large Animal Hospital, Department of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
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Weatherall KM, Boone LH, Caldwell FJ, Cole RC, Cattley RC, Lascola KM, Clark-Price SC, Farag R, Perkins E, Hanson RR. Tensile strength and early healing of self-locking and surgeon's knots. Vet Surg 2020; 49:1580-1589. [PMID: 32780444 DOI: 10.1111/vsu.13497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 06/07/2020] [Accepted: 07/11/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To compare the biomechanical properties and healing of ventral midline celiotomies (VMC) closed with a self-locking knot combination and forwarder start and Aberdeen end (F-A) vs a traditional knot combination and surgeon's start and end (S-S). STUDY DESIGN In vivo, experimental. ANIMALS Twenty-one horses. METHODS Fourteen horses underwent VMC, which was closed with either an F-A (n = 7) or an S-S (n = 7) knot combination. Incisions were subjectively graded by masked evaluators for dehiscence, edema, and drainage. Biomechanical testing was performed on three abdominal segments, and histology was performed on one segment from each animal after humane euthanasia 10 days post-VMC. The abdominal wall of control horses (n = 7, no celiotomy) was collected for biomechanical testing. RESULTS Forwarder start and Aberdeen end and S-S horses had less tensile strength compared with control horses (P ≤ .001). No differences were detected between treatment groups for any variable evaluated, including tensile strength (P = .975), location of failure (P = .240), and histologic healing at the knot (P = .600). CONCLUSION Closure of VMC with self-locking knots resulted in biomechanical and healing features similar to those with a traditional closure technique, with neither restoring the tensile strength of the linea alba. CLINICAL SIGNIFICANCE Results of this study provide evidence to support a clinical trial to evaluate long-term performance of the F-A self-locking knot closure in horses.
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Affiliation(s)
- Kathleen M Weatherall
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
| | - Lindsey H Boone
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
| | - Fred J Caldwell
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
| | - Robert C Cole
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
| | - Russell C Cattley
- Department of Pathobiology, Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
| | - Kara M Lascola
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
| | - Stuart C Clark-Price
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
| | - Ramsis Farag
- Center for Polymer and Advanced Composites, Auburn University Samuel Ginn College of Engineering, Auburn, Alabama, USA.,Department of Textile Engineering, Mansoura University, Mansoura, Egypt
| | - Edmon Perkins
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - R Reid Hanson
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
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Upchurch DA, Wang Y, Chen S, Roccabianca S, Roush JK. Assessment of time to completion, number of errors, and knot-holding capacity of square knots and Aberdeen knots tied by veterinary students and student perceptions of knot security and knot-tying difficulty. J Am Vet Med Assoc 2020; 256:230-238. [PMID: 31910084 DOI: 10.2460/javma.256.2.230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To assess the time to completion, number of errors, and knot-holding capacity (KHC) for starting and ending square knots (SSKs and ESKs) of a continuous pattern and Aberdeen knots tied by veterinary students and to investigate student perceptions of knot security and knot-tying difficulty for the 3 knot types. SAMPLE 16 second-year veterinary students. PROCEDURES Students created 3 (4-throw) SSKs, 3 (5-throw) ESKs, and 3 (3 + 1 configuration) Aberdeen knots with 2-0 polydioxanone on a custom test apparatus. Time to complete each knot, the number of errors in each knot, and student ratings of knot-tying difficulty and confidence in knot security were recorded. Each knot was tested to failure on a uniaxial tensiometer to determine KHC and mode of failure. Variables of interest were compared by repeated-measures ANOVA or the Friedman test with post hoc pairwise comparisons. RESULTS Mean knot completion time for Aberdeen knots was significantly less than mean completion time for SSKs or ESKs. Mean KHC was significantly lower for ESKs than for SSKs; KHC for Aberdeen knots was not compared with these values because of methodological differences. Median error rate was higher for ESKs than for other knot types. Mean difficulty rating for Aberdeen knots was lower than that for ESKs. Most tested knots failed by breakage at the knot. CONCLUSIONS AND CLINICAL RELEVANCE Aberdeen knots appeared to be easy for veterinary students to learn and were completed more rapidly and with fewer errors than ESKs. Including this type of knot in surgical skills curriculum for novices may be beneficial.
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McGlinchey L, Boone LH, Munsterman AS, Coleridge MOD, Rosanowski SM, Farag R, Hanson RR. In vitro evaluation of the knot-holding capacity and security, weight, and volume of forwarder knots tied with size-3 polyglactin 910 suture exposed to air, balanced electrolyte solution, or equine abdominal fat. Am J Vet Res 2019; 80:709-716. [PMID: 31246130 DOI: 10.2460/ajvr.80.7.709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the effect of exposure to a balanced electrolyte solution (BES), or equine abdominal fat on the knot-holding capacity (KHC), relative knot security (RKS), weight, and volume of forwarder knots versus surgeon's knots. SAMPLE 315 knots tied and tested in vitro. PROCEDURES United States Pharmacopeia size-3 polyglactin 910 suture exposed to air (dry [control]), equine abdominal fat (fat-exposed), or BES (BES-exposed) was used to tie forwarder knots with 2, 3, and 4 throws and surgeon's knots with 5, 6, 7, and 8 throws. A universal materials testing machine was used to test the tensile strength of suture and knots to failure, and the KHC, RKS, weight, and volume of knots were determined. RESULTS Forwarder knots had significantly higher KHC and RKS and lower volume, compared with surgeons' knots. Forwarder knots tied with fat-exposed suture had greater weight, but not volume, than did forwarder knots tied with dry or BES-exposed suture with the same number of throws. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that forwarder knots were superior to surgeon's knots when configured as start knots intended for continuous lines of suture. Exposure to media did not negatively affect mechanical or physical properties of forwarder knots and may improve specific biomechanical functions, including KHC and RKS.
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McGlinchey L, Hanson RR, Boone LH, Rosanowski SM, Coleridge M, Souza C, Munsterman AS. Bursting strength of surgeon's and self-locking knots for closure of ventral midline celiotomy in horses. Vet Surg 2018; 47:1080-1086. [PMID: 30276828 DOI: 10.1111/vsu.12957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 03/07/2018] [Accepted: 03/13/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To compare the bursting strength and failure mode of ventral midline celiotomy closed with a simple continuous suture pattern with 1 of 2 knot combinations, a novel self-locking knot combination of a forwarder start with an Aberdeen end knot (F-A) and a traditional combination of a surgeon's start with a surgeon's end knot (S-S). STUDY DESIGN Ex vivo experimental. SAMPLE POPULATION Equine cadavers (n = 14). METHODS A 20-cm ventral midline celiotomy was created in 14 equine cadavers. Horses were assigned to celiotomy closure with an F-A or S-S knot combination. Prior to closure, a 200-L inflatable bladder was placed in the abdomen and then insufflated until failure of the celiotomy closure. The horses' signalment, weight, breed, and age, as well as knot combination type, mode of failure, closure time, and bursting strength (mm Hg) were recorded. RESULTS The median bursting strength was significantly greater when incisions were closed with the F-A knot combination (388 mm Hg) compared with the S-S knot combination (290 mm Hg) (P = .035). Most incisions failed along the fascia when closed with F-A combinations and at the knot when closed with S-S combinations. CONCLUSION The bursting strength of ventral midline incisions in equine cadavers was increased by an average of 25% when closed with the self-locking F-A knot combination. CLINICAL SIGNIFICANCE Closing ventral midline celiotomies with an F-A knot combination may provide a more secure closure than the traditional S-S knot combination. Additional in vivo investigation is required prior to recommending this closure in clinical cases.
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Affiliation(s)
- Leah McGlinchey
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama
| | - R Reid Hanson
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama
| | - Lindsey H Boone
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama
| | - Sarah M Rosanowski
- Veterinary Epidemiology, Economics and Public Health Group, Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, United Kingdom
| | - Matthew Coleridge
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama
| | - Camila Souza
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, Washington
| | - Amelia S Munsterman
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
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Coleridge M, Gillen AM, Farag R, Hanson RR, Munsterman AS. Effect of fluid media on the mechanical properties of continuous pattern-ending surgeon's, square, and Aberdeen knots in vitro*. Vet Surg 2017; 46:306-315. [DOI: 10.1111/vsu.12627] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 12/08/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew Coleridge
- Department of Clinical Sciences; College of Veterinary Medicine, Auburn University; Auburn Alabama
| | - Alexandra M. Gillen
- Department of Clinical Sciences; College of Veterinary Medicine, Auburn University; Auburn Alabama
| | - Ramsis Farag
- Department of Polymer Engineering; Auburn University; Auburn Alabama
| | - R. Reid Hanson
- Department of Clinical Sciences; College of Veterinary Medicine, Auburn University; Auburn Alabama
| | - Amelia S. Munsterman
- Department of Clinical Sciences; College of Veterinary Medicine, Auburn University; Auburn Alabama
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Gillen AM, Munsterman AS, Farag R, Coleridge MOD, Hanson RR. In vitro evaluation of square and surgeon's knots in large gauge suture. Vet Surg 2017; 46:297-305. [DOI: 10.1111/vsu.12619] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/01/2016] [Accepted: 09/23/2016] [Indexed: 10/20/2022]
Affiliation(s)
- Alex M. Gillen
- Department of Clinical Sciences, College of Veterinary Medicine; Auburn University; Auburn Alabama
| | - Amelia S. Munsterman
- Department of Clinical Sciences, College of Veterinary Medicine; Auburn University; Auburn Alabama
| | - Ramsis Farag
- Center of Polymer and Composite Engineering, Samuel Ginn College of Engineering; Auburn University; Auburn Alabama
- Department of Textile Engineering, Faculty of Engineering; Mansoura University; Mansoura Egypt
| | - Matthew O. D. Coleridge
- Department of Clinical Sciences, College of Veterinary Medicine; Auburn University; Auburn Alabama
| | - R. Reid Hanson
- Department of Clinical Sciences, College of Veterinary Medicine; Auburn University; Auburn Alabama
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