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

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.

Tensile strength and early healing of self‐locking and surgeon's knots

“…3 USP polyglactin 910 is the largest gauge suture available within the Unites States and has been evaluated for RKS and KHC for self-locking knots. 17,18,19,20 While the use of an abdominal bandage precluded incisional observation during the first 72 hours after celiotomy, drainage was still identified when it was present on the basis of strike-through (horse 4). In addition, infections are generally identified after 3 to 14 days postoperatively.…”

“…Some decisions made regarding suture material chosen and use of abdominal bandages were based on common practice within our hospital to improve clinical relevance of postoperative findings. 3 USP polyglactin 910 is the largest gauge suture available within the Unites States and has been evaluated for RKS and KHC for self‐locking knots 17,18,19,20 . While the use of an abdominal bandage precluded incisional observation during the first 72 hours after celiotomy, drainage was still identified when it was present on the basis of strike‐through (horse 4).…”

“…[17][18][19]21 The forwarder start knot had higher RKS and KHC compared with a surgeon's knot, with lower volume under similar conditions. 18,20 ex vivo comparison provided evidence of greater bursting strength after closure with the self-locking knot combination compared with surgeon's knots. 12 While these knots have been advocated for human abdominal surgery to increase knot security and relieve tension, it is unknown how this translates to the biodynamics of equine linea alba in early wound healing.…”

“…Self-locking knots have been shown to have improved strength when they have been tested in large gauge suture. 12,[17][18][19][20] The Aberdeen end knot exhibited greater relative knot security (RKS) and knot holding capacity (KHC) compared with square and surgeon's knots, requiring three to four fewer throws, with a smaller knot size when they were dry and after exposure to biological media. [17][18][19]21 The forwarder start knot had higher RKS and KHC compared with a surgeon's knot, with lower volume under similar conditions.…”

“…The Aberdeen end knot exhibited greater relative knot security (RKS) and knot holding capacity (KHC) compared with square and surgeon's knots, requiring three to four fewer throws, with a smaller knot size when they were dry and after exposure to biological media 17‐19,21 . The forwarder start knot had higher RKS and KHC compared with a surgeon's knot, with lower volume under similar conditions 18,20 . ex vivo comparison provided evidence of greater bursting strength after closure with the self‐locking knot combination compared with surgeon's knots 12 .…”