Biomechanical comparison of three epitendinous suture patterns as adjuncts to a core locking loop suture for repair of canine flexor tendon injuries

Abstract

Objective To determine the effects of different epitendinous sutures (ES) in addition to core locking‐loop (LL) sutures on the mechanical properties and gap formation in a canine cadaveric tendon model. Study design Experimental, ex vivo, biomechanical study. Sample population Seventy‐two cadaveric superficial digital flexor tendon specimens. Methods Superficial digital flexor tendon specimens were divided into four groups (n = 18): sharply transected and repaired with LL, LL + simple continuous ES, LL + Silfverskiöld cross‐stitch ES, and LL + interlocking horizontal mattress ES. Constructs were loaded to monotonic failure. Failure modes, gapping, yield, peak, and failure forces were analyzed. Significance was set at P < .05. Results Yield, peak, and failure forces increased by 2.5‐fold, two‐fold, and twofold, respectively when ES groups were compared with core LL suture patterns alone (P < .0001). Resistance to 1‐ and 3‐mm gap formation was greater in ES groups compared with core LL constructs alone (P < .0001). No differences in yield, peak, failure force, or gapping were observed among ES patterns (P > .827). Conclusion Adding an ES reduced gap formation and increased yield, peak, and failure forces of tenorrhaphies. No difference was detected between the epitendinous patterns tested in this study. Clinical significance The addition of an ES seems more relevant than the specific type of pattern to improve the biomechanical properties of flexor tendon repairs. In vivo studies are warranted to determine the biological implications of the patterns tested here.

Effect of partial vs complete circumferential epitendinous suture placement on the biomechanical properties and gap formation of canine cadaveric tendons

“…An a priori power analysis was performed after completion of a pilot study using three dogs (six tendons). Based upon the failure load of previous ex vivo studies 18,19 and pilot testing conducted prior to definitive testing, a sample size calculation determined that ≥11 dogs per group would provide at least 90% power to detect a mean difference between groups of 30 ± 6 N at a 95% confidence level among independent measure. Pilot data were excluded from inclusion in the final statistical analysis.…”

“…3 Repairs with gaps >3 mm pose a greater risk for rerupture at the surgical site. 3 Researchers have demonstrated that ES use decreases the occurrence of gap formation to both 1-mm and 3-mm 18,19,34 while simultaneously increasing the tensile forces required to cause gapping between tendon ends. 26 In agreement with prior studies, use of a complete circumferential ES in groups 2 and 3 required ≈80% and 120% greater force to cause 1-mm and 3-mm gaps, respectively, compared with use of a partial circumferential ES repair alone.…”

“…Patterns include simple continuous, Silfverskiöld crossstitch, and interlocking horizontal mattress patterns, which have been shown to increase construct strength 2.5-fold compared with core suture use alone. [16][17][18][19][20] Improvement in construct strength has also been demonstrated by positioning suture bites at a great distance from the transection site. 17 Increasing the bite depth of suture into the tendinous core has also been shown to confer significant biomechanical advantages to experimental canine constructs.…”

“…[12][13][14][15] In the veterinary literature, researchers have reported superior biomechanical strength at the repair site while reducing gap formation compared with core suture use alone. [16][17][18][19] Gelberman et al 3 demonstrated that, in dogs, gap formation >3 mm increased healing times, decreased repair site strength, and increased the relative risk for tendon rerupture during the first 6 weeks after surgical intervention. Several ES suture patterns have been evaluated for use in veterinary medicine.…”

Effect of a continuous epitendinous suture as adjunct to three‐loop pulley and locking‐loop patterns for flexor tendon repair in a canine model

“…Epitendinous suture patterns improve biomechanical strength of the repair, minimize tendon gapping, and reduce the cross‐sectional area of the repaired tendon . In one study, the addition of an epitendinous suture decreased the rate of reoperation because of failure of the primary repair by 84% . Identification of novel tenorrhaphy techniques to resist gap formation at physiologic loads is a essential step in determining the efficacy and safety of surgical sutures in tendon repair prior to clinical use in dogs.…”