Effect of bite depth of an epitendinous suture on the biomechanical strength of repaired canine flexor tendons

Abstract

OBJECTIVE To determine effects of bite depth for placement of an epitendinous suture on the biomechanical strength and gap formation of repaired canine tendons. SAMPLE 48 superficial digital flexor tendons (SDFTs) obtained from 24 canine cadavers. PROCEDURES Tendons were assigned to 3 groups (16 tendons/group). Each SDFT was transected and then repaired with a continuous epitendinous suture placed with a bite depth of 1, 2, or 3 mm for groups 1, 2, and 3, respectively. Specimens were loaded to failure. Failure mode, gap formation, yield force, peak force, and failure force were analyzed. RESULTS Yield, peak, and failure forces differed significantly between groups 1 and 3 and groups 2 and 3 but not between groups 1 and 2. Comparison of the force resisted at 1 and 3 mm of gapping revealed a significant difference between groups 1 and 3 and groups 2 and 3 but not between groups 1 and 2. Failure mode did not differ among groups; suture pull-through occurred in 43 of 48 (89.6%) specimens. CONCLUSIONS AND CLINICAL RELEVANCE Increasing bite depth of an epitendinous suture toward the center of the tendon substance increased repair site strength and decreased the incidence of gap formation. Repair of tendon injuries in dogs by use of an epitendinous suture with bites made deep into the tendon should result in a stronger repair, which potentially would allow loading and rehabilitation to begin sooner after surgery. Suture techniques should be investigated in vivo to determine effects on tendinous healing and blood supply before clinical implementation.

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

“…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.…”

Influence of Interlocking Horizontal Mattress Epitendinous Suture Placement on Tendinous Biomechanical Properties in a Canine Common Calcaneal Laceration Model

“…Depth of epitendinous suture placement within the body of the tendon also served as a limitation as it has been previously shown that differing levels of penetration significantly affect the strength of the repair. 13 It should be noted that core suture size utilized in this study was larger than those typically used for human flexor zone II tendon repair. Suture size may have contributed to increased loads to failure observed in our study.…”

“…Ideal characteristics of a primary suture tendon repair include, but are not limited to, a simple technique, reliable fixation method, provision of adequate tensile strength, minimal gap formation, good tendon apposition and conservation of tendon vascularity. 24 Epitendinous repairs provide many of these attributes and their importance has been repeatedly demonstrated as they provide up to a 50% increase in repair site strength [10][11][12][13][14][15]25 and resistance to gap formation by 165% over core suture use alone. 26 Results of the present study are in accordance with previous investigations, where IHMES addition to a core 3LP suture significantly increased mean yield, peak and failure forces by 180, 200 and 200%, respectively.…”

“…8,9 Epitendinous suture repair were originally introduced to 'tidy up' the repair site, but more recently have proven to be an important structural component of the sutured repair by significantly improving the biomechanical strength of the construct and minimizing gap formation. [10][11][12][13][14][15] One study found the addition of an epitendinous suture decreased rate of reoperation due to failure of the primary repair by 84%. 16 Although the addition of epitendinous suture patterns can augment and improve the biomechanical strength and gapping characteristics of repairs, a strong primary core suture remains a necessary component to achieve functional union and clinical success following tendon rupture.…”