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- Author or Editor: Daniel J. Duffy x
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Abstract
OBJECTIVE
To determine the effects of 2-, 4-, 6- and 8-strand suture repairs on the biomechanical properties of canine gastrocnemius tenorrhaphy constructs in an ex vivo model.
SAMPLE
56 cadaveric gastrocnemius musculotendinous units from 28 adult large-breed dogs.
PROCEDURES
Tendons were randomly assigned to 4 repair groups (2-, 4-, 6- or 8-strand suture technique; n = 14/group). Following tenotomy, repairs were performed with the assigned number of strands of 2-0 polypropylene suture in a simple interrupted pattern. Biomechanical testing was performed. Yield, peak, and failure loads, the incidence of 1- and 3-mm gap formation, forces associated with gap formation, and failure modes were compared among groups.
RESULTS
Yield, peak, and failure forces differed significantly among groups, with significantly greater force required as the number of suture strands used for tendon repair increased. The force required to create a 1- or 3-mm gap between tendon ends also differed among groups and increased significantly with number of strands used. All constructs failed by mode of suture pull-through.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that increasing the number of suture strands crossing the repair site significantly increases the tensile strength of canine gastrocnemius tendon repair constructs and their resistance to gap formation. Future studies are needed to assess the effects of multistrand suture patterns on tendon glide function, blood supply, healing, and long-term clinical function in dogs to inform clinical decision-making.
Abstract
OBJECTIVE
To evaluate the effect of presurgical storage conditions on leakage pressures of enterotomy sites closed with unidirectional barbed suture material in fresh, chilled, and frozen-thawed cadaveric canine jejunal specimens.
SAMPLE
36 grossly normal jejunal segments obtained from 4 dog cadavers.
PROCEDURES
9 jejunal segments were harvested immediately from each euthanized dog and randomly assigned to be tested within 4 hours after collection (fresh segments), stored at 4°C for 24 hours before testing (chilled segments), or stored at −20°C for 7 days and thawed at 21°C for 6 hours before testing (frozen-thawed segments). For leakage pressure testing, a 3-cm-long antimesenteric enterotomy was performed and repaired with 3-0 unidirectional barbed suture material in a simple continuous pattern in each segment. Time to complete the enterotomy, initial leakage pressure, maximum intraluminal pressure, and leakage location were recorded for each segment.
RESULTS
Mean ± SD initial leakage pressure for fresh, chilled, and frozen-thawed segments was 52.8 ± 14.9 mm Hg, 51.8 ± 11.9 mm Hg, and 33.3 ± 7.7 mm Hg, respectively. Frozen-thawed segments had significantly lower mean initial leakage pressure, compared with findings for fresh or chilled segments. Time to complete the enterotomy, maximum intraluminal pressure, and leakage location did not differ among groups.
CONCLUSIONS AND CLINICAL RELEVANCE
Leak pressure testing of cadaveric jejunal segments that are fresh or chilled at 4°C for 24 hours is recommended for enterotomy studies involving barbed suture material in dogs. Freezing and thawing of cadaveric jejunal tissues prior to investigative use is not recommended because leak pressure data may be falsely low.
Abstract
OBJECTIVE
To evaluate the effect of suture caliber on the tensile strength of tenorrhaphies performed with a locking-loop technique in cadaveric canine tendons
SAMPLE
60 superficial digital flexor tendons (SDFTs) from 30 cadaveric adult dogs.
PROCEDURES
Transverse tenotomy was performed, and SDFTs were repaired with a locking-loop technique and polypropylene suture of 5 randomly assigned calibers: size-0, 2-0, 3-0, 4-0, or 5-0 (n = 12 SDFTs/suture caliber). Tendon constructs were tested to failure. Yield, peak, and failure forces and causes of failure were compared between groups.
RESULTS
Mean ± SD failure force for the constructs was significantly greater with large-caliber suture (size-0: 73.5 ± 3.1 N; size 2-0: 54.4 ± 7.1 N; size 3-0: 28.7 ± 4.9 N; size 4-0: 18.7 ± 3.4 N; and size 5-0: 8.8 ± 2.8 N). The likelihood of construct failure by suture pullout through the tendon substance increased with large-caliber suture (size-0: 12/12), whereas the likelihood of construct failure by suture breakage increased with small-caliber suture (2-0: 10/12; 3-0, 4-0, and 5-0: 12/12 each).
CONCLUSIONS AND CLINICAL RELEVANCE
Large-caliber suture had greater tensile strength for tenorrhaphies performed with a locking-loop technique in cadaveric canine tendons. Prior to the use of large-caliber suture in patients requiring tenorrhaphy, however, in vivo studies are required to confirm the results obtained here.
Abstract
OBJECTIVE
To evaluate the effect of knot location on the biomechanical strength and gapping characteristics of ex vivo canine gastrocnemius tenorrhaphy constructs.
SAMPLE
36 cadaveric gastrocnemius tendons from 18 adult dogs.
PROCEDURES
Tendons were randomly assigned to 3 groups (12 tendons/group) and sharply transected and repaired by means of a core locking-loop suture with the knot at 1 of 3 locations (exposed on the external surface of the tendon, buried just underneath the external surface of the tendon, or buried internally between the apposed tendon ends). All repairs were performed with size-0 polypropylene suture. All constructs underwent a single load-to-failure test. Yield, failure, and peak forces, mode of failure, and forces required for 1- and 3-mm gap formation were compared among the 3 knot-location groups.
RESULTS
Mean yield, failure, and peak forces and mean forces required for 1- and 3-mm gap formation did not differ significantly among the 3 groups. The mode of failure also did not differ significantly among the 3 groups, and the majority (33/36 [92%]) of constructs failed owing to the suture pulling through the tendinous substance.
CONCLUSIONS AND CLINICAL RELEVANCE
Final knot location did not significantly affect the biomechanical strength and gapping characteristics of canine gastrocnemius tenorrhaphy constructs. Therefore, all 3 evaluated knot locations may be acceptable for tendon repair in dogs. In vivo studies are necessary to further elucidate the effect of knot location in suture patterns commonly used for tenorrhaphy on tendinous healing and collagenous remodeling at the repair site.
Abstract
OBJECTIVE
To evaluate the effects of using an internal fixation plate to augment primary 3-loop pulley (3LP) repair of canine gastrocnemius tendons (GTs).
SAMPLE
48 cadaveric GTs from 24 adult dogs.
PROCEDURES
GTs were dissected free from other tissues, transected, and randomly assigned to 4 groups (n = 12/group). GTs were repaired with 2-0 polypropylene with a 3LP repair alone or a 3LP repair augmented with a 3-hole veterinary cuttable plate (3VCP), a 5-hole veterinary cuttable plate (5VCP), or a 7-hole veterinary cuttable plate (7VC P). Biomechanical loads, construct stiffness, gap formation, and failure modes were compared between groups.
RESULTS
Yield, peak, and failure loads were all significantly increased for the 5VCP and 7VCP groups, compared with the 3LP alone group. Increasing plate length from 3VCP to 5VCP and from 3VCP to 7VCP increased yield, peak, and failure loads. No differences were found between the 3LP and 3VCP groups with regard to yield and peak loads, but failure load was increased in the 3VCP group. Loads to create 1-mm and 3-mm gaps were significantly greater for the 5VCP and 7VCP groups, compared with the 3LP alone and 3VCP groups. Mode of plate attachment failure differed among groups.
CLINICAL RELEVANCE
Tendon plate augmentation may be a viable surgical option to increase the strength of the tenorrhaphy in dogs. However, in vivo studies evaluating the effects of plate augmentation on the tendon blood supply and progression of healing are needed prior to clinical application.
