Investigation of the effects of two-, four-, six- and eight-strand suture repairs on the biomechanical properties of canine gastrocnemius tenorrhaphy constructs

Author(s):  
Yi-Jen Chang ◽  
Daniel J. Duffy ◽  
George E. Moore

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.

2011 ◽  
Vol 11 (04) ◽  
pp. 845-855 ◽  
Author(s):  
BENG HAI LIM ◽  
LAI HOCK OOI ◽  
SIAW MENG CHOU ◽  
KHENG LIM GOH

A six-strand single-loop technique has been implemented for repairing extensor tendons. This paper describes an investigation to compare the biomechanical properties of extensor tendons repaired using this technique with three other commonly used techniques, namely the Kessler-Tajima (two-stand) technique, the Tsuge (two-strand) technique, and the modified (four-strand and double-loop) Tsuge technique. Epitendinous stitches were implemented on all techniques. From human cadaveric hands, extensor tendons were harvested, transected, and repaired using these techniques. Tensile test was performed on the repaired tendons to determine the force at the first gap opening, 1-mm and 2-mm gap distances and at the maximum load. We have observed that at the first gap opening, the forces generated in the tendons repaired using the six-strand, Kessler-Tajima, and modified Tsuge techniques are significantly larger than the Tsuge technique. Thereafter, the force generated at gap distances of 1 mm, 2 mm, and the maximum force depend on the number of strands and the epitendinous stitches. In this case, the maximum force (31.80 N ± 4.73 N) from the six-strand technique is significantly higher than that from the Kessler-Tajima technique. In particular, all samples from the six-strand technique failed by suture pull-out. In contrast, suture pull-out is less common for the other techniques; these samples also exhibited suture rupture. This study is important because it reveals that cadaveric tendons repaired using the Kessler-Tajima, modified Tsuge, and six-strand techniques can accommodate higher initial forces (compared to the Tsuge technique) and, thus, are more effective for resisting gap formation. Among these techniques, it is shown that the six-strand configuration is reliable because the strands, rather than breaking, results in pull-out at sufficiently high loads. Thus, the six-strand approach for anchoring the ruptured tissue results in the transfer of large forces to the suture. It is suggested that the six-strand technique may be a viable technique since it requires only a single-loop suture and this may simplify the repair procedure and tendon handling without increasing the bulk of the repaired tendon appreciably.


2020 ◽  
Vol 9 (6) ◽  
pp. 285-292
Author(s):  
Zhanwen Wang ◽  
Hong Li ◽  
Zeling Long ◽  
Subin Lin ◽  
Andrew R. Thoreson ◽  
...  

Aims Many biomechanical studies have shown that the weakest biomechanical point of a rotator cuff repair is the suture-tendon interface at the medial row. We developed a novel double rip-stop (DRS) technique to enhance the strength at the medial row for rotator cuff repair. The objective of this study was to evaluate the biomechanical properties of the DRS technique with the conventional suture-bridge (SB) technique and to evaluate the biomechanical performance of the DRS technique with medial row knots. Methods A total of 24 fresh-frozen porcine shoulders were used. The infraspinatus tendons were sharply dissected and randomly repaired by one of three techniques: SB repair (SB group), DRS repair (DRS group), and DRS with medial row knots repair (DRSK group). Specimens were tested to failure. In addition, 3 mm gap formation was measured and ultimate failure load, stiffness, and failure modes were recorded. Results The mean load to create a 3 mm gap formation in the DRSK and DRS groups was significantly higher than in the SB group. The DRSK group had the highest load to failure with a mean ultimate failure load of 395.0 N (SD 56.8) compared to the SB and DRS groups, which recorded 147.1 N (SD 34.3) and 285.9 N (SD 89.8), respectively (p < 0.001 for both). The DRS group showed a significantly higher mean failure load than the SB group (p = 0.006). Both the DRS and DRSK groups showed significantly higher mean stiffness than the SB group. Conclusion The biomechanical properties of the DRS technique were significantly improved compared to the SB technique. The DRS technique with medial row knots showed superior biomechanical performance than the DRS technique alone.


2016 ◽  
Vol 04 (01) ◽  
pp. 16-20 ◽  
Author(s):  
Philip Zeplin ◽  
M. Henle ◽  
R. Zahn ◽  
R. Meffert ◽  
K. Schmidt

2020 ◽  
Author(s):  
Jaewon Lee ◽  
Vincent Bernard ◽  
Alexander Semaan ◽  
Maria Monberg ◽  
Jonathan Huang ◽  
...  

Abstract Precision medicine approaches in pancreatic ductal adenocarcinoma (PDAC) are imperative for improving disease outcomes. However, the long-term fidelity of recently deployed ex vivo preclinical platforms, such as patient-derived organoids (PDOs), remains unknown. Through single-cell RNA sequencing (scRNA-seq), we identify substantial transcriptomic evolution of PDOs propagated from the parental tumor, which may alter predicted drug sensitivity. In contrast, scRNA-seq is readily applicable to limited biopsies from human primary and metastatic PDAC and identifies most cancers as being an admixture of previously described epithelial transcriptomic subtypes. Integrative analyses of our data provide an in-depth characterization of the heterogeneity within the tumor microenvironment, including cancer-associated fibroblast (CAF) subclasses, and predict a multitude of ligand-receptor interactions, revealing potential targets for immunotherapy approaches. While PDOs continue to enable prospective therapeutic prediction, our analysis also demonstrates the complementarity of using orthogonal de novo biopsies from PDAC patients paired with scRNA-seq to inform clinical decision-making.


2011 ◽  
Vol 36 (6) ◽  
pp. 461-466 ◽  
Author(s):  
S. P. Fuchs ◽  
E. T. Walbeehm ◽  
S. E. R. Hovius

The purpose of this study was to compare the biomechanical properties of a novel wrap around tendon repair method with those of the standard Pulvertaft technique used for tendon reconstructions. Seventy-two porcine extensor tendons were used to create 36 reconstructions in six sets of six repairs, each using one of the two surgical techniques with differing lengths of the reconstructions. All the reconstructions were tested in vitro by cyclic tensile loading, resulting in the time-zero strength. When only the size of the repair and the strength were compared, and length of the reconstruction was not taken in consideration, the ‘wrap around’ reconstructions were of similar strength but less bulky than the Pulvertaft repairs. In conclusion, the ‘wrap around’ technique gives a thinner reconstruction which is as strong as, or stronger than the Pulvertaft technique, depending on the amount of weaves.


2019 ◽  
Vol 14 (1) ◽  
Author(s):  
William McCartney ◽  
Ciprian Ober ◽  
Maria Benito ◽  
Bryan MacDonald

Abstract Background The common calcanean tendon (Achilles tendon) is the strongest and largest tendon and is one of the most commonly affected by spontaneous rupture. Different suture techniques are used to repair the tendon rupture. We compare the biomechanical properties of three different modalities of suture pattern in a mechanical experiment in rabbits with the purpose of evaluating the use of polypropylene mesh augmentation for Achilles tendon repair to find out the best surgical option. Methods The study tests single cycle to failure tensile strength characteristics of three different combinations of the 3-loop pulley (3-LP) suture technique with polypropylene mesh, and statistically compares the biomechanical properties as the maximum load at failure for all 3-LP repair. Results The normal Achilles tendon—control group—failed at a mean load of 25.5 + 13.6; the experimental groups failed at a significantly lower load (p < 0.001), with the group of 3-LP suture with polypropylene mesh included in the suture being the more similar to controls, but all the groups exhibited statistically significant differences with regard to normal tendons (p < 0.001). The distance at which each group failed was also significant between control and experimental groups (p < 0.001) with the exception of the suture-only group and the group with the mesh over the suture (p = 0.15). Conclusion Results from this study suggest that incorporating the mesh within the suture provides benefit to the Achilles tendon repair by improving strength and resistance to pull through. However, further in vivo studies will be necessary to confirm these results and incorporate this technique to the routine human and veterinary surgery.


2019 ◽  
Author(s):  
John R. Ferdinand ◽  
Morvern I. Morrison ◽  
Anders Andreasson ◽  
Catriona Charlton ◽  
Alisha Chhatwal ◽  
...  

AbstractTransplantation is an effective treatment for end-stage lung disease but donor organ shortage is a major problem. Ex-vivo lung perfusion (EVLP) of marginal organs enables functional assessment under normothermic conditions to facilitate clinical decision-making around utilisation, but the molecular processes occurring during EVLP, and how they differ between more or less viable lungs, remains to be determined. Here we used RNA sequencing to delineate changes in gene expression occurring in n=10 donor lungs undergoing EVLP, comparing lungs that were deemed transplantable (n=6) to those deemed unusable (n=4). We found that lungs deemed suitable for transplantation following EVLP had reduced induction of a number of innate immune pathways during EVLP, but a greater increase in genes involved in oxidative phosphorylation, a critical ATP-degenerating pathway. Furthermore, SCGB1A1, a gene encoding an anti-inflammatory secretoglobin CC10, and other club cell genes were significantly increased in transplantable lungs following perfusion, whilst CHIT-1 was decreased. Using a larger validation cohort (n=18), we confirmed that the ratio of CHIT1 and SCGB1A1 protein levels in lung perfusate have potential utility to distinguish transplantable and non-transplantable lungs (AUC 0.81). Together, our data identify novel biomarkers that may assist with pre-transplant lung assessment, as well as pathways that may amenable to therapeutic intervention during EVLP.Single sentence summaryTranscriptional changes in lungs undergoing ex vivo normothermic perfusion identify chitinase1 and club cell genes as potential biomarkers to guide utilisation


2017 ◽  
Author(s):  
◽  
Farrah Ann Monibi

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Musculoskeletal injuries are a common and significant problem in orthopaedic practice. Despite advances in orthopaedic surgery, effective treatments for injuries to the knee meniscus remain a common and significant clinical challenge. Tissue engineering is a developing field that aims to regenerate injured tissues with a combination of cells, scaffolds, and signals. Many natural and synthetic scaffold materials have been developed and tested for the repair and restoration of a number of musculoskeletal tissues. Among these, biological scaffolds derived from extracellular matrix (ECM) have been developed and tested given the critical role of the ECM for maintaining the biological and biomechanical properties, structure, and function of native tissues. Decellularized scaffolds composed of ECM hold promise for repair and regeneration of the meniscus given the potential for ECM-based biomaterials to aid in cell recruitment, infiltration, and differentiation. The objectives of this research were to decellularize canine menisci in order to fabricate a micronized, ECM-derived scaffold, and to determine the cytocompatibility and repair potential of the scaffold ex vivo by developing an in vitro model for meniscal repair. In the first series of experiments, menisci were decellularized with a combination of physical agitation and chemical treatments. For scaffold fabrication, decellularized menisci were cryoground into a powder and the size and morphology of the ECM particles were evaluated using scanning electron microscopy. Histologic and biochemical analyses of the scaffold confirmed effective decellularization with loss of proteoglycan from the tissue but no significant reduction in collagen content. When washed effectively, the decellularized scaffold was cytocompatible to meniscal fibrochondrocytes, synoviocytes, and whole meniscal tissue based on the resazurin reduction assay, fluorescent live/dead staining, and histologic evaluation. Further, the scaffold supported cellular attachment and proliferation when combined with platelet rich plasma, and promoted an upregulation of genes associated with meniscal ECM synthesis and tissue repair. In an ex vivo model for meniscal repair, radial tears repaired and augmented with the scaffold demonstrated increased cellular proliferation and tissue repair compared to non-augmented repairs. Therefore, a micronized scaffold derived from decellularized meniscus may be a viable biomaterial for promoting avascular meniscal healing. However, further studies are necessary to determine an optimal carrier for delivery of the scaffold, and to examine the potential for the scaffold to induce cellular differentiation and functional meniscal fibrochondrogenesis.


Author(s):  
QiCai Jason Hoon ◽  
Tian Wang ◽  
Evelyn Hall ◽  
William R. Walsh ◽  
Kenneth A. Johnson

Abstract Objective The study aims to evaluate the biomechanical properties of feline femora with craniocaudal screw-hole defects of increasing diameter, subjected to three-point bending and torsion to failure at two different loading rates. Study Design Eighty femoral pairs were harvested from adult cat cadavers. For each bending and torsional experiment, there were five groups (n = 8 pairs) of increasing craniocaudal screw-hole defects (intact, 1.5 mm, 2.0 mm, 2.4 mm, 2.7mm). Mid-diaphyseal bicortical defects were created with an appropriate pilot drill-hole and tapped accordingly. Left and right femora of each pair were randomly assigned to a destructive loading protocol at low (10 mm/min; 0.5 degrees/s) or high rates (3,000 mm/min; 90 degrees/s) respectively. Stiffness, load/torque-to-failure, energy-to-failure and fracture morphology were recorded. Results Defect size to bone diameter ratio was significantly different between defect groups within bending and torsional experiments respectively (intact [0%; 0%], 1.5 mm [17.8%; 17.1%], 2.0 mm [22.8%; 23.5%], 2.4 mm [27.8%; 27.6%], 2.7 mm [31.1%; 32.4%]) (p < 0.001). No significant differences in stiffness and load/torque-to-failure were noted with increasing deficit sizes in all loading conditions. Screw-hole (2.7 mm) defects up to 33% bone diameter had a maximum of 20% reduction in bending and torsional strength compared with intact bone at both loading rates. Stiffness and load/torque-to-failure in both bending and torsion were increased in bones subjected to higher loading rates (p < 0.001). Conclusion Screw-hole defects up to 2.7 mm did not significantly reduce feline bone failure properties in this ex vivo femoral study. These findings support current screw-size selection guidelines of up to 33% bone diameter as appropriate for use in feline fracture osteosynthesis.


2020 ◽  
Vol 33 (03) ◽  
pp. 205-211 ◽  
Author(s):  
Christina J. Cocca ◽  
Daniel J. Duffy ◽  
Mariana E. Kersh ◽  
George E. Moore

Abstract Objective This article evaluates the effect of an interlocking horizontal mattress epitendinous suture (IHMES) in addition to a three-loop pulley (3LP) core suture for canine tendon repair. Study Design Twenty-eight cadaveric common calcaneal tendons were randomized, sharply transected and repaired with either a 3LP or 3LP + IHMES. Tensile loads required to create a 1- and 3-mm gap, yield, peak and failure loads, and mode of failure were analysed. Significance was set at p < 0.05. Results Mean ± standard deviation yield and failure force for 3LP + IHMES was 178.0 ± 45.3 N and 242.1 ± 47.8 N, respectively, which was significantly greater compared with 3LP alone, 97.9 ± 36.2 N and 119.3 ± 35.6 N (p < 0.0001). Occurrence of 3-mm gap formation was significantly less in the 3LP + IHMES group (p < 0.013). Mode of failure was significantly different between the groups (p < 0.001) with 3LP + IMHES patterns failing by suture breakage (13/14) compared with suture pull-through in the 3LP (11/14). Conclusion Addition of an epitendinous suture pattern significantly reduced gap formation between tendon ends and significantly increased loads at yield (1.8 × ), peak (2.0 × ) and failure (2.0 × ) force of repairs. Use of an epitendinous suture should be considered to significantly increase biomechanical strength of repairs; however, further in vivo testing is necessary to evaluate its effect on tendinous blood supply.


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