Barbed versus smooth poly- propylene three-loop pulley sutures for repair of canine gastrocnemius tendon

2014 ◽  
Vol 27 (06) ◽  
pp. 436-440 ◽  
Author(s):  
T. A. Harper ◽  
M. A. Mitchell ◽  
M. S. McFadden ◽  
B. Heggem Perry ◽  
B. S. Perry

SummaryObjective: To compare the ultimate tensile strength (UTS) and load to 1 and 3 mm gap formation of smooth (3-metric) and knotless barbed (4-metric) polypropylene sutures placed in a three-loop pulley pattern for canine gastrocnemius tendon repair.Study design: In vitro.Sample size: Thirty-three paired bonetendon units with one of each pair assigned to each suture type. Barbed suture size was based on previously published materials testing results.Methods: Each unit was placed in a servohydraulic testing machine and tested under single cycle tensile loading until repair failure.Results: There was a significantly higher UTS for smooth polypropylene compared to the barbed polypropylene repairs. The loads resulting in 1 and 3 mm gaps for the barbed repairs were consistently significantly less than the corresponding smooth polypropylene repair values.Conclusion: The knotted smooth polypropylene repair was consistently stronger than the knotless barbed polypropylene repair when placed in a three-loop pulley pattern for gastrocnemius repair.Clinical significance: Knotless barbed polypropylene suture should not be considered equivalent to knotted smooth polypropylene of comparable tensile strength when placed in a three-loop pulley pattern for canine gastrocnemius tendon repair. The low failure loads of the barbed repair are probably due to failure of the barbs to anchor consistently throughout the tendon in the knotless configuration.

2000 ◽  
Vol 25 (4) ◽  
pp. 390-392 ◽  
Author(s):  
A. ASLAM ◽  
A. AFOKE

The purpose of this study was to test in vitro a new flexor tendon suture technique that has been developed to withstand the in vivo forces of active tendon motion. This new core suture technique involves locking loops in the form of a cross stitch. The new technique was tested for ultimate tensile strength and gap formation in cadaver human flexor tendons on a tensile testing machine. The new technique proved significantly stronger than the modified Kessler core suture.


2010 ◽  
Vol 31 (11) ◽  
pp. 1124-1129 ◽  
Author(s):  
Saima Aslam ◽  
Rabih O. Darouiche

Objective.To examine the mechanical integrity of hemodialysis catheters after exposure to the combination of N-acetylcysteine, ti-gecycline, and heparin, compared with that of catheters exposed to heparin alone.Methods.We used 3 types of hemodialysis catheters: polyurethane, silicone, and carbothane catheters. Catheter segments were incubated in vitro for various time intervals of up to 2 weeks either in a novel catheter lock solution (novel CLS), which consisted of N-acetylcysteine, tigecycline, and heparin, or in heparin alone (as a control). At the time of testing, each segment was rinsed and cut longitudinally into 2 sections. All catheter sections were scanned using an optical dissecting microscope to check for surface abnormalities and to measure wall thickness. We also carried out tensile strength testing of another set of catheters using a universal testing machine. Tested parameters included stress at yield, strain at yield, stress at break, strain at break, modulus of elasticity, and force at break.Results.The surfaces of catheters in both groups appeared similar by microscopy. The mean thickness of the catheter wall was not significantly different for the catheters exposed to the novel CLS and the catheters exposed to heparin (P >.05). Results for most of the tensile strength parameters tested were similar in the 2 groups of catheters at the end of 2 weeks of incubation. In particular, the force-at-break value of all tested catheters remained much greater than that recommended by industry standards.Conclusions.The use of the novel catheter lock solution did not impair the mechanical integrity or increase the propensity for fracture of hemodialysis catheters.


1998 ◽  
Vol 23 (1) ◽  
pp. 37-40 ◽  
Author(s):  
L. GORDON ◽  
M. TOLAR ◽  
K. T. VENKATESWARA RAO ◽  
R. O. RITCHIE ◽  
S. RABINOWITZ ◽  
...  

We have developed a stainless steel internal tendon anchor that is used to strengthen a tendon repair. This study tested its use in vitro to produce a repair that can withstand the tensile strength demands of early active flexion. Fresh human cadaver flexor digitorum profundus tendons were harvested, divided, and then repaired using four different techniques: Kessler, Becker or Savage stitches, or the internal tendon anchor. The internal splint repairs demonstrated a 99–270% increase in mean maximal linear tensile strength and a 49–240% increase in mean ultimate tensile strength over the other repairs. It is hoped that this newly developed internal anchor will provide a repair that will be strong enough to allow immediate active range of motion.


2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Xun Zhu ◽  
Nathan Liu ◽  
Michael J. Yaszemski ◽  
Lichun Lu

The objective of our paper was to determine the effects of composite formulation on the compressive modulus and ultimate strength of a biodegradable, in situ polymerizable poly(propylene fumarate) (PPF) and bone fiber scaffold. The following parameters were investigated: the incorporation of bone fibers (either mineralized or demineralized), PPF molecular weight, N-vinyl pyrrolidinone (NVP) crosslinker amount, benzoyl peroxide (BP) initiator amount, and sodium chloride porogen amount. Eight formulations were chosen based on a resolution III two-level fractional factorial design. The compressive modulus and ultimate strength of these formulations were measured on a materials testing machine. Absolute values for compressive modulus varied from 21.3 to 271 MPa and 2.8 to 358 MPa for dry and wet samples, respectively. The ultimate strength of the crosslinked composites varied from 2.1 to 20.3 MPa for dry samples and from 0.4 to 16.6 MPa for wet samples. Main effects of each parameter on the measured property were calculated. The incorporation of mineralized bone fibers and an increase in PPF molecular weight resulted in higher compressive modulus and ultimate strength. Both mechanical properties also increased as the amount of benzoyl peroxide increased or the NVP amount decreased in the formulation. Sodium chloride had a dominating effect on the increase of mechanical properties in dry samples but showed little effects in wet samples. Demineralization of bone fibers led to a decrease in the compressive modulus and ultimate strength. Our results suggest that bone fibers are appropriate as structural enforcement components in PPF scaffolds. The desired orthopaedic PPF scaffold might be obtained by changing a variety of composite formulation parameters.


2020 ◽  
pp. 146531252097240
Author(s):  
Fernanda de Souza Henkin ◽  
Luciane Macedo de Menezes ◽  
Berenice Anina Dedavid ◽  
Cátia Abdo Quintão

Objective: To compare the mechanical strength of joints made by conventional soldering with those made by alternative, more biocompatible, methods (spot, tungsten inert gas [TIG] and laser welding), and to compare the microstructural morphology of wires welded with these techniques. Design: In vitro, laboratory study. Methods: Forty stainless-steel wire segments with 0.8-mm diameter were joined by silver soldering, spot, laser and TIG welding. Ten specimens were produced for each one. Tensile strength test was performed 24 h after welding on the Emic DL2000™ universal testing machine, using a load cell of 1000 N with a crosshead speed of 10 mm/min. Results: The highest tensile strength mean values were obtained with silver soldering (532 N), next were laser (420 N), spot (301 N) and TIG (296 N) welding. Statistically significant differences were observed between the groups; the Dunn post-hoc test revealed differences between laser and spot welding ( p=0.046), laser and TIG ( p = 0.016), spot and silver ( p <0.001), and silver and TIG ( p <0.001). Conclusion: Laser welding strength is high, and comparable to silver welding. Spot and TIG techniques present comparable and significantly lower strengths. The four methods presented resistance values compatible with orthodontic use. The microstructural morphology is different for each technique. The association between the mechanical performance and the microstructure evaluation shows that laser presented the highest quality joint.


2005 ◽  
Vol 30 (4) ◽  
pp. 374-378 ◽  
Author(s):  
Y. CAO ◽  
J. B. TANG

We report a four-strand modification of the Tang technique of tendon repair that uses fewer sutures and fewer knots on the tendon surface. This repair consists of four longitudinal and two horizontal strands that form a “U” configuration within the tendon made with a single looped suture. Thirty-four fresh pig flexor tendons were divided into 3 groups and repaired with the four-strand modified Tang method, a double-looped four-strand method or a double Kessler repair (four-strand). The tendons were subjected to a single cycle of load-to-failure test in a tensile testing machine. The initial force, 2-mm gap formation force and ultimate strength of the four-strand modified Tang repair were statistically identical to those of the double looped suture and were superior to those of the double Kessler repair. Ultimate strength was 43.4 ± 4.3 N for the four-strand modified Tang method, 45.2 ± 4.0 N for the double-looped method and 39.1 ± 4.0 N for the double Kessler repair. The four-strand modification of the Tang method appears to have strength sufficient for protected active finger motion. Given our preliminary clinical experience with this method, we recommend this new and simplified technique for clinical flexor tendon repairs.


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

2008 ◽  
Vol 21 (04) ◽  
pp. 323-328 ◽  
Author(s):  
M. E. Soniat ◽  
S. Elder ◽  
R. McLaughlin ◽  
J. L. Demko

SummaryAn in vitro experimental cadaveric mechanical testing study was performed using 20 radiographically mature dogs, weighing between 18–33 kg. The aim of the study was to compare the axial pull-out strength of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the canine proximal tibia using manual and power tapping techniques. 3.5 cortical and 4.0 cancellous bone screws were inserted in canine cadaver proximal tibiae using a manual or power tapping technique. The screws were extracted using a servohydraulic materials testing machine in order to measure axial pullout strength. Axial pull-out strength was recorded relative to the total bone width and total cortical width of each tibia. The mean axial pull-out strength for all constructs was 717.8±56.5 N without any statistically significant difference among groups (p=0.4183). The groups were equal in animal body weight, cortical width and total bone width (p=0.2808). The axial pull-out strength in proportion to cortical and total bone width was not significantly different among groups (p=0.5318). Axial pull-out strengths of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the proximal tibial metaphysis were not significantly different. Axial pull-out strength was not affected by the use of power tapping in either screw type.


2001 ◽  
Vol 26 (4) ◽  
pp. 301-306 ◽  
Author(s):  
A. WADA ◽  
H. KUBOTA ◽  
K. MIYANISHI ◽  
H. HATANAKA ◽  
H. MIURA ◽  
...  

We evaluated a technique of four-strand double-modified locking Kessler flexor tendon repair in healing tendons. Seventy-two canine flexor digitorum profundus tendons in Zone 2 were repaired and evaluated following either active mobilization or immobilization at 0, 7, 14, 28 and 42 days after surgery. Fifty-six tendons were examined for gap and ultimate strength using a tensile testing machine and 16 were evaluated with standard hematoxylin and eosin, and Masson’s trichrome staining. All tendons healed without rupture or gap formation of more than 1 mm, thus demonstrating that this repair technique has enough tensile strength to withstand early active mobilization. The gap and ultimate strength of actively mobilized tendons did not decrease significantly during the first 7 days, and were significantly greater than those of immobilized tendons throughout the 42-day study period. Actively mobilized tendons healed without the extrinsic adhesions and large tendon calluses that were found in immobilized tendons.


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