In Vitro Biomechanical Testing of the Tube Knot

2016 ◽  
Vol 45 (7) ◽  
pp. 962-967 ◽  
Author(s):  
Stephany Chang ◽  
Fanglong Dong ◽  
Minette Lagman ◽  
Peggy L. Schmidt ◽  
Kristopher L. Irizarry ◽  
...  
Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 733
Author(s):  
Milan Krticka ◽  
Ladislav Planka ◽  
Lucy Vojtova ◽  
Vladimir Nekuda ◽  
Premysl Stastny ◽  
...  

Many growth factors have been studied as additives accelerating lumbar fusion rates in different animal models. However, their low hydrolytic and thermal stability both in vitro and in vivo limits their workability and use. In the proposed work, a stabilized vasculogenic and prohealing fibroblast growth factor-2 (FGF2-STAB®) exhibiting a functional half-life in vitro at 37 °C more than 20 days was applied for lumbar fusion in combination with a bioresorbable scaffold on porcine models. An experimental animal study was designed to investigate the intervertebral fusion efficiency and safety of a bioresorbable ceramic/biopolymer hybrid implant enriched with FGF2-STAB® in comparison with a tricortical bone autograft used as a gold standard. Twenty-four experimental pigs underwent L2/3 discectomy with implantation of either the tricortical iliac crest bone autograft or the bioresorbable hybrid implant (BHI) followed by lateral intervertebral fixation. The quality of spinal fusion was assessed by micro-computed tomography (micro-CT), biomechanical testing, and histological examination at both 8 and 16 weeks after the surgery. While 8 weeks after implantation, micro-CT analysis demonstrated similar fusion quality in both groups, in contrast, spines with BHI involving inorganic hydroxyapatite and tricalcium phosphate along with organic collagen, oxidized cellulose, and FGF2- STAB® showed a significant increase in a fusion quality in comparison to the autograft group 16 weeks post-surgery (p = 0.023). Biomechanical testing revealed significantly higher stiffness of spines treated with the bioresorbable hybrid implant group compared to the autograft group (p < 0.05). Whilst histomorphological evaluation showed significant progression of new bone formation in the BHI group besides non-union and fibrocartilage tissue formed in the autograft group. Significant osteoinductive effects of BHI based on bioceramics, collagen, oxidized cellulose, and FGF2-STAB® could improve outcomes in spinal fusion surgery and bone tissue regeneration.


2013 ◽  
Vol 28 (8) ◽  
pp. 1264-1273 ◽  
Author(s):  
Andreas Weizbauer ◽  
Christian Modrejewski ◽  
Sabine Behrens ◽  
Helmut Klein ◽  
Patrick Helmecke ◽  
...  

2020 ◽  
Vol 33 (05) ◽  
pp. 301-307
Author(s):  
Masakazu Shimada ◽  
Tetsuya Takagi ◽  
Nobuo Kanno ◽  
Satoshi Yamakawa ◽  
Hiromichi Fujie ◽  
...  

Abstract Objective The aim of the study was to determine the changes in biomechanical characteristics following tibial plateau levelling osteotomy (TPLO) using simulated manual tests. Study Design Twenty-one stifles from healthy Beagle dogs that had undergone TPLO or had not (control) were first tested in the intact form, and then the cranial cruciate ligament (CrCL) was transected in each to provide four test situations: control-intact, control-CrCL-transected, TPLO-intact and TPLO-CrCL-transected. The stifles were then analysed using a robotic joint biomechanical testing system. The craniocaudal drawer, axial rotation and proximal compression tests were applied. Results The craniocaudal displacement during the drawer test was not significantly different between the control-intact and TPLO-intact. However, the displacement was significantly greater in the TPLO-CrCL-transected than in the control-intact. In the axial rotation test, the internal–external (IE) rotation was significantly greater in the TPLO-intact than in the control-intact. Similarly, the IE rotation was significantly greater in the TPLO-CrCL-transected than in the control-CrCL-transected. In the proximal compression test, craniocaudal displacement was not significantly different among the control-intact, TPLO-intact and TPLO-CrCL-transected. Conclusion These findings suggest that TPLO influences the tension of the collateral ligaments and might generate laxity of the tibiofemoral joint. Instability after the osteotomy might be associated with the progression of osteoarthritis.


2019 ◽  
Vol 109 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Alfred Gatt ◽  
Pierre Schembri-Wismayer ◽  
Nachiappan Chockalingam ◽  
Cynthia Formosa

Background: In vitro biomechanical testing of the human foot often involves the use of fresh frozen cadaveric specimens to investigate interventions that would be detrimental to human subjects. The Thiel method is an alternative embalming technique that maintains soft-tissue consistency similar to that of living tissue. However, its suitability for biomechanical testing is unknown. Thus, the aim of this study was to determine whether Thiel-embalmed foot specimens exhibit kinematic and kinetic biomechanical properties similar to those of fresh frozen specimens. Methods: An observational study design was conducted at a university biomechanics laboratory. Three cadavers had both limbs amputated, with one being fresh frozen and the other preserved by Thiel's embalming. Each foot was tested while undergoing plantarflexion and dorsiflexion in three states: unloaded and under loads of 10 and 20 kg. Their segment kinematics and foot pressure mapping were assessed simultaneously. Results: No statistically significant differences were detected between fresh frozen and Thiel-embalmed sample pairs regarding kinematics and kinetics. Conclusions: These findings highlight similar kinematic and kinetic properties between fresh frozen and Thiel-embalmed foot specimens, thus possibly enabling these specimens to be interchanged due to the latter specimens' advantage of delayed decomposition. This can open innovative opportunities for the use of these specimens in applications related to the investigation of dynamic foot function in research and education.


2006 ◽  
Vol 4 (3) ◽  
pp. 206-212 ◽  
Author(s):  
Ung-Kyu Chang ◽  
Jesse Lim ◽  
Daniel H. Kim

Object Advances in the design of a smaller-diameter rod system for use in the thoracolumbar region prompted the authors to undertake this biomechanical study of two different thoracolumbar implants. Methods In vitro biomechanical testing was performed using human cadaveric spines. All specimens were loaded to a maximum moment of 5 Nm with 300-N axial preload in six modes of motion. Two types of anterior implants with different rod diameters were applied to intact T10–12 specimens in two groups. The loading was repeated and the range of motion (ROM) was measured. A T-11 corpectomy was then performed and a strain gauge–mounted carbon fiber stackable cage was implanted. The ROM and compression force on the cage were measured, and the mean values were compared between these two groups. With stabilization of the intact spine, ROM decreased least in extension and greatest in bending compared with the intact specimens. After corpectomy and stabilization, ROM increased in extension by 104.89 ± 53.09% in specimens with a 6.35-mm rod insertion and by 83.81 ± 16.96% in those with a 5.5-mm rod, respectively; in flexion, ROM decreased by 26.98 ± 27.43% (6.35 mm) and by 9.59 ± 15.42% (5.5 mm), respectively; and in bending and rotation, both groups each showed a decrease in ROM. The load sharing of the cage was similar between the two groups (the 6.35-mm compared with 5.5-mm rods): 47.44 and 44.73% (neutral), 49.16 and 39.02% (extension), 61.90 and 56.88% (flexion), respectively. Conclusions There were no statistical differences in the ROM and load sharing of the cage when either the 6.35-or 5.5-mm-diameter dual-rod was used.


2015 ◽  
Vol 8 (3) ◽  
pp. 171-178 ◽  
Author(s):  
LeandroStocco Baccarin ◽  
Renato Correa Viana Casarin ◽  
JorgeVicente Lopes-da-Silva ◽  
LuisAugusto Passeri

The aim of this study was to assess through biomechanical testing if different synthetic materials used to fabricate test specimens have a different biomechanical behavior in comparison with other materials when simulating in vitro load resistance of a fixation method established for sagittal split ramus osteotomy (SSRO). Thirty synthetic and standardized human hemimandible replicas with SSRO were divided into three groups of 10 samples each. Group A—ABS plastic; Group B—polyamide; and Group C—polyurethane. These were fixated with three bicortical position screws (16 mm in length, 2.0-mm system) in an inverted L pattern using perforation guide and 5-mm advancement. Each sample was submitted to linear vertical load, and load strength values were recorded at 1, 3, 5, 7, and 10 mm of displacement. The means and standard deviation were compared using the analysis of variance ( p < 0.05) and the Tukey test. A tendency for lower values was observed in Group B in comparison with Groups A and C. At 3 and 5 mm of displacement, a difference between Groups A and C was found in comparison with Group B ( p < 0.05). At 7 and 10 mm of displacement, a difference was found among the three groups, in which Group C showed the highest values and Group B the lowest ( p < 0.05). Taking into consideration the results obtained and the behavior of each material used as a substrate, significant differences occurred among the materials when compared among them.


2013 ◽  
Vol 26 (05) ◽  
pp. 385-391 ◽  
Author(s):  
M. S. Bali ◽  
M. Doherr ◽  
D. Spreng ◽  
U. Rytz ◽  
S. J. Ferguson ◽  
...  

SummaryObjective: To biomechanically test the properties of three different Universal Micro External Fixator (UMEX™) configurations with regard to their use in very small animals (<5kg) and compare the UMEX system to the widely used IMEX External Skeletal Fixation (SK™) system in terms of stiffness, space needed for pin placement and weight.Methods: Three different UMEX configurations (type Ia, type Ib, and type II modified) and one SK configuration type Ia were used to stabilize Delrin plastic rods in a 1 cm fracture gap model. These constructs were tested in axial compression, craniocaudal bending, mediolateral bending, and torsion. Testing was conducted within the elastic range and mean stiffness in each mode was determined from the slope of the linear portion of the load-deformation curve. A Kruskal Wallis one-way analysis of variance on ranks test was utilized to assess differences between constructs (p <0.05).Results: The UMEX type II modified configuration was significantly stiffer than the other UMEX configurations and the SK type Ia, except in craniocaudal bending, where the SK type Ia configuration was stiffer than all UMEX constructs. The UMEX type Ia configuration was significantly the weakest of those frames. The UMEX constructs were lighter and smaller than the SK, thus facilitating closer pin placement.Conclusions: Results supported previous reports concerning the superiority of more complex constructs regarding stiffness. The UMEX system appears to be a valid alternative for the treatment of long-bone fractures in very small animals.


2008 ◽  
Vol 8 (5) ◽  
pp. 717-722 ◽  
Author(s):  
Christian P. DiPaola ◽  
Justin A. Jacobson ◽  
Hani Awad ◽  
Bryan P. Conrad ◽  
Glenn R. Rechtine

2009 ◽  
Vol 31 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Philip Schöttle ◽  
Ioannis Goudakos ◽  
Nikolaus Rosenstiel ◽  
Jan-Erik Hoffmann ◽  
William R. Taylor ◽  
...  

2014 ◽  
Vol 20 (4) ◽  
pp. 387-395 ◽  
Author(s):  
Sabrina A. Gonzalez-Blohm ◽  
James J. Doulgeris ◽  
Kamran Aghayev ◽  
William E. Lee ◽  
Jake Laun ◽  
...  

Object Through in vitro biomechanical testing, the authors compared the performance of a vertically expandable lateral lumbar interbody cage (EC) under two different torque-controlled expansions (1.5 and 3.0 Nm) and with respect to an equivalent lateral lumbar static cage (SC) with and without pedicle screw fixation. Methods Eleven cadaveric human L2–3 segments were evaluated under the following conditions: 1) intact; 2) discectomy; 3) EC under 1.50 Nm of torque expansion (EC-1.5Nm); 4) EC under 3.00 Nm of torque expansion (EC-3.0Nm); 5) SC; and 6) SC with a bilateral pedicle screw system (SC+BPSS). Load-displacement behavior was evaluated for each condition using a combination of 100 N of axial preload and 7.5 Nm of torque in flexion and extension (FE), lateral bending (LB), and axial rotation (AR). Range of motion (ROM), neutral zone stiffness (NZS), and elastic zone stiffness (EZS) were statistically compared among conditions using post hoc Wilcoxon signed-rank comparisons after Friedman tests, with a significance level of 0.05. Additionally, any cage height difference between interbody devices was evaluated. When radiographic subsidence was observed, the specimen's data were not considered for the analysis. Results The final cage height in the EC-1.5Nm condition (12.1 ± 0.9 mm) was smaller (p < 0.001) than that in the EC-3.0Nm (13.9 ± 1.1 mm) and SC (13.4 ± 0.8 mm) conditions. All instrumentation reduced (p < 0.01) ROM with respect to the injury and increased (p ≤ 0.01) NZS in flexion, extension, and LB as well as EZS in flexion, LB, and AR. When comparing the torque expansions, the EC-3.0Nm condition had smaller (p < 0.01) FE and AR ROM and greater (p ≤ 0.04) flexion NZS, extension EZS, and AR EZS. The SC condition performed equivalently (p ≥ 0.10) to both EC conditions in terms of ROM, NZS, and EZS, except for EZS in AR, in which a marginal (p = 0.05) difference was observed with respect to the EC-3.0Nm condition. The SC+BPSS was the most rigid construct in terms of ROM and stiffness, except for 1) LB ROM, in which it was comparable (p = 0.08) with that of the EC-1.5Nm condition; 2) AR NZS, in which it was comparable (p > 0.66, Friedman test) with that of all other constructs; and 3) AR EZS, in which it was comparable with that of the EC-1.5Nm (p = 0.56) and SC (p = 0.08) conditions. Conclusions A 3.0-Nm torque expansion of a lateral interbody cage provides greater immediate stability in FE and AR than a 1.5-Nm torque expansion. Moreover, the expandable device provides stability comparable with that of an equivalent (in size, shape, and bone-interface material) SC. Specifically, the SC+BPSS construct was the most stable in FE motion. Even though an EC may seem a better option given the minimal tissue disruption during its implantation, there may be a greater chance of endplate collapse by over-distracting the disc space because of the minimal haptic feedback from the expansion.


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