Kinematic and Kinetic Comparison of Fresh Frozen and Thiel-Embalmed Human Feet for Suitability for Biomechanical Educational and Research Settings

2019 ◽  
Vol 109 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Alfred Gatt ◽  
Pierre Schembri-Wismayer ◽  
Nachiappan Chockalingam ◽  
Cynthia Formosa
Keyword(s):  
Human Subjects ◽  
Biomechanical Testing ◽  
Biomechanical Properties ◽  
Kinetic Properties ◽  
Foot Pressure ◽  
Human Foot ◽  
Observational Study Design ◽  
Fresh Frozen ◽  
Research And Education

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.

Biomechanical Testing of Distal Radius Fracture Treatments: Boundary Conditions Significantly Affect the Outcome of In Vitro Experiments

2016 ◽  
Vol 32 (2) ◽  
pp. 210-214 ◽  
Author(s):  
Alexander Synek ◽  
Yan Chevalier ◽  
Christian Schröder ◽  
Dieter H. Pahr ◽  
Sebastian F. Baumbach
Keyword(s):  
Boundary Conditions ◽  
Distal Radius Fracture ◽  
Distal Radius ◽  
Plate Osteosynthesis ◽  
Biomechanical Testing ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Radius Fracture ◽  
Compression Tests

The variety of experimental setups used during in vitro testing of distal radius fracture treatments impairs interstudy comparison and might lead to contradictory results. Setups particularly differ with respect to their boundary conditions, but the influence on the experimental outcome is unknown. The aim of this biomechanical study was to investigate the effects of 2 common boundary conditions on the biomechanical properties of an extra-articular distal radius fracture treated using volar plate osteosynthesis. Uniaxial compression tests were performed on 10 synthetic radii that were randomized into a proximally constrained group (ProxConst) or proximally movable group (ProxMove). The load was applied distally through a ball joint to enable distal fragment rotation. A significantly larger (ProxConst vs ProxMove) stiffness (671.6 ± 118.9 N·mm−1 vs 259.6 ± 49.4 N·mm−1), elastic limit (186.2 ± 24.4 N vs 75.4 ± 20.2 N), and failure load (504.9 ± 142.5 N vs 200.7 ± 49.0 N) were found for the ProxConst group. The residual tilt did not differ significantly between the 2 groups. We concluded that the boundary conditions have a profound impact on the experimental outcome and should be considered more carefully in both study design and interstudy comparison.

Tensile Strength of the End-Weave Flexor Tendon Repair

1994 ◽  
Vol 19 (3) ◽  
pp. 397-400 ◽  
Author(s):  
G. M. GABUZDA ◽  
J. L. LOVALLO ◽  
M. D. NOWAK
Keyword(s):  
Tensile Strength ◽  
Biomechanical Testing ◽  
Tendon Repair ◽  
Test System ◽  
Mattress Suture ◽  
Fresh Frozen ◽  
Human Cadavers ◽  
The Cross ◽  
Horizontal Mattress Suture

A study was designed to investigate the tensile strength of the end-weave method of tendon repair. Flexor tendons were removed from 13 fresh-frozen human cadavers, transected and repaired with the end-weave technique varying from one to five weaves, with two suture techniques, the commonly used horizontal mattress suture and a new method we have termed the cross stitch. The repairs were then tested in tension to failure on a Materials Test System (MTS) biomechanical testing device. Comparisons were also made to tensile strengths of intact whole tendons, tendon-bone insertions, and distal reinsertion techniques. Tensile strength increased linearly with the number of weaves for both suture methods. The cross stitch was found to have significantly greater strength per weave compared to the horizontal mattress suture ( P < 0.05). Three out of five trials of five weaves done with the cross stitch actually failed at the tendon itself first, rather than through the repair, which was the failure mode for all other trials. The results from this in vitro model suggest that active rehabilitative exercises might safely be performed in the immediate post-operative period after procedures that involve tendon weaving.

Effects of Refrigeration and Freezing on the Electromechanical and Biomechanical Properties of Articular Cartilage

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Adele Changoor ◽  
Liah Fereydoonzad ◽  
Alex Yaroshinsky ◽  
Michael D. Buschmann
Keyword(s):  
Articular Cartilage ◽  
Experimental Testing ◽  
Biomechanical Testing ◽  
Biomechanical Properties ◽  
Fresh Tissue ◽  
Testing Procedures ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

In vitro electromechanical and biomechanical testing of articular cartilage provide critical information about the structure and function of this tissue. Difficulties obtaining fresh tissue and lengthy experimental testing procedures often necessitate a storage protocol, which may adversely affect the functional properties of cartilage. The effects of storage at either 4°C for periods of 6 days and 12 days, or during a single freeze-thaw cycle at −20°C were examined in young bovine cartilage. Non-destructive electromechanical measurements and unconfined compression testing on 3 mm diameter disks were used to assess cartilage properties, including the streaming potential integral (SPI), fibril modulus (Ef), matrix modulus (Em), and permeability (k). Cartilage disks were also examined histologically. Compared with controls, significant decreases in SPI (to 32.3±5.5% of control values, p<0.001), Ef (to 3.1±41.3% of control values, p=0.046), Em (to 6.4±8.5% of control values, p<0.0001), and an increase in k (to 2676.7±2562.0% of control values, p=0.004) were observed at day 12 of refrigeration at 4°C, but no significant changes were detected at day 6. A trend toward detecting a decrease in SPI (to 94.2±6.2% of control values, p=0.083) was identified following a single freeze-thaw cycle, but no detectable changes were observed for any biomechanical parameters. All numbers are mean±95% confidence interval. These results indicate that fresh cartilage can be stored in a humid chamber at 4°C for a maximum of 6 days with no detrimental effects to cartilage electromechanical and biomechanical properties, while one freeze-thaw cycle produces minimal deterioration of biomechanical and electromechanical properties. A comparison to literature suggested that particular attention should be paid to the manner in which specimens are thawed after freezing, specifically by minimizing thawing time at higher temperatures.

Cell-Free Book-Shaped Decellularized Tendon Matrix Graft Capable of Controlled Release of BMP-12 to Improve Tendon Healing in a Rat Model

2021 ◽  
pp. 036354652199455
Author(s):  
Han Xiao ◽  
Yang Chen ◽  
Muzhi Li ◽  
Qiang Shi ◽  
Yan Xu ◽  
...  
Keyword(s):  
Rat Model ◽  
Biomechanical Testing ◽  
Tendon Healing ◽  
Biomechanical Properties ◽  
The Other ◽  
Histological Evaluation ◽  
Sprague Dawley ◽  
A Cell

Background: Achilles tendon (AT) defects often occur in traumatic and chronic injuries. Currently, no graft can satisfactorily regenerate parallel tendinous tissue at the defect site to completely restore AT function. Purpose: To develop a cell-free functional graft by tethering bone morphogenetic protein 12 (BMP-12) on a book-shaped decellularized tendon matrix (BDTM) and to determine whether this graft is more beneficial for AT defect healing than an autograft. Study Design: Controlled laboratory study. Methods: Canine patellar tendon was sectioned into a book shape and decellularized to fabricate a BDTM. The collagen-binding domain (CBD) was fused into the N-terminus of BMP-12 to synthesize a recombinant BMP-12 (CBD-BMP-12), which was tethered to the BDTM to prepare a cell-free functional graft (CBD-BMP-12/BDTM). After its tensile resistance, tenogenic inducibility, and BMP-12 release dynamics were evaluated, the efficacy of the graft for tendon regeneration was determined in a rat model. A total of 140 mature male Sprague-Dawley rats underwent AT tenotomy. The defect was reconstructed with reversed AT (autograft group), native BMP-12 tethered to an intact decellularized tendon matrix (IDTM; NAT-BMP-12/IDTM group), native BMP-12 tethered to a BDTM (NAT-BMP-12/BDTM group), CBD-BMP-12 tethered on an IDTM (CBD-BMP-12/IDTM group), and CBD-BMP-12 tethered on a BDTM (CBD-BMP-12/BDTM group). The rats were sacrificed 4 or 8 weeks after surgery to harvest AT specimens. Six specimens from each group at each time point were used for histological evaluation; the remaining 8 specimens were used for biomechanical testing. Results: In vitro CBD-BMP-12/BDTM was noncytotoxic, showed high biomimetics with native tendons, was suitable for cell adhesion and growth, and had superior tenogenic inducibility. In vivo the defective AT in the CBD-BMP-12/BDTM group regenerated more naturally than in the other groups, as indicated by more spindle-shaped fibroblasts embedded in a matrix of parallel fibers. The biomechanical properties of the regenerated AT in the CBD-BMP-12/BDTM group also increased more significantly than in the other groups. Conclusion: CBD-BMP-12/BDTM is more beneficial than autograft for healing AT defects in a rat model. Clinical Relevance: The findings of this study demonstrate that CBD-BMP-12/BDTM can serve as a practical graft for reconstructing AT defects.

Subtalar Arthrodesis Versus Flexor Digitorum Longus Tendon Transfer for Severe Flatfoot Deformity: An in Vitro Biomechanical Analysis

1997 ◽  
Vol 18 (11) ◽  
pp. 710-715 ◽  
Author(s):  
Harold B. Kitaoka ◽  
Zong Ping Luo ◽  
Kai-Nan An
Keyword(s):  
Mechanical Behavior ◽  
Tendon Transfer ◽  
Biomechanical Analysis ◽  
Flexor Digitorum Longus ◽  
Longus Tendon ◽  
Human Foot ◽  
Subtalar Arthrodesis ◽  
Fresh Frozen ◽  
Flexor Digitorum

We defined the mechanical behavior of the foot after an operation for treatment of the flatfoot deformity, subtalar arthrodesis, and compared results with those from flexor digitorum longus tendon transfer. Twelve fresh-frozen human foot specimens were used. Supporting elements were sectioned to create a flatfoot deformity. To simulate midstance phase of gait, loads were applied axially to the plantar foot and to five tendons. Reduction of deformity in metatarsal-talar, calcaneal-talar, and talar-tibial positions was achieved and was significantly greater after subtalar arthrodesis operation than after flexor digitorum longus transfer.

scholarly journals Biomechanical Evaluation of a New Suture Button Technique for Reduction and Stabilization of the Distal Tibiofibular Syndesmosis

2020 ◽  
Vol 5 (4) ◽  
pp. 247301142096914
Author(s):  
Andres Eduardo O’Daly ◽  
R. Timothy Kreulen ◽  
Sorawut Thamyongkit ◽  
Alfred Pisano ◽  
Kitchai Luksameearunothai ◽  
...  
Keyword(s):  
Conventional Method ◽  
External Rotation ◽  
Biomechanical Testing ◽  
Biomechanical Properties ◽  
New Technique ◽  
Rotational Stability ◽  
Torsional Resistance ◽  
Fresh Frozen ◽  
Biomechanical Evaluation ◽  
Stabilization Technique

Background: Stabilization methods for distal tibiofibular syndesmotic injuries present risk of malreduction. We compared reduction accuracy and biomechanical properties of a new syndesmotic reduction and stabilization technique using 2 suture buttons placed through a sagittal tunnel in the fibula and across the tibia just proximal to the incisura with those of the conventional method. Methods: Syndesmotic injury was created in 18 fresh-frozen cadaveric lower leg specimens. Nine ankles were repaired with the conventional method and 9 with the new technique. Reduction for the conventional method was performed using thumb pressure under direct visualization and for the new method by tightening both suture buttons passed through the fibular and tibial tunnels. Computed tomography was used to assess reduction accuracy. Torsional resistance, fibular rotation, and fibular translation were evaluated during biomechanical testing. Results: The new technique showed less lateral translation of the fibula on CT measurements after reduction (0.06 ± 0.06 mm) than the conventional method (0.26 ± 0.31 mm), P = .02. The new technique produced less fibular rotation during internal rotation after 0 cycles (new –2.4 ± 1.4 degrees; conventional –5.0 ± 1.2 degrees, P = .001), 100 cycles (new –2.1 ± 1.9 degrees; conventional –4.6 ± 1.4 degrees, P = .01), and 500 cycles (new –2.2 ± 1.6 degrees; conventional –5.3 ± 2.5 degrees, P = .01) and during external rotation after 100 cycles (new 3.9 ± 3.3 degrees; conventional 5.9 ± 3.5 degrees, P = .02) and 500 cycles (new 3.3 ± 3.2 degrees; conventional 6.3 ± 2.6 degrees, P = .03). Fixation failed in 3 specimens. Conclusion: The new syndesmotic reduction and fixation technique resulted in more accurate reduction of the fibula in the tibial incisura in the coronal plane and better rotational stability compared with the conventional method. Clinical Relevance: This new technique of syndesmosis reduction and stabilization may be a reliable alternative to current methods.

scholarly journals Posterolateral Plate Fixation with Pantalarlock® is More Stable than Nail Fixation in Tibiotalocalcaneal Arthrodesis in a Biomechanical Cadaver Study

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0023
Author(s):  
Natalia Gutteck
Keyword(s):  
Plate Fixation ◽  
Pearson Correlation ◽  
Biomechanical Testing ◽  
Treatment Phase ◽  
Biomechanical Properties ◽  
Cadaver Study ◽  
Postoperative Treatment ◽  
Osteoporotic Bone ◽  
Cyclic Testing ◽  
Fresh Frozen

Category: Ankle; Ankle Arthritis Introduction/Purpose: Despite the promising results of ankle joint arthroplasty, the tibiotalocalcaneal (TTC) arthrodesis remains an established procedure in treatment of combined pathology of the ankle and subtalar joint. Despite the promising results in biomechanical investigations, nonunion rates of up to 24% are described in recent studies. The objective of this work was a comparative study of the biomechanical properties of the posterolateral plate fixation with retrograde intramedullary nail fixation. Methods: Twenty four fresh-frozen human lower leg specimens (12 pairs) were used for the comparative biomechanical testing. Every specimen was preconditioned with 100N over 200 cycles. After every 250 cycles the force was increased by 50N from 200 to 600N. This was followed by cyclic loading in dorsi-/plantiflexion with 800N for 3000 cycles. All specimens were subjected to bone densitometry (DXA) and computed tomography. Results: Significantly higher number of spacimens with nails (4) failed during the cycling testing in dorsi-/plantarflexion and futher two during the cyclic testing with 800N. Two specimens with plates failed during the cyclic testing with 800N. Statistical analysis showed that the specimens with the plate were significantly more stable in each test direction. The Pearson correlation demonstrated for the specimens with plate a linear relationship between the stiffness and the determined bone density. Conclusion: We expect a considerable reduction of the pseudarthrosis rate and shorten the postoperative treatment phase in clinical set up and appropriate advantages in the treatment of high risk patients with severe deformity of the ankle, bone defects, neuropathic deformity, poor bone quality and osteoporosis. The choice of most predictable and stable implant is essential for the successful fusion. In conclusion, the posterolateral plate ostesynthesis for TTC arthrodesis is significantly stiffer compared to the nail osteosynthesis in osteoporotic bone model.

In vitro biomechanical testing of different configurations of acrylic external skeletal fixator constructs

2015 ◽  
Vol 28 (04) ◽  
pp. 227-233 ◽  
Author(s):  
S. K. Tyagi ◽  
P. Kinjavdeka ◽  
Sharma Amarpal ◽  
A. M. Pawde ◽  
T. Srivastava ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Bone Fractures ◽  
Testing Machine ◽  
Biomechanical Testing ◽  
Bending Moment ◽  
Biomechanical Properties ◽  
Clinical Situation ◽  
High Density ◽  
Significant Difference

SummaryObjective: To evaluate the in vitro biomechanical properties of four different configurations of acrylic external skeletal fixator constructs.Materials and methods: Simulated bone constructs were prepared using two segments of 20 mm ultra-high-density polyethylene rods with a gap of 5 mm. The full pins (1.5 mm) were passed through the proximal and distal segments of ultra-high-density polyethylene rods, in the same plane, parallel to each other in configuration U, and were crossed in the M1, M2 and C configurations at a 90° angle to each other. Configuration U was a single bilateral uniplanar construct, M1 was a double orthogonal bilateral construct, M2 was a double orthogonal bilateral construct with proximal and distal connecting articulations, and C was a double orthogonal bilateral construct with proximal and distal circumferential articulations. Temporary scaffolds of different external skeletal fixator configurations were constructed using commercially available polyvinyl chloride pipes (20 mm) connected and secured to the fixation pins at a fixed distance from the rods. Acrylic powder (polymer) mixed with liquid (monomer) was poured into the pipes and allowed to solidify to form the side bars and rings. The external skeletal fixator constructs were then subjected to axial compression, cranio-caudal three-point bending and torsion (n = 4 each) using a universal testing machine. Mechanical parameters, namely stress, strain, modulus of elasticity, stiffness and bending moment of fixator constructs, were determined from load-displacement curves.Results: Configuration U was the weakest and configuration C was the strongest under all the testing modes. Under compression, the M1, M2 and C configurations were similar. Under bending, a significant difference was observed among the uniplanar, multi -planar and circular configurations with no difference between M1 and M2. However, under torsion, all the external skeletal fixator configurations differed significantly.Clinical significance: The freeform external skeletal fixator using acrylic as a replacement for a metallic bar may be useful to treat bone fractures and luxations in small animals, as it is mechanically strong, lightweight, economical, and pins can be passed from any direction depending upon the clinical situation.

scholarly journals Biomechanical, Biochemical, and Cell Biological Evaluation of Different Collagen Scaffolds for Tendon Augmentation

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Carolin Gabler ◽  
Juliane Spohn ◽  
Thomas Tischer ◽  
Rainer Bader
Keyword(s):  
Biomechanical Testing ◽  
Cell Activity ◽  
Collagen Scaffold ◽  
Biomechanical Properties ◽  
Enzymatic Digestion ◽  
Biological Evaluation ◽  
Collagen Scaffolds ◽  
Beneficial Effects ◽  
Bovine Collagen

Tendon augmentation is increasingly clinically relevant due to rising amount of tendon ruptures because of the aging and more demanding population. Therefore, newly developed scaffolds based on bovine epoxide stabilized collagen maintaining the native fibril-like collagen structure were characterized and compared to two commercially available porcine collagen scaffolds. For biomechanical testing (ultimate load, ultimate stress, stiffness, and elastic modulus), bovine collagen scaffolds were hydrated and compared to reference products. Cell viability and proliferation were assessed by seeding human primary fibroblasts on each collagen-based scaffold and cultured over various time periods (3 d, 7 d, and 14 d). Live/dead staining was performed and metabolic cell activity (WST-1 assay) was measured. Biochemical degradability was investigated by enzymatic digestion. The bovine collagen scaffold showed significantly enhanced biomechanical properties. These persisted over different rehydration times. Cell biological tests revealed that the bovine collagen scaffolds support reproducible cell colonization and a significant increase in the number of viable cells during cultivation. The results are comparable with the viability and proliferation rate of cells grown on porcine reference materials. With regard to biochemical degradability, all tested materials showed comparable resistance to enzymatic degradation in vitro. Due to imitating the natural tendon structure the new scaffold material is supposed to provide beneficial effects in future clinical application.

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