An Assessment of the Tensile Properties and Technical Difficulties of Two- and Four-Strand Flexor Tendon Repairs

2005 ◽  
Vol 30 (3) ◽  
pp. 294-297 ◽  
Author(s):  
T. M. LAWRENCE ◽  
M. J. WOODRUFF ◽  
A. ALADIN ◽  
T. R. C. DAVIS
Keyword(s):  
Operative Time ◽  
Porcine Model ◽  
Flexor Tendon ◽  
Operating Time ◽  
Rupture Force ◽  
Gap Formation ◽  
Technical Ability ◽  
Single Cross ◽  
Additional Operating Time

This study compares the mechanical properties of locking Kessler and four-strand flexor tendon repairs and examines for difficulties related to technical ability. Two trainee surgeons each carried out 10 locking Kessler and 10 four-strand single-cross flexor tendon repairs on an in vitro porcine model. Outcome measures included gap formation and ultimate forces, operative time and repair bulk. Ultimate force was 81% greater for the four-strand repair compared to the Kessler (52 N, SD 5, versus 29 N, SD 6). Operating times were similar between the two techniques (Kessler 10.0 minutes, four strand 10.1 minutes). Rupture force and operating times improved slightly during the study for the Kessler repairs, but in the four strand repairs results remained stable throughout the study. We conclude that the single-cross four-strand repair tolerates superior loads yet is no more technically demanding than the modified Kessler, and can be reliably performed without additional operating time.

A Comparative Analysis of the Biomechanical Behaviour of Five Flexor Tendon Core Sutures

2004 ◽  
Vol 29 (6) ◽  
pp. 536-543 ◽  
Author(s):  
A. VIINIKAINEN ◽  
H. GÖRANSSON ◽  
K. HUOVINEN ◽  
M. KELLOMÄKI ◽  
P. ROKKANEN
Keyword(s):  
Yield Point ◽  
Flexor Tendon ◽  
Tendon Repair ◽  
Gap Formation ◽  
Linear Region ◽  
The Core ◽  
Polyester Suture ◽  
Static Tensile ◽  
Yield Force

Five core suture techniques were compared by static tensile testing in vitro. Fifty porcine tendons were used. The core sutures were performed with 3-0 or 4-0 braided polyester suture (Ticron®) and the over-and-over running peripheral sutures with 6-0 monofilament polypropylene (Prolene®). The core sutures were: (1) Pennington modified Kessler (3-0), (2) Double Pennington modified Kessler (3-0), (3) 4-strand Savage (3-0), (4) 4-strand Savage (4-0), and (5) 6-strand Savage (4-0). Repairs were compared as paired in regard to one variable: the number of core suture strands, the suture calibre, or the suture configuration. Biomechanical differences between the repair groups started during the linear region, with the yield force and stiffness increasing along with the number of core suture strands. All three variables influenced the strain at the yield point. Thus, the strength of the intact repair can be improved by modifying the core suture. In all repairs gap formation started near the yield point after failure of the peripheral suture. The yield force represents the strength of the intact repair composite and should be considered the strength of the tendon repair.

Tensile Strengths of Various Suture Techniques

1997 ◽  
Vol 22 (6) ◽  
pp. 764-767 ◽  
Author(s):  
M. D. SHAIEB ◽  
D. I. SINGER
Keyword(s):  
Flexor Tendon ◽  
Suture Techniques ◽  
Gap Formation ◽  
Flexor Digitorum Longus ◽  
Flexor Digitorum

The tensile strengths of various suture techniques were studied in vitro using rabbit Achilles’ and flexor digitorum longus tendons. Two new suture methods, a Double and Triple (modified) Kessler, were compared with the Savage, Indiana and modified Kessler techniques. All were core sutures without epitendinous sutures. All suture techniques were found to be significantly different for 2 mm of gap formation. The study found the Savage technique strongest, followed by the Triple Kessler, the Double Kessler, and finally the Indiana. The Double Kessler was almost twice as strong as the modified Kessler. This study also compared two four-stranded techniques (the Indiana and Double Kessler) and found the Double Kessler stronger. The Double Kessler is a simple yet strong suture and may be useful for flexor tendon repairs.

A New Core Suture Technique for Flexor Tendon Repair: Biomechanical Analysis of Tensile Strength and Gap Formation

2000 ◽  
Vol 25 (4) ◽  
pp. 390-392 ◽  
Author(s):  
A. ASLAM ◽  
A. AFOKE
Keyword(s):  
Tensile Strength ◽  
Flexor Tendon ◽  
Testing Machine ◽  
Suture Technique ◽  
Biomechanical Analysis ◽  
New Technique ◽  
Gap Formation ◽  
Tensile Testing Machine

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.

An in vitro model of fibroblast activity and adhesion formation during flexor tendon healing

1994 ◽  
Vol 19 (5) ◽  
pp. 769-776 ◽  
Author(s):  
David L. Packer ◽  
George W. Dombi ◽  
Ping Yang Yu ◽  
Paul Zidel ◽  
Walter G. Sullivan
Keyword(s):  
In Vitro Model ◽  
Flexor Tendon ◽  
Adhesion Formation ◽  
Tendon Healing ◽  
Vitro Model

scholarly journals Robotic-assisted cholecystectomy is superior to laparoscopic cholecystectomy in the initial training for surgical novices in an ex vivo porcine model: a randomized crossover study

2021 ◽  
Author(s):  
E. Willuth ◽  
S. F. Hardon ◽  
F. Lang ◽  
C. M. Haney ◽  
E. A. Felinska ◽  
...  
Keyword(s):  
Laparoscopic Cholecystectomy ◽  
Crossover Study ◽  
Porcine Model ◽  
Haptic Feedback ◽  
Ex Vivo ◽  
Operating Time ◽  
Surgical Performance ◽  
Robotic Assisted ◽  
Subjective Workload ◽  
Randomized Crossover Study

Abstract Background Robotic-assisted surgery (RAS) potentially reduces workload and shortens the surgical learning curve compared to conventional laparoscopy (CL). The present study aimed to compare robotic-assisted cholecystectomy (RAC) to laparoscopic cholecystectomy (LC) in the initial learning phase for novices. Methods In a randomized crossover study, medical students (n = 40) in their clinical years performed both LC and RAC on a cadaveric porcine model. After standardized instructions and basic skill training, group 1 started with RAC and then performed LC, while group 2 started with LC and then performed RAC. The primary endpoint was surgical performance measured with Objective Structured Assessment of Technical Skills (OSATS) score, secondary endpoints included operating time, complications (liver damage, gallbladder perforations, vessel damage), force applied to tissue, and subjective workload assessment. Results Surgical performance was better for RAC than for LC for total OSATS (RAC = 77.4 ± 7.9 vs. LC = 73.8 ± 9.4; p = 0.025, global OSATS (RAC = 27.2 ± 1.0 vs. LC = 26.5 ± 1.6; p = 0.012, and task specific OSATS score (RAC = 50.5 ± 7.5 vs. LC = 47.1 ± 8.5; p = 0.037). There were less complications with RAC than with LC (10 (25.6%) vs. 26 (65.0%), p = 0.006) but no difference in operating times (RAC = 77.0 ± 15.3 vs. LC = 75.5 ± 15.3 min; p = 0.517). Force applied to tissue was similar. Students found RAC less physical demanding and less frustrating than LC. Conclusions Novices performed their first cholecystectomies with better performance and less complications with RAS than with CL, while operating time showed no differences. Students perceived less subjective workload for RAS than for CL. Unlike our expectations, the lack of haptic feedback on the robotic system did not lead to higher force application during RAC than LC and did not increase tissue damage. These results show potential advantages for RAS over CL for surgical novices while performing their first RAC and LC using an ex vivo cadaveric porcine model. Registration number researchregistry6029 Graphic abstract

scholarly journals Preclinical Testing of Radiopharmaceuticals for the Detection and Characterization of Osteomyelitis: Experiences from a Porcine Model

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4221
Author(s):  
Aage Kristian Olsen Alstrup ◽  
Svend Borup Jensen ◽  
Ole Lerberg Nielsen ◽  
Lars Jødal ◽  
Pia Afzelius
Keyword(s):  
Animal Model ◽  
Animal Models ◽  
Porcine Model ◽  
Animal Experiments ◽  
Radioactive Tracers ◽  
The Individual ◽  
Selection Of

The development of new and better radioactive tracers capable of detecting and characterizing osteomyelitis is an ongoing process, mainly because available tracers lack selectivity towards osteomyelitis. An integrated part of developing new tracers is the performance of in vivo tests using appropriate animal models. The available animal models for osteomyelitis are also far from ideal. Therefore, developing improved animal osteomyelitis models is as important as developing new radioactive tracers. We recently published a review on radioactive tracers. In this review, we only present and discuss osteomyelitis models. Three ethical aspects (3R) are essential when exposing experimental animals to infections. Thus, we should perform experiments in vitro rather than in vivo (Replacement), use as few animals as possible (Reduction), and impose as little pain on the animal as possible (Refinement). The gain for humans should by far exceed the disadvantages for the individual experimental animal. To this end, the translational value of animal experiments is crucial. We therefore need a robust and well-characterized animal model to evaluate new osteomyelitis tracers to be sure that unpredicted variation in the animal model does not lead to a misinterpretation of the tracer behavior. In this review, we focus on how the development of radioactive tracers relies heavily on the selection of a reliable animal model, and we base the discussions on our own experience with a porcine model.

scholarly journals Strong Antimicrobial and Healing Effects of Beta-Acids from Hops in Methicillin-Resistant Staphylococcus aureus-Infected External Wounds In Vivo

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 708
Author(s):  
Radek Sleha ◽  
Vera Radochova ◽  
Jiri Malis ◽  
Alexander Mikyska ◽  
Milan Houska ◽  
...  
Keyword(s):  
Wound Healing ◽  
Porcine Model ◽  
Therapeutic Effects ◽  
Methicillin Resistant ◽  
Antimicrobial Effects ◽  
Therapeutic Modalities ◽  
Positive Effects ◽  
Inflammatory Parameters

Staphylococcus (S.) aureus is an important causative agent of wound infections with increasing incidence in the past decades. Specifically, the emergence of methicillin-resistant S. aureus (MRSA) causes serious problems, especially in nosocomial infections. Therefore, there is an urgent need to develop of alternative or supportive antimicrobial therapeutic modalities to meet these challenges. Purified compounds from hops have previously shown promising antimicrobial effects against MRSA isolates in vitro. In this study, purified beta-acids from hops were tested for their potential antimicrobial and healing properties using a porcine model of wounds infected by MRSA. The results show highly significant antimicrobial effects of the active substance in both the powder and Ambiderman-based application forms compared to both no-treatment control and treatment with Framycoin. Moreover, the macroscopic evaluation of the wounds during the treatment using the standardized Wound Healing Continuum indicated positive effects of the beta-acids on the overall wound healing. This is further supported by the microscopic data, which showed a clear improvement of the inflammatory parameters in the wounds treated by beta-acids. Thus, using the porcine model, we demonstrate significant therapeutic effects of hops compounds in the management of wounds infected by MRSA. Beta-acids from hops, therefore, represent a suitable candidate for the treatment of non-responsive nosocomial tissue infections by MRSA.

scholarly journals Development of a gel dedicated to gel immersion endoscopy

2021 ◽  
Vol 09 (06) ◽  
pp. E918-E924
Author(s):  
Tomonori Yano ◽  
Atsushi Ohata ◽  
Yuji Hiraki ◽  
Makoto Tanaka ◽  
Satoshi Shinozaki ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Porcine Model ◽  
Ex Vivo ◽  
In Vitro Experiments ◽  
Efficacy And Safety ◽  
Coagulative Necrosis ◽  
Novel Technique ◽  
In Vivo Experiments

Abstract Backgrounds and study aims Gel immersion endoscopy is a novel technique to secure the visual field during endoscopy. The aim of this study was to develop a dedicated gel for this technique. Methods To identify appropriate viscoelasticity and electrical conductivity, various gels were examined. Based on these results, the dedicated gel “OPF-203” was developed. Efficacy and safety of OPF-203 were evaluated in a porcine model. Results  In vitro experiments showed that a viscosity of 230 to 1900 mPa·s, loss tangent (tanδ) ≤ 0.6, and hardness of 240 to 540 N/cm2 were suitable. Ex vivo experiments showed electrical conductivity ≤ 220 μS/cm is appropriate. In vivo experiments using gastrointestinal bleeding showed that OPF-203 provided clear visualization compared to water. After electrocoagulation of gastric mucosa in OPF-203, severe coagulative necrosis was not observed in the muscularis but limited to the mucosa. Conclusions OPF-203 is useful for gel immersion endoscopy.

scholarly journals Time Efficiency of Digitally and Conventionally Produced Single-Unit Restorations

2021 ◽  
Vol 9 (6) ◽  
pp. 62
Author(s):  
Sofia Stromeyer ◽  
Daniel Wiedemeier ◽  
Albert Mehl ◽  
Andreas Ender
Keyword(s):  
Single Unit ◽  
Operating Time ◽  
In Vitro Study ◽  
Working Time ◽  
Control Group ◽  
Similar Amount ◽  
Scan Design ◽  
Time Efficiency ◽  
Dental Professional

The purpose of this in vitro study was to compare the time efficiency of digital chairside and labside workflows with a conventional workflow for single-unit restorations. The time efficiency in this specific sense was defined as the time, which has to be spent in a dental office by a dental professional performing the relevant steps. A model with interchangeable teeth on position 36 was created. These teeth were differently prepared, responding to several clinical situations to perform single-unit restorations. Different manufacturing techniques were used: For the digital workflows, CEREC Omnicam (CER) and Trios 3 (TN/TI) were used. The conventional workflow, using a dual-arch tray impression technique, served as the control group. For the labside workflow (_L) and the conventional impression procedure (CO), the time necessary for the impressions and temporary restorations was recorded and served as operating time. The chairside workflow time was divided by the time for the entire workflow (_C) including scan, design, milling and finishing the milled restoration, and in the actual working time (_CW) leaving out the chairside milling of the restoration. Labside workflow time ranged from 9 min 27 s (CER_L) to 12 min 41 s (TI_L). Entire chairside time ranged from 43 min 35 s (CER_C) to 58 min 43 s (TI_C). Pure chairside working time ranged from 15 min 21 s (CER_CW) to 23 min 17 s (TI_CW). Conventional workflow time was 10 min 39 s (CO) on average. The digital labside workflow and the conventional workflow require a similar amount of time. The digital chairside workflow is more time consuming.

scholarly journals Role of SHH in Patterning Human Pluripotent Cells towards Ventral Forebrain Fates

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 914
Author(s):  
Melanie V. Brady ◽  
Flora M. Vaccarino
Keyword(s):  
Stem Cell ◽  
Human Brain ◽  
Human Development ◽  
Disease Modeling ◽  
Model Systems ◽  
Advantages And Disadvantages ◽  
Technical Ability ◽  
Cellular Phenotypes

The complexities of human neurodevelopment have historically been challenging to decipher but continue to be of great interest in the contexts of healthy neurobiology and disease. The classic animal models and monolayer in vitro systems have limited the types of questions scientists can strive to answer in addition to the technical ability to answer them. However, the tridimensional human stem cell-derived organoid system provides the unique opportunity to model human development and mimic the diverse cellular composition of human organs. This strategy is adaptable and malleable, and these neural organoids possess the morphogenic sensitivity to be patterned in various ways to generate the different regions of the human brain. Furthermore, recapitulating human development provides a platform for disease modeling. One master regulator of human neurodevelopment in many regions of the human brain is sonic hedgehog (SHH), whose expression gradient and pathway activation are responsible for conferring ventral identity and shaping cellular phenotypes throughout the neural axis. This review first discusses the benefits, challenges, and limitations of using organoids for studying human neurodevelopment and disease, comparing advantages and disadvantages with other in vivo and in vitro model systems. Next, we explore the range of control that SHH exhibits on human neurodevelopment, and the application of SHH to various stem cell methodologies, including organoids, to expand our understanding of human development and disease. We outline how this strategy will eventually bring us much closer to uncovering the intricacies of human neurodevelopment and biology.

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