The effects of radiofrequency energy probe speed and application force on chondrocyte viability

2007 ◽  
Vol 20 (01) ◽  
pp. 34-37 ◽  
Author(s):  
M. L. Meyer ◽  
J. J Bogdanske ◽  
M. D. Markel ◽  
Y. Lu
Keyword(s):  
Articular Cartilage ◽  
In Vitro Study ◽  
Confocal Laser ◽  
Radiofrequency Energy ◽  
Chondrocyte Viability ◽  
Bovine Articular Cartilage ◽  
Cell Staining ◽  
Chondrocyte Death ◽  
Improper Use

Summary Objective: To determine the thermal effects of monopolar radiofrequency energy (mRFE) on bovine articular cartilage when it was moved at different speeds and using varying application forces. Methods: Thirty-six fresh osteochondral sections divided into two groups (18 sections/group) were used in this study. The first group was tested at three speed rates of mRFE probe (1 mm/sec, 5 mm/sec and 10 mm/sec) at a constant force (50 g) applied to the probe tip. In the second group, three application forces of the probe tip were tested (25 g, 50 g and 75 g) at a constant speed (5 mm/sec) (n=6/test). All tests were performed using a custom-built jig to control the mRFE (Vulcan EAS™) probe during a 20-mm pass on each section. After treatment, viability of osteochondral sections was determined by confocal laser microscopy (CLM) combined with vital cell staining. Results: There were not any significant differences in cartilage thickness of tested osteochondral sections among the different speeds or forces. During the mRFE probe treatments at different speeds, CLM demonstrated that probe application at the speed of 1 mm/ sec caused significantly greater chondrocyte death than at the speeds of 5 and 10 mm/sec, whereas there were no significant differences in chondrocyte death among the variable application forces (p>0.05). Discussion: This in vitro study demonstrated that RFE thermal penetration correlated most closely with probe application speed than application force for this mRFE probe. Clinical relevance: Improper use of mRFE may cause thermal injury on articular cartilage.

Lavage Solution Temperature Influences Depth of Chondrocyte Death and Surface Contouring during Thermal Chondroplasty with Temperature-Controlled Monopolar Radiofrequency Energy

2002 ◽  
Vol 30 (5) ◽  
pp. 667-673 ◽  
Author(s):  
Yan Lu ◽  
Ryland B. Edwards ◽  
Shane Nho ◽  
Brian J. Cole ◽  
Mark D. Markel
Keyword(s):  
Treatment Time ◽  
Solution Temperature ◽  
Confocal Laser ◽  
Radiofrequency Energy ◽  
Cartilage Surface ◽  
Chondrocyte Viability ◽  
Chondrocyte Death ◽  
Articular Cartilage Surface ◽  
Thermal Chondroplasty ◽  
Lavage Solution

Background: Although radiofrequency energy can smooth and contour cartilage surface, it has deleterious effects on chondrocyte viability. Hypothesis: Monopolar thermal chondroplasty in a 37°C lavage solution, as compared with a 22° lavage solution, will reduce chondrocyte death and result in greater smoothing of the articular cartilage surface. Study Design: Controlled laboratory study. Methods: Sixteen chondromalacic samples from patients undergoing total knee arthroplasty were divided into two groups: 22°C and 37°C lavage solution. Each sample was divided into two equal parts and half of each group was treated for 10 seconds and the other half for 15 seconds. Results: Confocal laser microscopy demonstrated that the depth of chondrocyte death in the 37°C lavage solution group was significantly less (range, 200 to 340 μm) than that in the 22°C solution group for both 10- and 15-second treatment times. Scanning electron microscopy demonstrated that the cartilage surface in the 37°C lavage solution group was smoother than that in the 22°C solution group for the 10-second treatment time. Energy delivery power in the 37°C lavage solution group was significantly lower than in the 22°C solution group for both treatment times. Conclusions: Thermal chondroplasty with 37°C lavage solution resulted in less depth of chondrocyte death and produced smoother surfaces than with 22°C solution for 10 seconds of treatment. Clinical Relevance: Less chondrocyte death would permit increased use of thermal chondroplasty.

Improved Chondrotoxic Profile of Liposomal Bupivacaine Compared With Standard Bupivacaine After Intra-articular Infiltration in a Porcine Model

2017 ◽  
Vol 46 (1) ◽  
pp. 66-71 ◽  
Author(s):  
K. Aaron Shaw ◽  
Colleen Moreland ◽  
Jeremy Jacobs ◽  
Justin M. Hire ◽  
Richard Topolski ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Articular Chondrocytes ◽  
Management Strategies ◽  
Histologic Examination ◽  
Chondrocyte Viability ◽  
Liposomal Bupivacaine ◽  
Stifle Joint ◽  
Chondrocyte Death

Background: Increasingly, liposomal bupivacaine is being used with multimodal pain management strategies. In vitro investigations have shown decreased chondrotoxicity profiles for liposomal bupivacaine; however, there is no evidence regarding its in vivo effects. Hypothesis/Purpose: This study sought to investigate the in vivo chondrotoxicity of liposomal bupivacaine, hypothesizing that there would be increased chondrocyte viability after exposure to liposomal bupivacaine when compared with standard bupivacaine. Study Design: Controlled laboratory study. Methods: Eight juvenile, female Yorkshire cross piglets underwent a lateral stifle joint injection with either 1.3% liposomal bupivacaine or 0.5% bupivacaine. Injections were performed on one joint per animal with no injection to the contralateral knee, which served as the control. Chondrocyte viability was assessed 1 week after injection with a live-dead staining protocol and histologic examination. Results: Significant chondrocyte death was seen with the live-dead staining in the bupivacaine group (33% nonviable cells) in comparison with liposomal bupivacaine (6.2%) and control (5.8%) groups ( P < .01). However, histologic examination showed no differences in chondral surface integrity, fibrillation, and chondrocyte viability. Conclusion: Liposomal bupivacaine was found to be safe for intra-articular injection in this animal model. Although bupivacaine demonstrated decreased chondrocyte viability on a cellular level, histologically there were no changes. This study highlights the dichotomy between fluorescent staining and histologic appearance of articular chondrocytes in short-term analyses of viability. Clinical Relevance: This study supports the peri-articular application of liposomal bupivacaine in the setting of preserved articular cartilage. A single injection of standard bupivacaine did not produce histologic changes in the articular cartilage.

Changes to articular cartilage following remote application of radiofrequency energy and with or without Cosequin therapy

2009 ◽  
Vol 22 (02) ◽  
pp. 103-112 ◽  
Author(s):  
R. M. McLaughlin ◽  
S. H. Elder ◽  
R. R. Pool ◽  
R. R. Read ◽  
C. R. Boyle ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Metabolic Activity ◽  
Biomechanical Properties ◽  
Compressive Modulus ◽  
Infrapatellar Fat Pad ◽  
Confocal Laser ◽  
Radiofrequency Energy ◽  
Stifle Joint ◽  
Chondrocyte Death ◽  
Significant Difference

Summary Objective: To determine the short- and long-term changes in the biomechanical properties and metabolic activity of articular cartilage following the remote application of bipolar radiofrequency (bRF) and monopolar radiofrequency (mRF) energy within the rabbit stifle joint. Methods: The rabbits were randomly assigned to either Group-1 (normal rabbit food), or they were assigned to Group-2 (2% Cosequin® in the diet). Each rabbit underwent bilateral stifle arthroscopy with either bRF or mRF applied to the infrapatellar fat pad for 45 seconds. Cartilage samples were collected at zero, four, and 14 weeks after surgery. Data were analyzed with a mixed model analysis of variance (ANOVA) for chondrocyte death, amount of GAG synthesis, and the equilibrium compressive modulus. Results: A significant increase in histological damage was noted at weeks four and 14 compared to week zero. Most of the chondrocyte death noted with confocal laser microscopy (49 of 56 samples) was noted in the superficial region (outer 25%) of the articular cartilage. GAG synthesis was not significantly different between groups or devices at any time point. A significant difference was not noted in equilibrium compressive modulus throughout the study. Conclusions: Remote application of bRF and mRF energy lead to immediate chondrocyte death. Most of the damage was superficial hence the metabolic activity and biomechanical properties of the extra-cellular matrix were maintained throughout this study. Treatment with Cosequin did not prevent superficial chondrocyte death caused by the application of radio-frequency (RF) energy with in the joint.

The Time-dependent Effects of Bipolar Radiofrequency Energy on Bovine Articular Cartilage

2020 ◽  
Author(s):  
Liangquan Peng ◽  
Yusheng Li ◽  
Kai Zhang ◽  
Qi Chen ◽  
Lulu Xiao ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Exposure Time ◽  
Treatment Time ◽  
Cartilage Lesion ◽  
Radiofrequency Energy ◽  
Cartilage Surface ◽  
Bovine Articular Cartilage ◽  
Bipolar Radiofrequency ◽  
Articular Cartilage Injury

Abstract Purpose: The purpose of this study was to compare the effect of bipolar radiofrequency energy (bRFE) on chondroplasty at the different time durations in an in vitro experiment that simulated an arthroscopic procedure. Methods: Six fresh bovine knees were used in our study. Six squares were marked on both the medical and lateral femoral condyles of each femur. Each square was respectively treated with bRFE for 0s, 10s, 20s, 30s, 40s and 50s. Full-thickness articular cartilage specimens were harvested from the treatment areas. Each specimen was divided into three distinct parts: one for hematoxylin/eosin staining histology, another for cartilage surface contouring assessment via scanning electron microscopy (SEM), and the last one for glycosaminoglycan (GAG) content measurement. Results: bRFE caused time-correlated damage to chondrocytes, and GAG content in the cartilage was negatively correlated to exposure time. bRFE caused time-correlated damage to chondrocytes. The GAG content in the cartilage negatively correlated with the exposure time. The sealing effect positively correlated with the exposure time. Additionally, it took at least 20 seconds of radiofrequency exposure to render a smooth cartilage surface and a score of 2 (normal) in the scoring system used. Conclusion: bRFE usage in chondroplasty could effectively trim and polish the cartilage lesion area; however, it induces a dose-dependent detrimental effect on chondrocytes and metabolic activity that negatively correlated with the treatment time. Therefore, cautions should be taken in the use of bRFE for treatment of articular cartilage injury.

Quantitative articular cartilage sub-surface defect assessment using optical coherence tomography: An in-vitro study

2019 ◽  
Vol 221 ◽  
pp. 125-134 ◽  
Author(s):  
Roman Michalik ◽  
Thorn Pauer ◽  
Nicolai Brill ◽  
Matthias Knobe ◽  
Markus Tingart ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Articular Cartilage ◽  
Surface Defect ◽  
In Vitro Study ◽  
Vitro Study ◽  
Optical Coherence ◽  
Defect Assessment

scholarly journals Cytotoxic responses of human chondrocytes to bupivacaine, levobupivacaine, and ropivacaine

2019 ◽  
Vol 12 (4) ◽  
pp. 169-178
Author(s):  
Pudkrong Kaewpichit ◽  
Somrat Charuluxananan ◽  
Monpichar Srisa-Art ◽  
Sarocha Sisawat ◽  
Vitavat Aksornkitti ◽  
...  
Keyword(s):  
Colorimetric Assay ◽  
Control Cell ◽  
Human Chondrocytes ◽  
No Production ◽  
Chondrocyte Viability ◽  
Chondrocyte Death ◽  
Phosphate Buffered Saline ◽  
Cytotoxic Responses ◽  
Dependent Pathway

AbstractBackgroundIntra-articular injections of local anesthetics are used commonly in articular surgery. However, chondrocyte viability and metabolism may be adversely affected by various anesthetics.ObjectivesTo assess the chondrotoxic effects of bupivacaine, levobupivacaine, and ropivacaine on human chondrocytes and elucidate possible mechanisms of chondrocyte death.MethodsCultured human chondrocytes (CHON-001) were exposed to 0.25% or 0.5% of bupivacaine, levobupivacaine, and ropivacaine in vitro. Cell viability was determined by flow cytometry after 15, 30, 60, and 120 min of exposure. Chondrocyte reactive oxygen species (ROS) production was measured every 10 min for up to 1 h using 2ʹ,7ʹ-dichlorodihydrofluorescein staining. Chondrocyte production of glycosaminoglycan was measured by capillary electrophoresis. NO production was measured using a colorimetric assay kit.ResultsWe found a significant increase in chondrotoxicity dependent on exposure time and concentration of the anesthetic. At 60 min, chondrocyte viability was significantly (P < 0.05) decreased when exposed to 0.5% levobupivacaine (32.5%), or 0.25% or 0.5% bupivacaine (34.3% or 46.5%, respectively) compared with exposure to phosphate-buffered saline (PBS) vehicle as a control. Cell death at 120 min was mainly necrosis. There was no difference in viability after treatment with either concentration (0.25% or 0.5%) of ropivacaine at any time compared with exposure to PBS. We found increased production of NO, while ROS decreased after exposure to any of the anesthetics tested.ConclusionsRopivacaine may be safer than bupivacaine or levobupivacaine as an intra-articular analgesic. Chondrotoxicity of anesthetics in vitro may be mediated via a reactive nitrogen species-dependent pathway.

Force and vibration analysis in biomechanical preparation of root canals using reciprocating endodontic file system: In vitro study

2021 ◽  
pp. 095441192110442
Author(s):  
Vinod Singh Thakur ◽  
Pavan Kumar Kankar ◽  
Anand Parey ◽  
Arpit Jain ◽  
Prashant Kumar Jain
Keyword(s):  
Root Canal ◽  
Vibration Analysis ◽  
File System ◽  
In Vitro Study ◽  
Root Canal Preparation ◽  
Root Canals ◽  
Improper Use ◽  
Four Levels ◽  
Root Canal Instrumentation

The shaping and cleaning of the root canal are very important in root canal treatment. The excessive force and vibration during biomechanical preparation of the root canal may result in failure of the endodontic file. In this study, force and vibration analysis was carried out during root canal preparation. The samples of human extracted (premolar) teeth were provided by the College of Dental Science and Hospital. Endodontic instruments for reciprocating motion, such as the WaveOne Gold file system, had been used for root canal preparation. Force and vibration signals were recorded by dynamometer and accelerometer, respectively. The acquired signals were denoised using the db4 (SWT denoising 1-D) wavelet. Four levels of decomposition were carried out for each signal. The signal denoising technique was used to remove unwanted noise from the acquired signal. FESEM analysis was used to visualize the levels of severity of endodontic files during the cleaning and shaping of the root canal. In most of the cases, the failure occurred due to the improper use of the root canal instrumentation. The optimum amount of force was used to avoid the file failure and provided the proper instrumentation. The curve fitting regression model was used to find the interdependency between force and vibration.

Endotracheal tubes coated with a broad-spectrum antibacterial ceragenin reduce bacterial biofilm in an in vitro bench top model

2021 ◽  
Author(s):  
María Consuelo Latorre ◽  
María Jesús Pérez-Granda ◽  
Paul B Savage ◽  
Beatriz Alonso ◽  
Pablo Martín-Rabadán ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
In Vitro Study ◽  
Bacterial Biofilm ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Endotracheal Tubes ◽  
Clinical Strains ◽  
Number Of Cells

Abstract Background Ventilator-associated pneumonia is one of the most common nosocomial infections, caused mainly by bacterial/fungal biofilm. Therefore, it is necessary to develop preventive strategies to avoid biofilm formation based on new compounds. Objectives We performed an in vitro study to compare the efficacy of endotracheal tubes (ETTs) coated with the ceragenin CSA-131 and that of uncoated ETTs against the biofilm of clinical strains of Pseudomonas aeruginosa (PA), Escherichia coli (EC) and Staphylococcus aureus (SA). Methods We applied an in vitro bench top model using coated and uncoated ETTs that were treated with three different clinical strains of PA, EC and SA for 5 days. After exposure to biofilm, ETTs were analysed for cfu count by culture of sonicate and total number of cells by confocal laser scanning microscopy. Results The median (IQR) cfu/mL counts of PA, EC and SA in coated and uncoated ETTs were, respectively, as follows: 1.00 × 101 (0.0–3.3 × 102) versus 3.32 × 109 (6.6 × 108–3.8 × 109), P &lt; 0.001; 0.0 (0.0–5.4 × 103) versus 1.32 × 106 (2.3 × 103–5.0 × 107), P &lt; 0.001; and 8.1 × 105 (8.5 × 101–1.4 × 109) versus 2.7 × 108 (8.6 × 106–1.6 × 1011), P = 0.058. The median (IQR) total number of cells of PA, EC and SA in coated and non-coated ETTs were, respectively, as follows: 11.0 [5.5–not applicable (NA)] versus 87.9 (60.5–NA), P = 0.05; 9.1 (6.7–NA) versus 62.6 (42.0–NA), P = 0.05; and 97.7 (94.6–NA) versus 187.3 (43.9–NA), P = 0.827. Conclusions We demonstrated significantly reduced biofilm formation in coated ETTs. However, the difference for SA was not statistically significant. Future clinical studies are needed to support our findings.

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