Influence of stress rate on water loss, matrix deformation and chondrocyte viability in impacted articular cartilage

2005 ◽  
Vol 38 (3) ◽  
pp. 493-502 ◽  
Author(s):  
Dejan Milentijevic ◽  
Peter A. Torzilli
Keyword(s):  
Articular Cartilage ◽  
Water Loss ◽  
Stress Rate ◽  
Chondrocyte Viability ◽  
Matrix Deformation

Influence of Stress Magnitude on Water Loss and Chondrocyte Viability in Impacted Articular Cartilage

2003 ◽  
Vol 125 (5) ◽  
pp. 594-601 ◽  
Author(s):  
Dejan Milentijevic ◽  
David L. Helfet ◽  
Peter A. Torzilli
Keyword(s):  
Articular Cartilage ◽  
Water Loss ◽  
Articular Surface ◽  
Axial Strain ◽  
Biological Response ◽  
Peak Stress ◽  
Cartilage Explants ◽  
Axial Deformation ◽  
Chondrocyte Viability ◽  
Chondrocyte Death

The objective of this study was to assess mechano-biological response of articular cartilage when subjected to a single impact stress. Mature bovine cartilage explants were impacted with peak stresses ranging from 10 to 60 MPa at a stress rate of 350 MPa/s. Water loss, matrix axial deformation, dynamic impact modulus (DIM), and cell viability were measured immediately after impaction. The water loss through the articular surface (AS) was small and ranged from 1% to 6% with increasing peak stress. The corresponding axial strains ranged from 2.5% to 25%, respectively, while the DIM was 455.9±111.9 MPa. Chondrocyte death started at the articular surface and increased in depth to a maximum of 6% (70 μm) of the cartilage thickness at the highest stress. We found that the volumetric (axial) strain was more than twice the amount of water loss at the highest peak stress. Furthermore, specimens impacted such that the interstitial water was forced through the deep zone (DZ) had less water loss, a higher DIM, and no cell death. These findings appear to be due to matrix compaction in the superficial region causing higher compressive strains to occur at the surface rather than in the deeper zones.

scholarly journals Doxycycline preserves chondrocyte viability and function in human and calf articular cartilage ex vivo

2020 ◽  
Vol 8 (17) ◽  
pp. e14571
Author(s):  
Li Yue ◽  
Brian Vuong ◽  
Hongwei Yao ◽  
Brett D. Owens
Keyword(s):  
Articular Cartilage ◽  
Ex Vivo ◽  
Chondrocyte Viability ◽  
And Function

Laser solder welding of articular cartilage: Tensile strength and chondrocyte viability

2001 ◽  
Vol 28 (5) ◽  
pp. 427-434 ◽  
Author(s):  
B.J. Züger ◽  
B. Ott ◽  
P. Mainil-Varlet ◽  
Th. Schaffner ◽  
J.-F. Clémence ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Articular Cartilage ◽  
Chondrocyte Viability

Quantifying Variations in Collagen Matrix Deformation in Loaded Articular Cartilage

2007 ◽  
Author(s):  
Paul Briant ◽  
Scott Bevill ◽  
Thomas P. Andriacchi
Keyword(s):  
Articular Cartilage ◽  
Cruciate Ligament ◽  
Collagen Matrix ◽  
Local Deformation ◽  
Ligament Injury ◽  
Matrix Deformation ◽  
Cartilage Breakdown ◽  
Anterior Cruciate ◽  
Deformation Patterns ◽  
Insight Into

Mechanical loads have been shown in numerous studies to affect the health of articular cartilage [1]. Regional variations in the local deformation within articular cartilage under both normal and abnormal loading are, however, poorly understood. Understanding these deformation patterns is important, since conditions such as anterior cruciate ligament injury have been suggested to initiate cartilage breakdown by shifting the regions of frequent loading within the joint [2]. Quantifying variations in the deformation behavior of the collagen matrix in cartilage under load will therefore provide insight into the mechanical environment within cartilage and test the feasibility of a kinematic pathway to the initiation of osteoarthritis (OA). The objective of this study was to test the hypothesis that the collagen matrix in two regions of cartilage that normally experience different applied loads will deform differently under the same applied load.

scholarly journals Vitrification of Intact Porcine Femoral Condyle Allografts Using an Optimized Approach

Cartilage ◽  
2020 ◽  
pp. 194760352096707
Author(s):  
Kezhou Wu ◽  
Leila Laouar ◽  
Janet A. W. Elliott ◽  
Nadr M. Jomha
Keyword(s):  
Articular Cartilage ◽  
Femoral Condyle ◽  
Membrane Integrity ◽  
Cartilage Defects ◽  
Chondrocyte Viability ◽  
Cell Membrane Integrity ◽  
A Cell ◽  
Vitrification Solution ◽  
Femoral Condyles ◽  
Osteochondral Allografts

Objective Successful preservation of articular cartilage will increase the availability of osteochondral allografts to treat articular cartilage defects. We compared the effects of 2 methods for storing cartilage tissues using 10-mm diameter osteochondral dowels or femoral condyles at −196°C: (a) storage with a surrounding vitrification solution versus (b) storage without a surrounding vitrification solution. We investigated the effects of 2 additives (chondroitin sulfate and ascorbic acid) for vitrification of articular cartilage. Design Healthy porcine stifle joints ( n = 11) from sexually mature pigs were collected from a slaughterhouse within 6 hours after slaughtering. Dimethyl sulfoxide, ethylene glycol, and propylene glycol were permeated into porcine articular cartilage using an optimized 7-hour 3-step cryoprotectant permeation protocol. Chondrocyte viability was assessed by a cell membrane integrity stain and chondrocyte metabolic function was assessed by alamarBlue assay. Femoral condyles after vitrification were assessed by gross morphology for cartilage fractures. Results There were no differences in the chondrocyte viability (~70%) of 10-mm osteochondral dowels after vitrification with or without the surrounding vitrification solution. Chondrocyte viability in porcine femoral condyles was significantly higher after vitrification without the surrounding vitrification solution (~70%) compared to those with the surrounding vitrification solution (8% to 36%). Moreover, articular cartilage fractures were not seen in femoral condyles vitrified without surrounding vitrification solution compared to fractures seen in condyles with surrounding vitrification solution. Conclusions Vitrification of femoral condyle allografts can be achieved by our optimized approach. Removing the surrounding vitrification solution is advantageous for vitrification outcomes of large size osteochondral allografts.

scholarly journals Nonlabeling and quantitative assessment of chondrocyte viability in articular cartilage with intrinsic nonlinear optical signatures

2020 ◽  
Vol 245 (4) ◽  
pp. 348-359 ◽  
Author(s):  
Yang Li ◽  
Xun Chen ◽  
Beckham Watkins ◽  
Neal Saini ◽  
Steven Gannon ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Second Harmonic Generation ◽  
Cell Viability ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Cartilage Tissue ◽  
Imaging Method ◽  
Chondrocyte Viability ◽  
Two Photon

Chondrocyte viability is a crucial factor for evaluating cartilage health. Most prevalent cell viability assays rely on dyes and are not applicable for in vivo or longitudinal studies. Here we demonstrated that the two-photon excited autofluorescence and second harmonic generation microscopy provided high-resolution imaging of cartilage tissue and distinguished live/dead chondrocytes by visual assessment. Furthermore, the normalized autofluorescence ratio was proposed as a quantitative indicator to determine chondrocyte viability. Based on the indicator, a curve fitting and simulated receiver operating characteristic method was proposed to identify the live/dead cell populations as well as the indicator threshold without dye labeling. Thus, it established the label-free imaging method for chondrocyte viability assay in cartilage tissue. Impact statement Chondrocytes are the only cellular component found in the cartilage, playing a critical role in maintaining the homeostasis of articular cartilage. The viability of chondrocytes is a crucial factor for evaluating cartilage health. However, the current prevalent cell viability assays rely on dye staining and thereby are not applicable in vivo or in longitudinal assessments. In this study, we demonstrate that the intrinsic signals such as two-photon excited autofluorescence and second harmonic generation can be used to classify live and dead chondrocytes in cartilage tissue. A quantitative measure is also proposed allowing development of automated assessment algorithms. The nonlabeling nature of this method suggests the potential applicability to nondestructive and in vivo assessment of cartilage health.

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.

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