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

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.

2018 ◽  
Vol 7 (7) ◽  
pp. 457-467 ◽  
Author(s):  
I. D. M. Smith ◽  
K. M. Milto ◽  
C. J. Doherty ◽  
S. G. B. Amyes ◽  
A. H. R. W. Simpson ◽  
...  

ObjectivesStaphylococcus aureus (S. aureus) is the most commonly implicated organism in septic arthritis, a condition that may be highly destructive to articular cartilage. Previous studies investigating laboratory and clinical strains of S. aureus have demonstrated that potent toxins induced significant chondrocyte death, although the precise toxin or toxins that were involved was unknown. In this study, we used isogenic S. aureus mutants to assess the influence of alpha (Hla)-, beta (Hlb)-, and gamma (Hlg)-haemolysins, toxins considered important for the destruction of host tissue, on in situ bovine chondrocyte viability.MethodsBovine cartilage explants were cultured with isogenic S. aureus mutants and/or their culture supernatants. Chondrocyte viability was then assessed within defined regions of interest in the axial and coronal plane following live- and dead-cell imaging using the fluorescent probes 5-chloromethylfluorescein diacetate and propidium iodide, respectively, and confocal laser-scanning microscopy.ResultsHla-producing mutants caused substantial chondrocyte death compared with the toxin-deficient control (Hla-Hlb-Hlg-), whilst mutants producing Hlb and Hlg in the absence of Hla induced minimal chondrocyte death. Coronal studies established that Hla-induced chondrocyte death started in the superficial zone of cartilage and spread to deeper layers, whereas Hlb and Hlg toxins were without significant effect.ConclusionThis study identified Hla as a highly potent S. aureus toxin that caused rapid chondrocyte death in bovine cartilage, with other toxins or metabolic products produced by the bacteria playing a minor role. The identification of Hla in mediating chondrocyte death may assist in the development of therapeutic strategies aimed at reducing the extent of cartilage damage during and after an episode of septic arthritis. Cite this article: I. D. M. Smith, K. M. Milto, C. J. Doherty, S. G. B. Amyes, A. H. R. W. Simpson, A. C. Hall. A potential key role for alpha-haemolysin of Staphylococcus aureus in mediating chondrocyte death in septic arthritis. Bone Joint Res 2018;7:457–467. DOI: 10.1302/2046-3758.77.BJR-2017-0165.R1.


F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 147 ◽  
Author(s):  
Abigail L Clutterbuck ◽  
David Allaway ◽  
Pat Harris ◽  
Ali Mobasheri

Objective: Curcumin (diferuloylmethane) is a phytochemical with potent anti-inflammatory and anti-oxidant properties, and has therapeutic potential for the treatment of a range of inflammatory diseases, including osteoarthritis (OA). The aim of this study was to determine whether non-toxic concentrations of curcumin can reduce interleukin-1beta (IL-1β)-stimulated inflammation and catabolism in an explant model of cartilage inflammation.Methods: Articular cartilage explants and primary chondrocytes were obtained from equine metacarpophalangeal joints. Curcumin was added to monolayer cultured primary chondrocytes and cartilage explants in concentrations ranging from 3μM-100μM. Prostaglandin E2 (PGE2) and matrix metalloproteinase (MMP)-3 release into the secretome of IL-1β-stimulated explants was measured using a competitive ELISA and western blotting respectively. Proteoglycan (PG) release in the secretome was measured using the 1,9-dimethylmethylene blue (DMMB) assay. Cytotoxicity was assessed with a live/dead assay in monolayer cultures after 24 hours, 48 hours and five days, and in explants after five days.Results: Curcumin induced chondrocyte death in primary cultures (50μM p<0.001 and 100μM p<0.001) after 24 hours. After 48 hours and five days, curcumin (≥25μM) significantly increased cell death (p<0.001 both time points). In explants, curcumin toxicity was not observed at concentrations up to and including 25μM after five days. Curcumin (≥3μM) significantly reduced IL-1β-stimulated PG (p<0.05) and PGE2 release (p<0.001) from explants, whilst curcumin (≥12μM) significantly reduced MMP-3 release (p<0.01).Conclusion: Non-cytotoxic concentrations of curcumin exert anti-catabolic and anti-inflammatory effects in cartilage explants.


2017 ◽  
Vol 46 (1) ◽  
pp. 66-71 ◽  
Author(s):  
K. Aaron Shaw ◽  
Colleen Moreland ◽  
Jeremy Jacobs ◽  
Justin M. Hire ◽  
Richard Topolski ◽  
...  

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.


F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 147 ◽  
Author(s):  
Abigail L Clutterbuck ◽  
David Allaway ◽  
Pat Harris ◽  
Ali Mobasheri

Objective: Curcumin (diferuloylmethane) is a phytochemical with potent anti-inflammatory and anti-oxidant properties, and has therapeutic potential for the treatment of a range of inflammatory diseases, including osteoarthritis (OA). The aim of this study was to determine whether non-toxic concentrations of curcumin can reduce interleukin-1beta (IL-1β)-stimulated inflammation and catabolism in an explant model of cartilage inflammation.Methods: Articular cartilage explants and primary chondrocytes were obtained from equine metacarpophalangeal joints. Curcumin was added to monolayer cultured primary chondrocytes and cartilage explants in concentrations ranging from 3μM-100μM. Prostaglandin E2 (PGE2) and matrix metalloproteinase (MMP)-3 release into the secretome of IL-1β-stimulated explants was measured using a competitive ELISA and western blotting respectively. Proteoglycan (PG) release in the secretome was measured using the 1,9-dimethylmethylene blue (DMMB) assay. Cytotoxicity was assessed with a live/dead assay in monolayer cultures after 24 hours, 48 hours and five days, and in explants after five days.Results: Curcumin induced chondrocyte death in primary cultures (50μM p<0.001 and 100μM p<0.001) after 24 hours. After 48 hours and five days, curcumin (≥25μM) significantly increased cell death (p<0.001 both time points). In explants, curcumin toxicity was not observed at concentrations up to and including 25μM after five days. Curcumin (≥3μM) significantly reduced IL-1β-stimulated PG (p<0.05) and PGE2 release (p<0.001) from explants, whilst curcumin (≥12μM) significantly reduced MMP-3 release (p<0.01).Conclusion: Non-cytotoxic concentrations of curcumin exert anti-catabolic and anti-inflammatory effects in cartilage explants.


2007 ◽  
Vol 20 (01) ◽  
pp. 34-37 ◽  
Author(s):  
M. L. Meyer ◽  
J. J Bogdanske ◽  
M. D. Markel ◽  
Y. Lu

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.


Cartilage ◽  
2020 ◽  
pp. 194760352090475
Author(s):  
Klemen Ravnihar ◽  
Tomaž Marš ◽  
Sergej Pirkmajer ◽  
Armin Alibegović ◽  
Gordana Koželj ◽  
...  

Objective To evaluate the in vivo effect of a single intra-articular injection of local anesthetic (LA) lidocaine on the viability of articular cartilage in the intact or osteoarthritic (OA) human knees, and to measure the synovial postinjection concentration of lidocaine in the knee Design This study includes 3 interconnected experiments: (A) Synovial LA concentration measurement after a 2% lidocaine injection before knee arthroscopy in 10 patients by liquid chromatography–tandem mass spectrometry (LC-MS/MS). (B) Human osteochondral explants ( N = 27) from intact knees procured at autopsies were incubated for different time intervals (30 minutes, 2 hours, 24 hours) with 2% lidocaine, 0.04% lidocaine (measured), or culture medium (control), and later evaluated for cell viability by LIVE/DEAD staining. (C) Ten out of 19 matched patients scheduled for knee replacement received a single intra-articular injection of 2% lidocaine approximately 30 minutes prior to the procedure; 9 patients served as control. Osteochondral samples with OA changes were harvested during surgery and analyzed for chondrocyte viability by LIVE/DEAD staining. Results (A) The synovial LA concentration was significantly lower than the primary concentration injected: average 0.23 mg/mL (0.02%), highest measured 0.37 mg/mL (0.04%). (B) In vitro exposure to a reduced LA concentration had no significant influence on chondrocyte viability in intact cartilage explants (24-hour averages: control, 93%; 0.04% lidocaine, 92%; 2% lidocaine, 79%). (C) Viability of chondrocytes in OA knees was similar between 2% lidocaine injection (85%) and control (80%). Conclusions A single intra-articular knee injection of 2% lidocaine did not influence the chondrocyte viability neither in healthy nor in OA cartilage. A fast postinjection reduction of synovial LA concentration (more than 40 times) is the most likely protective mechanism.


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