The 'instantaneous' compressive modulus of human articular cartilage in joints of the lower limb

Shepherd, Duncan E.T.; Seedhom, B B

doi:10.1093/rheumatology/38.2.124

Cited by 209 publications

(167 citation statements)

References 5 publications

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“…For example, tough living tissues such as tendon (E ¼ 143-2310 MPa), human ligament (E ¼ 65-541 MPa), or cancellous bone (E ¼ 20-500 MPa) 66 have a Young's modulus comparable to the high crosslinking degree samples. In applications where the involved tissue is soer and more elastic, the low crosslinking degree samples could be offered similar mechanical compliance for some human elastic so tissues such as knee articular cartilage (2.1-11.8 MPa), 67,68 cerebral vein (6.85 MPa) and artery (15.6 MPa), aortic valve leaet (15 AE 6 MPa) 59 or pericardium (20.4 AE 1.9 MPa). 69 On the other hand, in the context of biomaterials applications, the design of mechanically stable materials over an extended period is of importance for tissue remodelling at the wound site.…”

Section: 63mentioning

confidence: 99%

Mechanical properties and degradation studies of poly(mannitol sebacate)/cellulose nanocrystals nanocomposites

et al. 2015

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A., 2008, 105, 2307). However, PPS generally display poor mechanical properties, in particular a low modulus, that limit the true potential of these materials in the biomedical field. Here, we introduce an approach to obtain nanocomposites based on poly(mannitol sebacate) (PMS) matrices reinforced with cellulose nanocrystals (CNCs) in order to improve the application range of these materials. Different strategies were used based on varying the feed ratios between mannitol : sebacic acid (1 : 1 and 1 : 2), crosslinking conditions and CNCs content, resulting in different degrees of crosslinking and, therefore, mechanical and degradation behavior. All of the developed nanocomposites displayed the expected mass loss during the degradation studies in simulated body fluid (SBF) similar to the neat matrix, however, doubling the sebacic acid feed ratio or extending the curing temperature and time, resulted in higher mechanical properties, structural integrity, and shape stability during a degradation time lessening mass loss rate. Changing mannitol : sebacic acid reaction ratios from 1 : 1 to 1 : 2 and for low crosslinking degree neat samples, the Young's modulus increases four-fold, while mass loss after 150 days of incubation is reduced by half. The Young's modulus range obtained with this process covers the range of human elastic soft tissues to tough tissues (0.7-200 MPa). IntroductionIn the past few years, there has been steady progress in the development of biodegradable polymers for application in the medical eld because these materials provide new opportunities to design less invasive and resorbable implants, tissue scaffolds, and medical devices that are able to avoid second revision surgeries, that limit the risk of infection and results in less trauma for the patient.5-8 Moreover, biodegradable polymeric systems which offer the possibility to tailor their mechanical properties from so to stiffer as well as the biodegradability ratio by varying the processing conditions also have additional advantages. Medical devices based on different classes of biodegradable polymers such as polyesters, polyanhydrides and polyurethanes have been widely investigated and some of them are commercially available as resorbable sutures, drug delivery systems, vascular gras, wafers and orthopaedic xation devices based, among others, on polylactic acid (PLA), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) (PLGA), poly(3-caprolactone) (PCL), poly(p-dioxanone) (PDO), or poly(trimethylene carbonate) (PTMC).9,10 However, most of these polymeric systems have degradation rates that are not optimal for short-medium term applications. For example, it takes more than 24 months for poly(caprolactones) and poly(Llactic acid) to degrade in a biological environment, and from 2 to 24 months, depending on the ratio, for copolymers of polylactic acid (PLA) and polyglycolic acid (PGA). Also, the degradation rate for polyanhydrides is slow, around 12 months. 6,9,11 Moreover, these polymers have a lack of exibility and elasticity at bod...

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Section: 63mentioning

confidence: 99%

Mechanical properties and degradation studies of poly(mannitol sebacate)/cellulose nanocrystals nanocomposites

et al. 2015

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“…The menisci were therefore modeled as linearly elastic, transversely isotropic materials [1,2,4,9,10,16,25,30,[34][35][36]39,[43][44][45]52], where the modulus and Poisson's ratio were 20 MPa and 0.2, respectively, in the radial and axial directions, and 140 MPa and 0.3, respectively, in the circumferential direction [4,30,45,52]. Time dependent effects of the cartilage and menisci properties were not considered due to the quasi-static nature of the models [4,7,8,23,30,32,35,[40][41][42]48,53,54]. The anterior and posterior meniscal roots for each meniscus were modeled as linear springs with spring constants of 2000 N/mm [9,23,25,30,35,36,45,52].…”

Section: Materials Propertiesmentioning

confidence: 99%

Subject-Specific Finite Element Modeling of the Tibiofemoral Joint Based on CT, Magnetic Resonance Imaging and Dynamic Stereo-Radiography Data in Vivo

Carey

Zheng

Aiyangar

et al. 2014

Journal of Biomechanical Engineering

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In this paper, we present a new methodology for subject-specific finite element modeling of the tibiofemoral joint based on in vivo computed tomography (CT), magnetic resonance imaging (MRI), and dynamic stereo-radiography (DSX) data. We implemented and compared two techniques to incorporate in vivo skeletal kinematics as boundary conditions: one used MRI-measured tibiofemoral kinematics in a nonweight-bearing supine position and allowed five degrees of freedom (excluding flexion-extension) at the joint in response to an axially applied force; the other used DSX-measured tibiofemoral kinematics in a weight-bearing standing position and permitted only axial translation in response to the same force. Verification and comparison of the model predictions employed data from a meniscus transplantation study subject with a meniscectomized and an intact knee. The model-predicted cartilage-cartilage contact areas were examined against "benchmarks" from a novel in situ contact area analysis (ISCAA) in which the intersection volume between nondeformed femoral and tibial cartilage was characterized to determine the contact. The results showed that the DSX-based model predicted contact areas in close alignment with the benchmarks, and outperformed the MRI-based model: the contact centroid predicted by the former was on average 85% closer to the benchmark location. The DSX-based FE model predictions also indicated that the (lateral) meniscectomy increased the contact area in the lateral compartment and increased the maximum contact pressure and maximum compressive stress in both compartments. We discuss the importance of accurate, task-specific skeletal kinematics in subject-specific FE modeling, along with the effects of simplifying assumptions and limitations.

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“…It is well known that articular cartilage exhibits depth and location dependent inhomogeneities in material structure (36)(37)(38), and these factors were not part of our study design. In addition, although similar (25)(26)(27)(28), small differences will exist between x-ray attenuation values of real tissue to that of the materials used in our phantom.…”

Section: Study Limitationsmentioning

confidence: 99%

Cartilage Thickness: Factors Influencing Multidetector CT Measurements in a Phantom Study

Anderson¹,

Ellis²,

Peters³

et al. 2008

Radiology

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PURPOSE-To prospectively assess in a phantom the reconstruction errors and detection limits of cartilage thickness measurements from MDCT arthrography as a function of contrast agent concentration, imaging plane, spatial resolution, joint space and tube current, using known measurements as the reference standard.MATERIALS AND METHODS-A phantom with nine chambers was manufactured. Each chamber had a nylon cylinder encased by sleeves of aluminum and polycarbonate to simulate trabecular bone, cortical bone, and cartilage. Variations in simulated cartilage thickness and joint space were assessed. The phantom was scanned with and without contrast agent on three separate days, with chamber axes both perpendicular and parallel to the scanner axis. Images were reconstructed at intervals of both 1.0 and 0.5 mm. Contrast agent concentration and tube current were varied. Simulated cartilage thickness was determined from image segmentation. Root mean squared and mean residual errors were used to characterize the measurements. CT scanner and image segmentation reproducibility were determined. RESULTS-Simulated cartilage was reconstructed with < 10% error for thicknesses >1.0 mm when no contrast agent or a low concentration of contrast agent (25%) was used. Errors grew as concentration of contrast agent increased. Decreasing the simulated joint space to 0.5 mm caused slight increases in error; below 0.5 mm errors grew substantially. Measurements from anisotropic image data had errors greater than those for isotropic data. Altering tube current did not affect reconstruction errors. CONCLUSION-Our study establishes lower bounds and repeatability of simulated cartilage thickness measurement using MDCT arthrography, and provides data pertinent to choosing contrast agent concentration, joint spacing, scanning plane, and spatial resolution to reduce reconstruction errors.

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The 'instantaneous' compressive modulus of human articular cartilage in joints of the lower limb

Cited by 209 publications

References 5 publications

Mechanical properties and degradation studies of poly(mannitol sebacate)/cellulose nanocrystals nanocomposites

Mechanical properties and degradation studies of poly(mannitol sebacate)/cellulose nanocrystals nanocomposites

Subject-Specific Finite Element Modeling of the Tibiofemoral Joint Based on CT, Magnetic Resonance Imaging and Dynamic Stereo-Radiography Data in Vivo

Cartilage Thickness: Factors Influencing Multidetector CT Measurements in a Phantom Study

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