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Cartilage articulation exacerbates chondrocyte damage and death after impact injury

Cornell Affiliated Author(s)

Author

S. Ayala
M.L. Delco
L.A. Fortier
Itai Cohen
L.J. Bonassar

Abstract

Posttraumatic osteoarthritis (PTOA) is typically initiated by momentary supraphysiologic shear and compressive forces delivered to articular cartilage during acute joint injury and develops through subsequent degradation of cartilage matrix components and tissue remodeling. PTOA affects 12% of the population who experience osteoarthritis and is attributed to over $3 billion dollars annually in healthcare costs. It is currently unknown whether articulation of the joint post-injury helps tissue healing or exacerbates cellular dysfunction and eventual death. We hypothesize that post-injury cartilage articulation will lead to increased cartilage damage. Our objective was to test this hypothesis by mimicking the mechanical environment of the joint during and post-injury and determining if subsequent joint articulation exacerbates damage produced by initial injury. We use a model of PTOA that combines impact injury and repetitive sliding with confocal microscopy to quantify and track chondrocyte viability, apoptosis, and mitochondrial depolarization in a depth-dependent manner. Cartilage explants were harvested from neonatal bovine knee joints and subjected to either rapid impact injury (17.34 ± 0.99 MPa, 21.6 ± 2.45 GPa/s), sliding (60 min at 1 mm/s, under 15% axial compression), or rapid impact injury followed by sliding. Explants were then bisected and fluorescently stained for cell viability, caspase activity (apoptosis), and mitochondria polarization. Results show that compared to either impact or sliding alone, explants that were both impacted and slid experienced higher magnitudes of damage spanning greater tissue depths. © 2020 Orthopaedic Research Society. Published by Wiley Periodicals LLC

Date Published

Journal

Journal of Orthopaedic Research

Volume

39

Issue

10

Number of Pages

2130-2140,

URL

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097835655&doi=10.1002%2fjor.24936&partnerID=40&md5=d0f16557489ae35775054ec9f6775056

DOI

10.1002/jor.24936

Research Area

Group (Lab)

Itai Cohen Group

Funding Source

1R03AR075929‐01
5K08AR068470‐02
NSF CMMI‐1536463
CMMI-1536463
DMR‐1807602
S10OD018516
CO29155

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