Electromechanical probe and automated indentation maps are sensitive techniques in assessing early degenerated human articular cartilage

Abstract

Recent advances in the development of new drugs to halt or even reverse the progression of Osteoarthritis at an early-stage requires new tools to detect early degeneration of articular cartilage. We investigated the ability of an electromechanical probe and an automated indentation technique to characterize entire human articular surfaces for rapid non-destructive discrimination between early degenerated and healthy articular cartilage. Human cadaveric asymptomatic articular surfaces (four pairs of distal femurs and four pairs of tibial plateaus) were used. They were assessed ex vivo: macroscopically, electromechanically, (maps of the electromechanical quantitative parameter, QP, reflecting streaming potentials), mechanically (maps of the instantaneous modulus, IM), and through cartilage thickness. Osteochondral cores were also harvested from healthy and degenerated regions for histological assessment, biochemical analyses, and unconfined compression tests. The macroscopic visual assessment delimited three distinct regions on each articular surface: Region I was macroscopically degenerated, region II was macroscopically normal but adjacent to regions I and III was the remaining normal articular surface. Thus, each extracted core was assigned to one of the three regions. A mixed effect model revealed that only the QP (p < 0.0001) and IM (p < 0.0001) were able to statistically discriminate the three regions. Effect size was higher for QP and IM than other assessments, indicating greater sensitivity to distinguish early degeneration of cartilage. When considering the mapping feature of the QP and IM techniques, it also revealed bilateral symmetry in a moderately similar distribution pattern between bilateral joints. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:858-867, 2017.

Electromechanical properties of human osteoarthritic and asymptomatic articular cartilage are sensitive and early detectors of degeneration

“…Cartilage electromechanical properties were measured using a hand-held probe (Benchtop Arthro-BST, Biomomentum) 19,25,27,28 . This device allows a non-destructive measurement of streaming potentials generated during a light indentation (~1 s) of the articular cartilage with an array of 37 gold microelectrodes lying on a semi-spherical indenter (Ø ¼ 6.35 mm, 5 microelectrodes/mm 2 ).…”

“…After the electromechanical mapping, the automated thickness mapping was performed using a needle probe (PrecisionGlide intradermal bevel needle 26G 3/8", BD, United States) secured under a load cell on the vertical axis of a multiaxial mechanical tester (Mach-1 v500css, Biomomentum). Cartilage thickness was mapped at the same positions as electromechanical measurement, according to the needle technique adapted from Jurvelin et al 29 and described by Sim et al 25 . The mechanical tester vertically lowers the needle at a constant speed toward the articular surface penetrating the cartilage surface and reaching a predefined maximal load for which it stops inside the bone.…”

“…This stress participates in increasing cartilage hydrostatic pressure, which has been shown to be directly proportional to the streaming potentials 26 . Moreover, this device is nearing clinical application since it offers a specific and sensitive electromechanical parameter called the quantitative parameter (QP) reflecting cartilage integrity 25,27 . To date, however, investigations on both cartilage and subchondral-bone in early progression of human OA remain limited.…”

Automated Indentation Mapping of Vocal Fold Structure and Cover Properties Across Species

“…To overcome limitations of traditional microindentation testing for biologic tissues, we employed an indentation system capable of collecting indentation mapping data across irregularly shaped surfaces to improve existing mechanical testing approaches for laryngeal tissues. This technique successfully measured mechanical properties of irregular geometric surfaces such as articular cartilage . For the purpose of this investigation and to collect valuable normative data, we chose to compare intact, excised hemilarynges from three common animal laryngeal models: swine, leporine, and canine.…”

“…This technique successfully measured mechanical properties of irregular geometric surfaces such as articular cartilage. 9,10 For the purpose of this investigation and to collect valuable normative data, we chose to compare intact, excised hemilarynges from three common animal laryngeal models: swine, leporine, and canine.…”