Conducting Polymer Coatings for Bioelectronic Arthroscopy Probes.

This study presents conducting polymer coatings as an effective strategy to enhance the performance of electromechanical arthroscopy probes by significantly reducing electrical equilibration time (the period a surgeon must wait for the probe signal to stabilize before measurement) and improving signal stability. Microelectrodes coated with poly(3,4-ethylenedioxythiophene, PEDOT) reach electrical equilibrium in physiological medium within 10 s, compared to over 2 min for standard electroless nickel immersion gold-based (ENIG) probes and ≈20 s for electrodeposited gold, thereby eliminating impractical delays during arthroscopic procedures. PEDOT coatings also reduce impedance by two to three orders of magnitude at low frequencies (<1 kHz), minimizing sensitivity to hand motion and reducing the likelihood of repeated measurements.

Non-invasive electroarthrography measures cartilage in live horses and correlates to direct measurements of cartilage streaming potentials in weight bearing regions of equine metacarpophalangeal joints.

Objective: To perform non-invasive Electroarthrography (EAG) on live horses and establish relationships between EAG and direct measurements of cartilage streaming potentials in weight bearing areas of the equine metacarpophalangeal joint.

Design: EAG was performed bilaterally on the metacarpophalangeal joints of live horses (n = 3). Separate experiments used metacarpophalangeal joint explants (n = 11) to measure EAG obtained during simulated loading followed by direct measurements of cartilage streaming potentials on joint surfaces using the Arthro-BST probe.

In vivo biochemical assessment of cartilage with gagCEST MRI: Correlation with cartilage properties.

To assess articular cartilage in vivo, a noninvasive measurement is proposed to evaluate damage of the cartilage. It is hypothesized that glycosaminoglycan chemical exchange saturation transfer (gagCEST) can be applied as a noninvasive imaging technique as it would relate to electromechanical indentation and GAG content as measured with biochemical assays. This pilot study applies gagCEST MRI in total knee arthroplasty (TKA) patients to assess substantially damaged articular cartilage.

Non-invasive Electroarthrography Measures Load-Induced Cartilage Streaming Potentials via Electrodes Placed on Skin Surrounding an Articular Joint.

Objective: We aimed to demonstrate that electroarthrography (EAG) measures streaming potentials originating in the cartilage extracellular matrix during load bearing through electrodes adhered to skin surrounding an articular joint.

Design: Equine metacarpophalangeal joints were subjected to simulated physiological loads while (1) replacing synovial fluid with immersion buffers of different electrolyte concentrations and (2) directly degrading cartilage with trypsin.

Results: An inverse relationship between ionic strength and EAG coefficient was detected.

Development of an Electromechanical Grade to Assess Human Knee Articular Cartilage Quality.

Quantitative assessments of articular cartilage function are needed to aid clinical decision making. Our objectives were to develop a new electromechanical grade to assess quantitatively cartilage quality and test its reliability. Electromechanical properties were measured using a hand-held electromechanical probe on 200 human articular surfaces from cadaveric donors and osteoarthritic patients.

Electrical potentials measured on the surface of the knee reflect the changes of the contact force in the knee joint produced by postural sway.

Electroarthrography (EAG) is a novel technique for recording potentials on the knee surface that are generated by the compression of articular cartilage and that reflect both compression force and cartilage quality. The mechanical loading of the knee is achieved by transferring the subject's body weight from a bipedal stance to a unipedal stance. We hypothesized that EAG potentials change with postural sway.

Decrease of the electrical potentials measured on the surface of the knee and produced by cartilage compression during successive loading cycles.

Electroarthrography (EAG) is a new technique for measuring electrical potentials appearing on the knee surface during loading that reflects cartilage quality and joint contact force. Our objective was to investigate the evolution of EAG signals during successive loading cycles. The study was conducted on 20 standing subjects who shifted their body weight to achieve knee loading.

Bilayer Implants: Electromechanical Assessment of Regenerated Articular Cartilage in a Sheep Model.

Objective: To compare the regenerative capacity of 2 distinct bilayer implants for the restoration of osteochondral defects in a preliminary sheep model.

Methods: Critical sized osteochondral defects were treated with a novel biomimetic poly-ε-caprolactone (PCL) implant (Treatment No. 2; n = 6) or a combination of Chondro-Gide and Orthoss (Treatment No.

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

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.

Fabrication and characterization of nonplanar microelectrode array circuits for use in arthroscopic diagnosis of cartilage diseases.

A process to fabricate nonplanar microelectrode array circuits was developed and the microelectrodes were characterized. These platinum microelectrode arrays are for recording streaming potential signals generated during indentation of articular cartilage. The nonplanar substrate was produced by permanent deformation of a 7-in-diameter circular stainless-steel wafer to form 32 semi-spherical caps (radius of curvature = 4.