Region partitioning of articular cartilage with streaming-potential-based parameters and indentation maps

• Published in: Journal of the mechanical behavior of biomedical materials 2024-06, Vol.154, p.106534-106534, Article 106534
• Main Authors: Hamsayeh Abbasi Niasar, E., Brenneman Wilson, E.C., Quenneville, C.E., Maly, M.R., Li, L.P.
• Format: Article
• Language: English
• Subjects: Animals; Articular cartilage; Cartilage, Articular; Clustering; Femur; Inhomogeneity; Knee Joint; Site-specific material property; Streaming potential; Swine
• ISSN: 1751-6161; 1878-0180
• DOI: 10.1016/j.jmbbm.2024.106534

Articular cartilage exhibits site-specific tissue inhomogeneity, for which the tissue properties may continuously vary across the articular surface. To facilitate practical applications such as studying site-specific cartilage degeneration, the inhomogeneity may be approximated with several distinct region-wise variations, with one set of tissue properties for one region. A clustering method was previously developed to partition such regions using cartilage indentation-relaxation and thickness mapping instead of simply using surface geometry. In the present study, a quantitative parameter based on streaming potential measurement was introduced as an additional feature to assess the applicability of the methodology with independent datasets. Experimental data were collected from 24 sets of femoral condyles, extracted from fresh porcine stifle joints, through streaming potential mapping, automated indentation, and needle penetration tests. K-means clustering and Elbow method were used to find optimal region partitions. Consistent with previous findings, three regions were suggested for either lateral or medial condyle regardless of left or right joint. The region shapes were approximately triangular or trapezoidal, which was similar to what was found previously. Streaming potentials were confirmed to be region-dependent, but not significantly different among joints. The cartilage was significantly thicker in the medial than lateral condyles. The region areas were consistent among joints, and comparable to that found in a previous study. The present study demonstrated the capability of region partitioning methods with different variables, which may facilitate new applications whenever site-specific tissue properties must be considered. [Display omitted] •Introduced a streaming potential-derived parameter in clustering to characterize region-dependent cartilage inhomogeneity.•Partitioned regions of condyle cartilage with streaming potential, indention-relaxation and thickness maps from 24 porcine stifle joints.•Proposed three triangular or trapezoidal regions, as the simplest approximation to model site-specific inhomogeneity across a femoral condyle.•Confirmed region-dependent streaming potential variations over femoral condyles.