Comparison of Compressive Stress-Relaxation Behavior in Osteoarthritic (ICRS Graded) Human Articular Cartilage

• Published in: International journal of molecular sciences Vol. 19; no. 2; p. 413
• Main Authors: Kumar, Rajesh, Pierce, David M, Isaksen, Vidar, Davies, Catharina de Lange, Drogset, Jon O, Lilledahl, Magnus B
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31.01.2018; MDPI
• Subjects: Articular cartilage; Biocompatibility; Biomechanical characterization; Biomechanics; Cartilage; Cartilage (articular); Cartilage diseases; Clinical medical disciplines: 750; Compressive properties; Computer applications; Data acquisition; Explants; Geriatrics; Human behavior; Hyaluronic acid; Klinisk medisinske fag: 750; Mathematical models; Mechanical properties; Medical disciplines: 700; Medical technology: 620; Medisinsk teknologi: 620; Medisinske Fag: 700; Modulus of elasticity; Older people; Orthopedic surgery: 784; Ortopedisk kirurgi: 784; Osteoarthritis; Pathogenesis; Polymer dynamics; Polymers; Relaxation time; Stress relaxation; Technology: 500; Teknologi: 500; VDP; articular cartilage; stress-relaxation; polymer dynamics; osteoarthritis; biomechanical characterization
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms19020413

Osteoarthritis (OA) is a common joint disorder found mostly in elderly people. The role of mechanical behavior in the progression of OA is complex and remains unclear. The stress-relaxation behavior of human articular cartilage in clinically defined osteoarthritic stages may have importance in diagnosis and prognosis of OA. In this study we investigated differences in the biomechanical responses among human cartilage of ICRS grades I, II and III using polymer dynamics theory. We collected 24 explants of human articular cartilage (eight each of ICRS grade I, II and III) and acquired stress-relaxation data applying a continuous load on the articular surface of each cartilage explant for 1180 s. We observed a significant decrease in Young's modulus, stress-relaxation time, and stretching exponent in advanced stages of OA (ICRS grade III). The stretch exponential model speculated that significant loss in hyaluronic acid polymer might be the reason for the loss of proteoglycan in advanced OA. This work encourages further biomechanical modelling of osteoarthritic cartilage utilizing these data as input parameters to enhance the fidelity of computational models aimed at revealing how mechanical behaviors play a role in pathogenesis of OA.