The influence of the viscoelastic property of polycarbonate urethane as an artificial disc core material under various physiological motions at the L4–L5 level

Abstract

Intervertebral disc (IVD) degeneration is one of the musculoskeletal disorders due to the Degenerative Disc Disease (DDD), that cause low back pain (LBP) and leads to a reduced range of motion. Spinal fusion and arthroplasty are the other surgical procedures that could replace the disc affected by DDD against artificial disc replacement (ADR). This study aims to analyse the biomechanical behaviour of proposed core material as Polycarbonate Urethane (PCU) in the L4–L5 lumbar segment for ADR with Ti-6Al-4V and Co-28Cr-6M as endplate materials and compare it to the performance of an ultra-high molecular weight polyethylene (UHMWPE) core. Finite element methods have been approached to measure the overall stress distribution along with other physiological motions like Flexion (FLEX), Extension (EXT), Axial rotation (AR) and Lateral bending (LB), respectively. Preload of 450 N compressive load, 8 N-m for Flex, 6 N-m for EXT, 6 N-m for AR and 4 N-m for LB are applied. It could be concluded that Ti-6Al-4V – PCU and Co-28Cr-6M – PCU is the best composition for the ADR for the L4–L5 level.

Nucleus Disc Replacement: Design and Material Selection FEA Analysis

“…We searched extensively to select the material that best simulated the biomechanical behavior of the nucleus pulposus. Silicones were ruled out because they crack and fracture over time [25], and polyurethanes were too rigid [35], but polycarbonate polyurethanes [36] suited our requirements. Terefore, we chose Bionate ® (Polymer Technology Group DSM-PTG, Berkeley, California, USA) [37].…”