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acetabulum, which with a modern porous coating, failure may have been avoided or delayed.Despite high inclinations angles no soft tissue reactions were identified within this series. Nofemoral failures were identified suggesting unlike much literature focus, long-term failure maynot be related to the femoral head or neck.Saturday, October 9, 2010, 10:20-11:05Session A19: Miscellaneous ArthroplastyBiomechanical Behavior Between Prodisc-L and Physio-L in Total DiscReplacement*Cheng-Chan Lo - National Chiao Tung University - Hsinchu, TaiwanKai-Jow Tsai - Cathay General Hospital - Taipei, TaiwanZheng-Cheng Zhong - National Yang Ming University - Taipei, TaiwanChinghua Hung - National Chiao Tung University - Hsinchu, Taiwan*Email: 288061108@yahoo.com.twThe emerging of non-fusion surgery is aimed to solve the long-term complication of fusionsurgery that may bring the adjacent disc degeneration. Among several kinds of artificial discsdeveloped in these years, the majority in the market is Prodisc-L (Synthes Inc.) which isdesigned with the purpose to restore the motions including anteroposterior translation, lateralbending, and axial rotation. These is also one artificial disc called Physio-L (Nexgen Spine)which were hyper-elastic material (Polycarbonate Polyurethanes) and is designed to restore themotions maintioned above plus axial loading. The concept of using hyper-elastic material asdisc is to mimic the material properties of intervetebral discs so that this disc both absorb theaxial loading and also restore the physiological range of motion. Few studies focused on thebiomechanical behavior of hyper-elastic artificial discs have yet been reported. Therefore, thepurpose of this study is to compare the biomechanical behavior between Prodisc-L and Physio-L.A validated three-dimensional finite element model of the L1-L5 lumbar intact spine was usedin this study with ANSYS software [Fig.1]. Total disc replacement surgery, partial discectomy,total nuclectomy and removal of the anterior longitudinal ligament were performed at the L3/L4segment of this intact model, and the Prodisc-L and Physio-L was implanted into L3/L4segment, respectively. In addition, hyper-elastic materials adopted by Physio-L are usuallycategorized by their hardness into soft and hard [Fig.2]. Therefore, two kinds of Physio-L werestudied. A 400 N follower load and a 10 N-m moment were applied to the intact model toobtain four physiological motions as comparison baseline. The implanted models weresubjected to 400 N follower load and specific moments in accordance with the hybrid testmethod.For the Prodisc-L model in the surgical segment, the range of motion (ROM) varied by -26%,+17%, -0.01%, and -0.04% in flexion, extension, lateral bending, and axial rotation,respectively, as compared to intact model [Fig.3]. For the Physio-L (soft) model, ROM variedby +10%, +8%, +3%, and +19% in four physiological motions, respectively. For the physio-L(hard) model, ROM varied by +1%, +8%, +1%, and +11% in four physiological motions,respectively. For the Prodisc-L model in the adjacent segments, ROM varied by +4% ~ +10%, -file:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]