Design of a free-floating polycarbonate-urethane meniscal implant using finite element modeling and experimental validation.

The development of a synthetic meniscal implant that does not require surgical attachment but still provides the biomechanical function necessary for joint preservation would have important advantages. We present a computational-experimental approach for the design optimization of a free-floating polycarbonate-urethane (PCU) meniscal implant. Validated 3D finite element (FE) models of the knee and PCU-based implant were analyzed under physiological loads. The model was validated by comparing calculated pressures, determined from FE analysis to tibial plateau contact pressures measured in a cadaveric knee in vitro. Several models of the implant, some including embedded reinforcement fibers, were tested. An optimal implant configuration was then selected based on the ability to restore pressure distribution in the knee, manufacturability, and long-term safety. The optimal implant design entailed a PCU meniscus embedded with circumferential reinforcement made of polyethylene fibers. This selected design can be manufactured in various sizes, without risking its integrity under joint loads. Importantly, it produces an optimal pressure distribution, similar in shape and values to that of natural meniscus. We have shown that a fiber-reinforced, free-floating PCU meniscal implant can redistribute joint loads in a similar pattern to natural meniscus, without risking the integrity of the implant materials.

[1]  B Calvo,et al.  Finite element analysis of the effect of meniscal tears and meniscectomies on human knee biomechanics. , 2005, Clinical biomechanics.

[2]  R. Warren,et al.  The effect of lateral meniscectomy on motion of the knee. , 1989, The Journal of bone and joint surgery. American volume.

[3]  M. Hull,et al.  How the stiffness of meniscal attachments and meniscal material properties affect tibio-femoral contact pressure computed using a validated finite element model of the human knee joint. , 2003, Journal of biomechanics.

[4]  R. Aspden,et al.  Collagen orientations in the meniscus of the knee joint. , 1985, Journal of anatomy.

[5]  A. Amis,et al.  The effects of lateral meniscal allograft transplantation techniques on tibio-femoral contact pressures , 2008, Knee Surgery, Sports Traumatology, Arthroscopy.

[6]  J. Carrino,et al.  Medial meniscus extrusion on knee MRI: is extent associated with severity of degeneration or type of tear? , 2004, AJR. American journal of roentgenology.

[7]  A. Amis,et al.  The consequences of meniscectomy. , 2006, The Journal of bone and joint surgery. British volume.

[8]  Masanori Kobayashi,et al.  A two year in vivo study of polyvinyl alcohol-hydrogel (PVA-H) artificial meniscus. , 2005, Biomaterials.

[9]  H. Zahouani,et al.  Tribological behavior of thermoplastic polyurethane elastomers , 2007 .

[10]  P. Bulgheroni,et al.  Follow-up of collagen meniscus implant patients: clinical, radiological, and magnetic resonance imaging results at 5 years. , 2010, The Knee.

[11]  B B Seedhom,et al.  The 'instantaneous' compressive modulus of human articular cartilage in joints of the lower limb. , 1999, Rheumatology.

[12]  P. Buma,et al.  Replacement of the Knee Meniscus by a Porous Polymer Implant , 2006, The American journal of sports medicine.

[13]  M. Englund,et al.  Risk factors for symptomatic knee osteoarthritis fifteen to twenty-two years after meniscectomy. , 2004, Arthritis and rheumatism.

[14]  M. Hull,et al.  The level of compressive load affects conclusions from statistical analyses to determine whether a lateral meniscal autograft restores tibial contact pressure to normal: A study in human cadaveric knees , 2003, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[15]  A V Swan,et al.  Late degenerative changes after meniscectomy. Factors affecting the knee after operation. , 1984, The Journal of bone and joint surgery. British volume.

[16]  F. Guilak,et al.  Joint degeneration following meniscal allograft transplantation in a canine model: mechanical properties and semiquantitative histology of articular cartilage , 2002, Knee Surgery, Sports Traumatology, Arthroscopy.

[17]  H. Potter,et al.  Hydrogel Meniscal Replacement in the Sheep Knee , 2007, The American journal of sports medicine.

[18]  M. Oka,et al.  Preliminary study of polyvinyl alcohol-hydrogel (PVA-H) artificial meniscus. , 2003, Biomaterials.

[19]  Stephen M Howell,et al.  Identification of cross-sectional parameters of lateral meniscal allografts that predict tibial contact pressure in human cadaveric knees. , 2002, Journal of biomechanical engineering.

[20]  F. Noyes,et al.  Meniscal transplantation in symptomatic patients less than fifty years old. , 2005, The Journal of bone and joint surgery. American volume.

[21]  M. Mooney.  A Theory of Large Elastic Deformation , 1940 .

[22]  L. Ambrosio,et al.  A tissue engineering approach to meniscus regeneration in a sheep model. , 2006, Osteoarthritis and cartilage.

[23]  T. Fukubayashi,et al.  Load-bearing mode of the knee joint: physical behavior of the knee joint with or without menisci. , 1980, Clinical orthopaedics and related research.

[24]  Carl Joachim Wirth,et al.  The current state of meniscal allograft transplantation and replacement. , 2003, The Knee.

[25]  A. M. Ahmed,et al.  Tensile stress-strain characteristics of the human meniscal material. , 1995, Journal of biomechanics.

[26]  A. B. Drought,et al.  WALKING PATTERNS OF NORMAL MEN. , 1964, The Journal of bone and joint surgery. American volume.

[27]  F Guilak,et al.  A novel quantitative approach for evaluating contact mechanics of meniscal replacements. , 2010, Journal of biomechanical engineering.

[28]  J B Morrison,et al.  The mechanics of the knee joint in relation to normal walking. , 1970, Journal of biomechanics.

[29]  R. Huiskes,et al.  Development and validation of a three-dimensional finite element model of the pelvic bone. , 1995, Journal of biomechanical engineering.

[30]  A. M. Ahmed,et al.  In-vitro measurement of static pressure distribution in synovial joints--Part I: Tibial surface of the knee. , 1983, Journal of biomechanical engineering.

[31]  E. V. Arkel,et al.  Survival analysis of human meniscal transplantations , 2002 .

[32]  B. Gansbacher,et al.  Second generation of meniscus transplantation: in-vivo study with tissue engineered meniscus replacement , 2006, Archives of Orthopaedic and Trauma Surgery.

[33]  Y. Itzchak,et al.  Assessment of mechanical conditions in sub-dermal tissues during sitting: a combined experimental-MRI and finite element approach. , 2007, Journal of biomechanics.

[34]  M. Hull,et al.  A finite element model of the human knee joint for the study of tibio-femoral contact. , 2002, Journal of biomechanical engineering.

[35]  Cyril B Frank,et al.  Finite element analysis of the meniscus: the influence of geometry and material properties on its behaviour. , 2003, The Knee.

[36]  R. Cameron,et al.  Analysis and evaluation of a biomedical polycarbonate urethane tested in an in vitro study and an ovine arthroplasty model. Part II: in vivo investigation. , 2005, Biomaterials.

[37]  A. Unsworth,et al.  Compliant Layer Acetabular Cups: Friction Testing of a Range of Materials and Designs for a New Generation of Prosthesis that Mimics the Natural Joint , 2006, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[38]  Barbara Zielinska,et al.  3D finite element model of meniscectomy: changes in joint contact behavior. , 2006, Journal of biomechanical engineering.

[39]  K. Milachowski,et al.  Homologous meniscus transplantation , 1989, International Orthopaedics.

[40]  Hamid Nayeb-Hashemi,et al.  Influence of Meniscectomy and Meniscus Replacement on the Stress Distribution in Human Knee Joint , 2008, Annals of Biomedical Engineering.