title: Finite element analysis of stress and wear characterization in total ankle replacements.
abstract: Total Ankle Arthroplasty is performed in order to reduce the pain and loss of ambulation in patients with various forms of arthritis and trauma. Although replacement devices fail by a number of mechanisms, wear in the polyethylene liner constitutes one of the dominating failure modes. This leads to instability and loosening of the implant. Mechanisms that contribute to wear in the liners are high contact and subsurface stresses that break down the material over time. Therefore, it is important to understand the gait that generates these stresses. Methods to characterize and decrease wear in Ohio Total Ankle Replacements (TARs) have been performed in this research. This research utilizes finite element analysis of Wright State University (WSU) patented TAR models. From the Finite element analysis (FEA) results, mathematical models of contact conditions and wear mechanics were developed. The maximum wear rate values obtained in the study (at 25.598MPa, 3.74mm(3)/year) and maximum surface Mises stress obtained with new optimization model (11.52MPa) seem to be comparable with the maximum wear values obtained in other similar studies. These models were used to determine the best methods for wear characterization and reduction. Furthermore, optimization models were developed based on geometry of the implants. These equations optimize geometry, thus congruency and anatomical simulations for total ankle implants.
authors.affiliation: Department of Biomedical, Industrial and Human Factors Engineering, Wright State University, Dayton, OH 45435, USA.
authors.forename: Bradley
authors.initials: B
authors.lastname: Jay Elliot
authors.affiliation: Department of Biomedical, Industrial and Human Factors Engineering, Wright State University, Dayton, OH 45435, USA.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Gundapaneni
authors.affiliation: Department of Biomedical, Industrial and Human Factors Engineering, Wright State University, Dayton, OH 45435, USA; Department of Orthopedic Surgery, Sports Medicine and Rehabilitation, Miami Valley Hospital, Dayton, OH 45409, USA. Electronic address: tarun.goswami@wright.edu.
authors.forename: Tarun
authors.initials: T
authors.lastname: Goswami
mesh_terms: D058737:Arthroplasty, Replacement, Ankle; D004548:Elasticity; D020342:Finite Element Analysis; D008422:Materials Testing; D020959:Polyethylene; D011475:Prosthesis Failure; D013314:Stress, Mechanical; D014783:Viscosity
chemical_list: D020959:Polyethylene
keywords: Ankle replacement; FEA; Gait; Mises stresses; Wear