S M Kurtz

Summary

Affiliation: Exponent Inc
Country: USA

Publications

  1. doi request reprint Advances in zirconia toughened alumina biomaterials for total joint replacement
    Steven M Kurtz
    Exponent, Inc, Philadelphia, PA, United States Drexel University, Philadelphia, PA, United States Electronic address
    J Mech Behav Biomed Mater 31:107-16. 2014
  2. doi request reprint Infection risk for primary and revision instrumented lumbar spine fusion in the Medicare population
    Steven M Kurtz
    Exponent, Inc, Philadelphia, Pennsylvania 19104, USA
    J Neurosurg Spine 17:342-7. 2012
  3. doi request reprint Accelerated aqueous aging simulation of in vivo oxidation for gamma-sterilized UHMWPE
    Steven M Kurtz
    Exponent, Inc, Philadelphia, Pennsylvania, USA
    J Biomed Mater Res B Appl Biomater 90:368-72. 2009
  4. ncbi request reprint Static and fatigue mechanical behavior of bone cement with elevated barium sulfate content for treatment of vertebral compression fractures
    S M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Biomaterials 26:3699-712. 2005
  5. ncbi request reprint Failure property distributions for conventional and highly crosslinked ultrahigh molecular weight polyethylenes
    S M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, Pennsylvania, USA
    J Biomed Mater Res B Appl Biomater 73:214-20. 2005
  6. ncbi request reprint Analysis of a retrieved polyethylene total disc replacement component
    Steven M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Spine J 5:344-50. 2005
  7. ncbi request reprint Anisotropy and oxidative resistance of highly crosslinked UHMWPE after deformation processing by solid-state ram extrusion
    Steven M Kurtz
    Exponent, Inc, 3401 Market St, Suite 300, Philadelphia, PA 19104, USA
    Biomaterials 27:24-34. 2006
  8. pmc History and systematic review of wear and osteolysis outcomes for first-generation highly crosslinked polyethylene
    Steven M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Clin Orthop Relat Res 469:2262-77. 2011
  9. pmc International survey of primary and revision total knee replacement
    Steven M Kurtz
    Exponent, Inc, Philadelphia, PA 19104, USA
    Int Orthop 35:1783-9. 2011
  10. ncbi request reprint Polyethylene wear and rim fracture in total disc arthroplasty
    Steven M Kurtz
    Exponent, Inc, 3401 Market St, Suite 300, Philadelphia, PA 19104, USA
    Spine J 7:12-21. 2007

Detail Information

Publications86

  1. doi request reprint Advances in zirconia toughened alumina biomaterials for total joint replacement
    Steven M Kurtz
    Exponent, Inc, Philadelphia, PA, United States Drexel University, Philadelphia, PA, United States Electronic address
    J Mech Behav Biomed Mater 31:107-16. 2014
    ..The advancements that have been made in understanding the in vivo performance of ZTA are investigated. This article concludes with a discussion of gaps in the literature related to ceramic biomaterials and avenues for future research. ..
  2. doi request reprint Infection risk for primary and revision instrumented lumbar spine fusion in the Medicare population
    Steven M Kurtz
    Exponent, Inc, Philadelphia, Pennsylvania 19104, USA
    J Neurosurg Spine 17:342-7. 2012
    ..Although infection can be a devastating complication, due to its rarity it is difficult to characterize infection risk except in large patient populations...
  3. doi request reprint Accelerated aqueous aging simulation of in vivo oxidation for gamma-sterilized UHMWPE
    Steven M Kurtz
    Exponent, Inc, Philadelphia, Pennsylvania, USA
    J Biomed Mater Res B Appl Biomater 90:368-72. 2009
    ..However, even at 50 degrees C over a year of in vitro aqueous aging will be necessary to reproduce the oxidation levels observed in long-term implanted acetabular retrievals. (..
  4. ncbi request reprint Static and fatigue mechanical behavior of bone cement with elevated barium sulfate content for treatment of vertebral compression fractures
    S M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Biomaterials 26:3699-712. 2005
    ....
  5. ncbi request reprint Failure property distributions for conventional and highly crosslinked ultrahigh molecular weight polyethylenes
    S M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, Pennsylvania, USA
    J Biomed Mater Res B Appl Biomater 73:214-20. 2005
    ..The data support the use of both parametric and nonparametric methods to bracket the lower-bound failure prediction in order to simulate the failure threshold for UHMWPE...
  6. ncbi request reprint Analysis of a retrieved polyethylene total disc replacement component
    Steven M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Spine J 5:344-50. 2005
    ..Although total disc replacements have been performed in Europe since the 1980s, this type of surgery is still new in the United States. The clinical performance of polyethylene in total disc replacements is still not well understood...
  7. ncbi request reprint Anisotropy and oxidative resistance of highly crosslinked UHMWPE after deformation processing by solid-state ram extrusion
    Steven M Kurtz
    Exponent, Inc, 3401 Market St, Suite 300, Philadelphia, PA 19104, USA
    Biomaterials 27:24-34. 2006
    ..The oxidative stability observed in ArComXL suggests that the deformation-processed material may be suitable for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted highly crosslinked UHMWPE...
  8. pmc History and systematic review of wear and osteolysis outcomes for first-generation highly crosslinked polyethylene
    Steven M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Clin Orthop Relat Res 469:2262-77. 2011
    ....
  9. pmc International survey of primary and revision total knee replacement
    Steven M Kurtz
    Exponent, Inc, Philadelphia, PA 19104, USA
    Int Orthop 35:1783-9. 2011
    ..g., age, gender) vary internationally? (3) How have the rates of TKA utilization changed over time?..
  10. ncbi request reprint Polyethylene wear and rim fracture in total disc arthroplasty
    Steven M Kurtz
    Exponent, Inc, 3401 Market St, Suite 300, Philadelphia, PA 19104, USA
    Spine J 7:12-21. 2007
    ..Polyethylene (PE) has been used in total disc replacements (TDRs) in Europe since the 1980s. However, the extent of surface damage of PE, including rim fracture and wear, after long-term implantation remains poorly understood...
  11. doi request reprint Accelerated aging, natural aging, and small punch testing of gamma-air sterilized polycarbonate urethane acetabular components
    S M Kurtz
    Exponent, Inc, Philadelphia, Pennsylvania 19104, USA
    J Biomed Mater Res B Appl Biomater 93:442-7. 2010
    ..Overall, our findings suggest that the Bionate 80A material has greater oxidative stability than ultra-high molecular weight polyethylene following gamma irradiation in air and exposure to a severe oxidative challenge...
  12. pmc PEEK biomaterials in trauma, orthopedic, and spinal implants
    Steven M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Biomaterials 28:4845-69. 2007
    ..For mature fields, such as total joint replacements and fracture fixation implants, radiolucency is an attractive but not necessarily critical material feature...
  13. doi request reprint Trace concentrations of vitamin E protect radiation crosslinked UHMWPE from oxidative degradation
    S M Kurtz
    Exponent, Inc, 3401 Market St, Suite 300, Philadelphia, Pennsylvania 19104, USA
    J Biomed Mater Res A 90:549-63. 2009
    ..The results of this experiment therefore supported our hypotheses that trace concentrations of Vitamin E, coupled with radiation treatment-but not resin grade-influence the mechanical and oxidative degradation behavior of UHMWPE...
  14. ncbi request reprint Deconvolution of surface topology for quantification of initial wear in highly cross-linked acetabular components for THA
    S M Kurtz
    Exponent, Inc, 2300 Chestnut St, Suite 150, Philadelphia, Pennsylvania 19103, USA
    J Biomed Mater Res 63:492-500. 2002
    ..The distinction between waviness and roughness is expected to be crucial for the comprehensive evaluation of wear surfaces after short-term implantation, when machining marks may be partially worn away or plastically deformed in vivo...
  15. ncbi request reprint Thermomechanical behavior of virgin and highly crosslinked ultra-high molecular weight polyethylene used in total joint replacements
    S M Kurtz
    Exponent, Inc, Philadelphia, PA 19103, USA
    Biomaterials 23:3681-97. 2002
    ..The data collected in this study will be used to develop constitutive models based on the physics of polymer systems for predicting the thermomechanical behavior of conventional and crosslinked UHMWPE used in total joint replacements...
  16. ncbi request reprint Simulation of initial frontside and backside wear rates in a modular acetabular component with multiple screw holes
    S M Kurtz
    Exponent Failure Analysis Associates, Inc, Philadelphia, PA 19103, USA
    J Biomech 32:967-76. 1999
    ..The results of this study suggest that with a polished metal shell, the presence of screw holes does not substantially increase abrasive backside wear when compared with the effects of backside nonconformity...
  17. ncbi request reprint Radiation and chemical crosslinking promote strain hardening behavior and molecular alignment in ultra high molecular weight polyethylene during multi-axial loading conditions
    S M Kurtz
    Exponent Failure Analysis Associates Inc, Philadelphia, PA 19103, USA
    Biomaterials 20:1449-62. 1999
    ..The data also illustrate the sensitivity of large deformation mechanical behavior and crystalline morphology to the method of crosslinking and resin of polyethylene...
  18. ncbi request reprint Advances in the processing, sterilization, and crosslinking of ultra-high molecular weight polyethylene for total joint arthroplasty
    S M Kurtz
    Exponent Failure Analysis Associates, Philadelphia, PA 19103, USA
    Biomaterials 20:1659-88. 1999
    ..Finally, the fourth part reviews the development and properties of crosslinked UHMWPE, a promising alternate biomaterial for total joint replacements...
  19. ncbi request reprint The relationship between the clinical performance and large deformation mechanical behavior of retrieved UHMWPE tibial inserts
    S M Kurtz
    Exponent Failure Analysis Associates, Philadelphia, PA 19103, USA
    Biomaterials 21:283-91. 2000
    ..Thus, the results of this study support the hypothesis that the clinical performance of UHMWPE tibial inserts is related to the large-deformation mechanical behavior measured near the articulating surface...
  20. ncbi request reprint A miniature specimen mechanical testing technique scaled to articulating surface of polyethylene components for total joint arthroplasty
    S M Kurtz
    Exponent Failure Analysis Associates, Inc, Philadelphia, Pennsylvania, USA
    J Biomed Mater Res 48:75-81. 1999
    ..In the future, the small punch test can be used to directly measure mechanical properties near the articulating surface of retrieved components...
  21. ncbi request reprint Surface morphology and wear mechanisms of four clinically relevant biomaterials after hip simulator testing
    S M Kurtz
    Exponent, Inc, 2300 Chestnut Street, Suite 150, Philadelphia, Pennsylvania 19103, USA
    J Biomed Mater Res 52:447-59. 2000
    ..01, r(2) = 0.54-0.81). The results support the hypothesis that wear mechanisms of acetabular liners during hip simulator testing are related to surface morphology in conjunction with the mechanical behavior of the polymeric materials...
  22. ncbi request reprint Interlaboratory reproducibility of standard accelerated aging methods for oxidation of UHMWPE
    S M Kurtz
    Exponent Inc, and Drexel University, Philadelphia, PA 19103, USA
    Biomaterials 22:1731-7. 2001
    ..However, the large interinstitutional variation suggests that absolute performance standards for the oxidation index of UHMWPE after accelerated aging may not be practical at the present time...
  23. ncbi request reprint Interlaboratory validation of oxidation-index measurement methods for UHMWPE after long-term shelf aging
    S M Kurtz
    Exponent, Inc, Philadelphia, Pennsylvania 19103, USA
    J Biomed Mater Res 63:15-23. 2002
    ..Therefore, both the 1370-cm(-1) and the 2022-cm(-1) reference peaks appear equally suitable for use in defining a standard method for calculating an oxidation index for UHMWPE...
  24. ncbi request reprint Interlaboratory studies to determine optimal analytical methods for measuring the oxidation index of UHMWPE
    S M Kurt
    Exponent Inc, Philadelphia, PA 19103, USA
    Biomaterials 22:2875-81. 2001
    ..2%. The results of this interlaboratory research will be a useful basis for the development of a new oxidation index standard for the orthopedics community...
  25. ncbi request reprint Miniature specimen shear punch test for UHMWPE used in total joint replacements
    S M Kurt
    Exponent, Inc, Philadelphia, PA 19103, USA
    Biomaterials 23:1907-19. 2002
    ..Thus, the shear punch test represents an effective and complementary new tool in the armamentarium of miniature specimen mechanical testing methods for UHMWPE used in total joint replacement components...
  26. ncbi request reprint Backside nonconformity and locking restraints affect liner/shell load transfer mechanisms and relative motion in modular acetabular components for total hip replacement
    S M Kurtz
    Failure Analysis Associates, Inc, Menlo Park, CA 94025, USA
    J Biomech 31:431-7. 1998
    ..Consequently, the results of this study demonstrate that backside nonconformity and locking restraints substantially influence backside relative motion as well as load transfer at the liner/shell interface...
  27. doi request reprint The natural history of polyethylene oxidation in total disc replacement
    Steven M Kurtz
    Drexel University, Philadelphia, PA 19104, USA
    Spine (Phila Pa 1976) 34:2369-77. 2009
    ..Forty-eight CHARITE TDRs were retrieved from 41 patients after 7.8 years of average implantation. All implants were removed because of intractable back pain and/or facet degeneration. Three unimplanted implants served as controls...
  28. ncbi request reprint An augmented hybrid constitutive model for simulation of unloading and cyclic loading behavior of conventional and highly crosslinked UHMWPE
    J S Bergström
    Exponent, Inc, 21 Strathmore Road, Natick, MA 01760, USA
    Biomaterials 25:2171-8. 2004
    ..The augmented hybrid constitutive model will be used as a critical building block in future studies of fatigue, failure, and wear of UHMWPE...
  29. ncbi request reprint Validation of a small punch testing technique to characterize the mechanical behaviour of ultra-high-molecular-weight polyethylene
    S M Kurtz
    Failure Analysis Associates, Inc, Philadelphia, PA 19103, USA
    Biomaterials 18:1659-63. 1997
    ..The ultimate goal of this research is to develop the capability to perform local measurements of material tensile and static fracture properties in as-manufactured, as-sterilized and as-retrieved UHMWPE components...
  30. ncbi request reprint Prediction of multiaxial mechanical behavior for conventional and highly crosslinked UHMWPE using a hybrid constitutive model
    J S Bergström
    Exponent, Inc, 21 Strathmore Rd, Natick, MA, USA
    Biomaterials 24:1365-80. 2003
    ..Most importantly, from a practical perspective, these four key material properties for the Hybrid constitutive model can be measured by relatively simple uniaxial tension or compression tests...
  31. ncbi request reprint Constitutive modeling of ultra-high molecular weight polyethylene under large-deformation and cyclic loading conditions
    J S Bergström
    Exponent, Inc, Natick, MA 01760, USA
    Biomaterials 23:2329-43. 2002
    ..In addition a new hybrid model is proposed, which incorporates many features of the previous theories. This hybrid model is shown to most effectively predict the experimentally observed mechanical behavior of UHMWPE...
  32. ncbi request reprint In vivo degradation of polyethylene liners after gamma sterilization in air
    Steven M Kurtz
    Implant Research Center, School of Biomedical Engineering, Science, and Health Systems and Department of Materials Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA
    J Bone Joint Surg Am 87:815-23. 2005
    ..The purpose of this study was to quantify the extent to which the mechanical properties and oxidation of conventional polyethylene acetabular liners treated with gamma sterilization in air change in vivo...
  33. ncbi request reprint How have new designs and new types of joint replacement influenced wear behavior?
    Steven M Kurtz
    Exponent, Inc, Philadelphia, PA, USA
    J Am Acad Orthop Surg 16:S107-10. 2008
    ..Advances in these types of implants have the potential for major clinical impact in the coming decade, due to the large number of patients seeking treatment of knee arthritis as well as back pain, neck pain, and radiculopathy...
  34. doi request reprint Two-year cost comparison of vertebroplasty and kyphoplasty for the treatment of vertebral compression fractures: are initial surgical costs misleading?
    K L Ong
    Exponent, Inc, 3401 Market St, Suite 300, Philadelphia, PA 19104, USA
    Osteoporos Int 24:1437-45. 2013
    ..8-7.9% in the remaining periods through 2 years postsurgery...
  35. ncbi request reprint Molecular chain stretch is a multiaxial failure criterion for conventional and highly crosslinked UHMWPE
    J S Bergström
    Exponent, Inc, 21 Strathmore Road, Natick, MA 01760, USA
    J Orthop Res 23:367-75. 2005
    ..These results lay the foundation for future developments of damage and wear models capable of predicting multiaxial failure under cyclic loading conditions...
  36. pmc Mechanical properties, oxidation, and clinical performance of retrieved highly cross-linked Crossfire liners after intermediate-term implantation
    Steven M Kurtz
    Implant Research Center, School of Biomedical Engineering, Science, and Health, Systems, Drexel University, Philadelphia, PA 19104, USA
    J Arthroplasty 25:614-23.e1-2. 2010
    ..Rim surface damage, however, was observed in only 3 (5%) of 60 cases. Retrieval analysis of the 3 rim-damaged liners did not reveal an association between surface damage and the reasons for revision...
  37. ncbi request reprint Multiaxial fatigue behavior of conventional and highly crosslinked UHMWPE during cyclic small punch testing
    M L Villarraga
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, Pennsylvania 19104, USA
    J Biomed Mater Res A 66:298-309. 2003
    ..Our long-term goal in this research is to develop miniature-specimen fatigue testing techniques for characterization of retrieved UHMWPE inserts...
  38. ncbi request reprint [Stress levels in bones and bone cement in the thoracolumbar spine afer kyphoplasty. Finite element study]
    L M Villarraga Ph D
    Exponent Inc, Philadelphia, PA 19104, USA
    Orthopade 33:48-55. 2004
    ..The presence of bone cement immediately following kyphoplasty has only a slight effect on the stress magnitudes or distributions in adjacent vertebrae...
  39. ncbi request reprint Predictive model for tensile true stress-strain behavior of chemically and mechanically degraded ultrahigh molecular weight polyethylene
    S M Kurtz
    Failure Analysis Associates, Philadelphia, Pennsylvania 19103, USA
    J Biomed Mater Res 43:241-8. 1998
    ..In the future, the material model data presented in this study will enable more accurate prediction of the stresses and strains in UHMWPE components following gamma sterilization in air and subsequent in vivo degradation...
  40. ncbi request reprint Clinical, surface damage and oxidative performance of poly II tibial inserts after long-term implantation
    Francisco Medel
    Implant Research Center, School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA
    J Long Term Eff Med Implants 18:151-65. 2008
    ..This study provides improved understanding of well-consolidated Poly II long-term retrievals and also motivation to revisit carbon fiber-reinforced polymeric bearings for joint replacement in the twenty-first century...
  41. pmc What is the correlation of in vivo wear and damage patterns with in vitro TDR motion response?
    Steven M Kurtz
    Implant Research Center, School of Biomedical Engineering, Science, Drexel University, Philadelphia, PA, USA
    Spine (Phila Pa 1976) 33:481-9. 2008
    ..3 years average implantation. All implants were removed because of intractable back pain and/or facet degeneration. In parallel, 20 new implants were evaluated at L4-L5 and L5-S1 in an in vitro lumbar spine model...
  42. doi request reprint Biomechanical comparison of 2 proximally coated femoral stems: effects of stem length and surface finish
    Kevin L Ong
    Biomechanics Practice, Exponent, Inc, Philadelphia, Pennsylvania 19104, USA
    J Arthroplasty 24:819-24. 2009
    ..Increased pain incidence for short-stem patients may be related to decreased implant instability and increased interface relative motion...
  43. doi request reprint Life expectancy following diagnosis of a vertebral compression fracture
    A A Edidin
    Medtronic, Inc, 1221 Crossman Ave, Sunnyvale, CA 94089, USA
    Osteoporos Int 24:451-8. 2013
    ..Kyphoplasty patients had a 34% greater adjusted life expectancy than vertebroplasty patients...
  44. ncbi request reprint Biomechanics of the Birmingham hip resurfacing arthroplasty
    K L Ong
    Exponent Incorporated, Philadelphia, Pennsylvania 19104, USA
    J Bone Joint Surg Br 88:1110-5. 2006
    ..The remodelling of bone seen during revision of failed Birmingham hip resurfacing implants appears to be consistent with the predictions of our finite element analysis...
  45. ncbi request reprint Digital photogrammetry for quantitative wear analysis of retrieved TKA components
    J C Grochowsky
    Implant Research Center, School of Biomedical Engineering, Drexel University, Philadelphia, PA 19104, USA
    J Biomed Mater Res B Appl Biomater 79:263-7. 2006
    ..Photogrammetry has a broad range of applicability since it is size- and design-independent. A minimal amount of off-the-shelf equipment is needed for the procedure and no proprietary knowledge of the implant is needed...
  46. ncbi request reprint Degradation of mechanical properties of UHMWPE acetabular liners following long-term implantation
    Steven M Kurtz
    Implant Research Center, School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA
    J Arthroplasty 18:68-78. 2003
    ..The results of this study strongly support the hypothesis that the degradation of mechanical properties for the liners occurred during implantation...
  47. ncbi request reprint 2006 Otto Aufranc Award Paper: significance of in vivo degradation for polyethylene in total hip arthroplasty
    Steven M Kurtz
    Implant Research Center, School of Biomedical Engineering, Science, and Health Systems and Department of Materials Engineering, Drexel University, Philadelphia, PA, USA
    Clin Orthop Relat Res 453:47-57. 2006
    ..We conclude that in vivo degradation should be included among the list of potential long-term failure modes for modular polyethylene components for total hip arthroplasty...
  48. doi request reprint Role of surgical position on interface stress and initial bone remodeling stimulus around hip resurfacing arthroplasty
    Kevin L Ong
    Exponent, Inc, Philadelphia, Pennsylvania 19140, USA
    J Arthroplasty 24:1137-42. 2009
    ..These data show bone loading and interface fixation trends emanating from valgus and varus implant positions that will be of interest to practicing physicians...
  49. pmc Risk of subsequent revision after primary and revision total joint arthroplasty
    Kevin L Ong
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Clin Orthop Relat Res 468:3070-6. 2010
    ..Understanding the relative risk of rerevision and risk factors can help identify patients at high risk who may require closer postsurgical care...
  50. doi request reprint Total disc replacement positioning affects facet contact forces and vertebral body strains
    Steven A Rundell
    Exponent Inc, Philadelphia, PA 19104, USA
    Spine (Phila Pa 1976) 33:2510-7. 2008
    ..The model was implanted with a fixed-bearing TDR (ProDisc-L) at 2 surgically relevant positions and exercised about the 3 anatomic axes. Facet forces, range of motion (RoM), and vertebral body strains were evaluated...
  51. doi request reprint Biomechanical modeling of acetabular component polyethylene stresses, fracture risk, and wear rate following press-fit implantation
    Kevin L Ong
    Exponent Inc, 3401 Market St, Suite 300, Philadelphia, Pennsylvania 19104, USA
    J Orthop Res 27:1467-72. 2009
    ..9 and 3.8 mm-thick liners, respectively. Although pinching increases liner stresses, polyethylene fracture is highly unlikely, and the volumetric wear rates are likely to be low compared to conventional polyethylene...
  52. doi request reprint Strength and reliability of alumina ceramic femoral heads: Review of design, testing, and retrieval analysis
    Roland Huet
    Exponent, Inc, 149 Commonwealth Drive, Menlo Park, CA 94025, USA
    J Mech Behav Biomed Mater 4:476-83. 2011
    ....
  53. doi request reprint Off-label use of bone morphogenetic proteins in the United States using administrative data
    Kevin L Ong
    Exponent Inc, Philadelphia, PA 19104, USA
    Spine (Phila Pa 1976) 35:1794-800. 2010
    ..Epidemiological study using national administrative data...
  54. pmc Wear pattern observations from TDR retrievals using autoregistration of voxel data
    Yakov P Shkolnikov
    Exponent, Inc, 3401 Market St, Suite 300, Philadelphia, Pennsylvania 19104, USA
    J Biomed Mater Res B Appl Biomater 94:312-7. 2010
    ....
  55. doi request reprint Effect of nucleus replacement device properties on lumbar spine mechanics
    Steven A Rundell
    Exponent Inc, Philadelphia, PA 19104, USA
    Spine (Phila Pa 1976) 34:2022-32. 2009
    ..A validated nonlinear three-dimensional finite element model of a single lumbar motion segment (L3-L4) was used to evaluate a range of moduli for ideally conforming nucleus replacement devices...
  56. pmc Gamma inert sterilization: a solution to polyethylene oxidation?
    Francisco J Medel
    Implant Research Center, School of Biomedical Engineering, Science and Health Systems, Drexel University, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    J Bone Joint Surg Am 91:839-49. 2009
    ..In addition, the potential influence of the different sterilization processes on the wear performance of the polyethylene components was examined...
  57. doi request reprint Have contemporary hip resurfacing designs reached maturity? A review
    Kevin L Ong
    Exponent Incorporated, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    J Bone Joint Surg Am 90:81-8. 2008
    ..In addition, this review is based on an understanding of the causes of failure of revision hip resurfacing arthroplasty, which is essential to help guide research, implant design, and clinical decision-making...
  58. ncbi request reprint The biomechanical effects of kyphoplasty on treated and adjacent nontreated vertebral bodies
    Marta L Villarraga
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    J Spinal Disord Tech 18:84-91. 2005
    ..Therefore, subsequent adjacent level fractures may be related to the underlying etiology (weakening of the bone) rather than the surgical intervention...
  59. ncbi request reprint Can accelerated aqueous aging simulate in vivo oxidation of gamma-sterilized UHMWPE?
    Daniel C Mazzucco
    Exponent, Inc, Philadelphia, Pennsylvania 19104, USA
    J Biomed Mater Res B Appl Biomater 79:79-85. 2006
    ....
  60. ncbi request reprint Future clinical and economic impact of revision total hip and knee arthroplasty
    Steven M Kurtz
    Exponent Incorporated, Philadelphia, PA 19104, USA
    J Bone Joint Surg Am 89:144-51. 2007
  61. doi request reprint Prevalence and projections of total shoulder and elbow arthroplasty in the United States to 2015
    Judd S Day
    Biomechanics Practice, Exponent Inc, Philadelphia, PA 19104, USA
    J Shoulder Elbow Surg 19:1115-20. 2010
    ....
  62. doi request reprint Prosthetic joint infection risk after total hip arthroplasty in the Medicare population
    Kevin L Ong
    Exponent, Inc, Philadelphia, Pennsylvania 19104, USA
    J Arthroplasty 24:105-9. 2009
    ..This is the first study to establish the incidence and risk factors associated with early onset and delayed periprosthetic joint infection in the Medicare patient population...
  63. pmc Distinct immunohistomorphologic changes in periprosthetic hip tissues from historical and highly crosslinked UHMWPE implant retrievals
    Ryan M Baxter
    Department of Biomedical Engineering, School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania 19104, USA
    J Biomed Mater Res A 95:68-78. 2010
    ....
  64. pmc On the assessment of oxidative and microstructural changes after in vivo degradation of historical UHMWPE knee components by means of vibrational spectroscopies and nanoindentation
    Francisco J Medel
    Implant Research Center, School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania 19104, USA
    J Biomed Mater Res A 89:530-8. 2009
    ..Furthermore, infrared spectroscopy alone appeared to provide excellent insight into the oxidation and crystallization state of the in vivo oxidized polyethylene...
  65. doi request reprint Effect of procedure duration on total hip arthroplasty and total knee arthroplasty survivorship in the United States Medicare population
    Kevin L Ong
    Exponent, Inc, Philadelphia, Pennsylvania 19104, USA
    J Arthroplasty 23:127-32. 2008
    ..Our findings support the general belief that longer procedures are associated with the greater probability of complications...
  66. pmc Prosthetic joint infection risk after TKA in the Medicare population
    Steven M Kurtz
    Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA
    Clin Orthop Relat Res 468:52-6. 2010
    ..PJI occurs at a relatively high rate in Medicare patients with the greatest risk of PJI within the first 2 years after surgery; however, approximately one-fourth of all PJIs occur after 2 years...
  67. doi request reprint Infection burden for hip and knee arthroplasty in the United States
    Steven M Kurtz
    Exponent Inc, Philadelphia, Pennsylvania 19104, USA
    J Arthroplasty 23:984-91. 2008
    ..26% for knees compared to rural (0.61% for hips and 0.69% for knees) and urban-teaching hospitals (0.73% for hips and 0.77% for knees). We found an increasing number of joint arthroplasties being diagnosed with periprosthetic infection...
  68. ncbi request reprint An in vitro model for fluid pressurization of screw holes in metal-backed total joint components
    Steven M Kurtz
    Exponent, Inc, Philadelphia, PA 19104, USA
    J Arthroplasty 20:932-8. 2005
    ....
  69. pmc Future young patient demand for primary and revision joint replacement: national projections from 2010 to 2030
    Steven M Kurtz
    Exponent Inc, Philadelphia, PA 19104, USA
    Clin Orthop Relat Res 467:2606-12. 2009
    ..Level of Evidence: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence...
  70. pmc Mechanical properties of retrieved highly cross-linked crossfire liners after short-term implantation
    Steven M Kurtz
    Implant Research Center, School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA
    J Arthroplasty 20:840-9. 2005
    ..We conclude that the variability in polyethylene properties observed in this small study was not clinically significant for these short-term-implanted, annealed cross-linked liners...
  71. ncbi request reprint Economic burden of revision hip and knee arthroplasty in Medicare enrollees
    K L Ong
    Exponent Inc, Philadelphia, PA, USA
    Clin Orthop Relat Res 446:22-8. 2006
    ..Level of Evidence: Prognostic study, level II-1 (retrospective study). See Guidelines for Authors for a complete description of levels of evidence...
  72. doi request reprint Patient, hospital, and procedure characteristics influencing total hip and knee arthroplasty procedure duration
    Kevin Ong
    Exponent, Inc, Philadelphia, Pennsylvania, USA
    J Arthroplasty 24:925-31. 2009
    ..This analysis provides baseline data for future investigation of the influence of procedure duration on total joint arthroplasty outcomes from a national perspective...
  73. doi request reprint Implantation trends and patient profiles for pacemakers and implantable cardioverter defibrillators in the United States: 1993-2006
    Steven M Kurtz
    Exponent, Inc, and Implant Research Center, School of Biomedical Engineering, Science, and Heath Systems, Drexel University, Philadelphia, Pennsylvania, USA
    Pacing Clin Electrophysiol 33:705-11. 2010
    ..We evaluated the national trends for the implantation of PMs and ICDs including the burden of device replacement...
  74. doi request reprint Primary and revision arthroplasty surgery caseloads in the United States from 1990 to 2004
    Steven M Kurtz
    Exponent Inc, Philadelphia, Pennsylvania 19104, USA
    J Arthroplasty 24:195-203. 2009
    ..The revision caseload of surgeons has increased over time, particularly for surgeons with the highest caseloads...
  75. ncbi request reprint Fatigue crack propagation resistance of virgin and highly crosslinked, thermally treated ultra-high molecular weight polyethylene
    Sara J Gencur
    Musculoskeletal Mechanics and Materials Laboratories, Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106 7222, USA
    Biomaterials 27:1550-7. 2006
    ..Scanning electron microscopy examination of the fracture surfaces demonstrated that the virgin treatment group failed in a more ductile manner than the two highly crosslinked treatment groups...
  76. ncbi request reprint Oxidation and oxidation potential in contemporary packaging for polyethylene total joint replacement components
    Luigi Costa
    Department of I F M Chemistry and NIS Center of Excellence, University of Turin, Via Giuria 7, 10125 Italy
    J Biomed Mater Res B Appl Biomater 78:20-6. 2006
    ..To the authors' knowledge, this is the first study that relates elevated oxidation and hydroperoxide content in gamma-sterilized PE components to certain types of contemporary, polymeric barrier packaging...
  77. ncbi request reprint Large deformation compression induced crystallinity degradation of conventional and highly crosslinked UHMWPEs
    Michael C Sobieraj
    Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 620 Glennan Building, Cleveland, OH, USA
    Biomaterials 26:6430-9. 2005
    ..The findings of this study support that microstructural evolution during compressive deformation is a function of UHMWPE formulation, as affected by irradiation and post-irradiation heat treatment...
  78. ncbi request reprint How have new sterilization techniques and new forms of polyethylene influenced wear in total joint replacement?
    Roy D Crowninshield
    Department of Orthopedic Surgery, Rush Medical College, Chicago, IL, USA
    J Am Acad Orthop Surg 16:S80-5. 2008
    ..Newer second-generation methods of cross-linking polyethylene include the use of vitamin E, which quenches free radicals and demonstrates promise in providing low wear and desirable mechanical properties...
  79. ncbi request reprint The potential for bone loss in acetabular structures following THA
    Michael T Manley
    Stryker Orthopaedics, Mahwah, NJ, USA
    Clin Orthop Relat Res 453:246-53. 2006
    ..Radical changes in implant design may be necessary for long-term maintenance of supporting structures in the reconstructed acetabulum...
  80. pmc Complications and reoperations of the SB Charité lumbar disc prosthesis: experience in 75 patients
    Ilona M Punt
    Department of Orthopaedic Surgery, University Hospital Maastricht, Postbox 5800, 6202 AZ Maastricht, The Netherlands
    Eur Spine J 17:36-43. 2008
    ..Removal of the SB Charité artificial disc is feasible but with inherent risks. Removal of the disc prosthesis gives slightly better results than posterior fusion alone after a follow-up of at least 1 year...
  81. ncbi request reprint Polyethylene wear debris and long-term clinical failure of the Charité disc prosthesis: a study of 4 patients
    Andre van Ooij
    Department of Orthopaedic Surgery, University Hospital Maastricht, Maastricht, The Netherlands
    Spine (Phila Pa 1976) 32:223-9. 2007
    ..A clinical case series of 4 patients undergoing anterior lumbar revision due to failure of total disc replacement surgery...
  82. ncbi request reprint How do alternative bearing surfaces influence wear behavior?
    Ian C Clarke
    Peterson Research Center, Loma Linda University, Loma Linda, CA, USA
    J Am Acad Orthop Surg 16:S86-93. 2008
    ..Thus, the role of laboratory studies is to isolate relevant aspects of performance by cup design and to predict the risk-benefit ratios in patients requiring total hip replacement...
  83. ncbi request reprint What design factors influence wear behavior at the bearing surfaces in total joint replacements?
    Thomas D Brown
    Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA, USA
    J Am Acad Orthop Surg 16:S101-6. 2008
    ..However, untoward complexities occurring in vivo, such as impingement or third-body challenge, can appreciably compromise wear performance even for implants that are well-designed in terms of bearing surface stress minimization...
  84. ncbi request reprint How have wear testing and joint simulator studies helped to discriminate among materials and designs?
    Harry A McKellop
    Department of Orthopaedic Surgery, UCLA Orthopaedic Hospital, Los Angeles, CA, USA
    J Am Acad Orthop Surg 16:S111-9. 2008
    ....
  85. ncbi request reprint How do material properties influence wear and fracture mechanisms?
    Clare Rimnac
    Case Western Reserve University, Cleveland, OH, USA
    J Am Acad Orthop Surg 16:S94-100. 2008
    ..Mechanical tests as well as computational material and structural models should be developed to evaluate the combined effect of material and geometry (structure) on fracture resistance under clinically relevant loading conditions...
  86. doi request reprint Effect of volume on total hip arthroplasty revision rates in the United States Medicare population
    Michael Manley
    Homer Stryker Center for Orthopaedic Education, 325 Corporate Drive, Mahwah, NJ 07430, USA
    J Bone Joint Surg Am 90:2446-51. 2008
    ..We examined the association between hospital and surgeon procedure volume and total hip arthroplasty revision rates in the Medicare population at six months to eight years postoperatively...