title: A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.
abstract: Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models.
authors.affiliation: Musculoskeletal Science Research Center, Institute for Human Performance (3217), SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA. racea@upstate.edu
authors.forename: Amos
authors.initials: A
authors.lastname: Race
authors.forename: Mark A
authors.initials: MA
authors.lastname: Miller
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Mann
mesh_terms: D001843:Bone Cements / Q000737:chemistry*; D002102:Cadaver; D002484:Cementation / Q000379:methods*; D055119:Elastic Modulus; D019544:Equipment Failure Analysis / Q000379:methods*; D006244:Hardness; D006801:Humans; D007595:Joint Prosthesis; D008422:Materials Testing; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D019919:Prosthesis Implantation / Q000379:methods*; D013314:Stress, Mechanical; D014783:Viscosity
chemical_list: D001843:Bone Cements; D019904:Polymethyl Methacrylate
references.citation: J Arthroplasty. 2000 Dec;15(8):1028-35
references.pmid: 11112200
references.citation: Clin Orthop Relat Res. 1997 Nov;(344):94-110
references.pmid: 9372762
references.citation: Acta Orthop. 2006 Apr;77(2):177-97
references.pmid: 16752278
references.citation: J Bone Joint Surg Br. 2002 Nov;84(8):1199-204
references.pmid: 12463671
references.citation: Acta Orthop. 2005 Oct;76(5):679-87
references.pmid: 16263615
references.citation: J Orthop Res. 2002 Jul;20(4):676-82
references.pmid: 12168654
references.citation: J Orthop Res. 2007 Mar;25(3):340-50
references.pmid: 17149748
references.citation: Clin Orthop Relat Res. 2003 Apr;(409):138-50
references.pmid: 12671496
references.citation: Proc Inst Mech Eng H. 2007 Aug;221(6):585-99
references.pmid: 17937198
references.citation: J Biomed Mater Res B Appl Biomater. 2008 Jul;86(1):278-82
references.pmid: 18161813
references.citation: J Biomed Mater Res. 1995 May;29(5):575-81
references.pmid: 7622542
references.citation: Clin Orthop Relat Res. 2000 Dec;(381):9-25
references.pmid: 11127675
references.citation: J Appl Biomater. 1994;5(3):235-43
references.pmid: 10147450
references.citation: J Biomech Eng. 2005 Oct;127(5):872-80
references.pmid: 16248319
references.citation: Proc Inst Mech Eng H. 2007 Aug;221(6):569-84
references.pmid: 17937197
references.citation: J Arthroplasty. 2000 Dec;15(8):1036-50
references.pmid: 11112201
references.citation: Acta Orthop Scand. 1993 Dec;64(6):699-716
references.pmid: 8291421
references.citation: J Biomech. 2001 Jul;34(7):917-26
references.pmid: 11410175
references.citation: J Bone Joint Surg Br. 1991 Jul;73(4):551-8
references.pmid: 2071634
references.citation: J Biomech. 2003 Nov;36(11):1603-15
references.pmid: 14522201
references.citation: J Biomech. 2002 Feb;35(2):257-65
references.pmid: 11784544
references.citation: J Biomech. 1996 Apr;29(4):525-35
references.pmid: 8964782
references.citation: J Biomech. 2002 Mar;35(3):311-21
references.pmid: 11858806
references.citation: Acta Orthop Scand. 1990 Jun;61(3):273-4
references.pmid: 2371828
references.citation: Acta Orthop. 2006 Aug;77(4):607-16
references.pmid: 16929438