title: Polished trays reduce backside wear independent of post location in posterior-stabilized TKAs.
abstract: BACKGROUND
  Backside damage of the polyethylene in TKA is a potential source of debris. The location of the tibial post in posterior-stabilized implants may influence micromotion, and thus affect backside damage, as may surface roughness.
  
  
  OBJECTIVE
  We used implant retrieval analysis to (1) examine if there were differences in backside damage among three modern posterior-stabilized implants attributable to variable surface roughness; (2) determine if the location of damage on the tibial post affected the pattern of backside damage; and (3) determine if demographics influenced backside damage.
  
  
  METHODS
  We identified 403 posterior-stabilized tibial retrieved inserts (147 NexGen(®), 152 Optetrak(®), 104 Genesis(®) II). The damage on the surfaces of the tibial posts was previously graded. The backside of the inserts (divided into quadrants) were scored for evidence of damage. The total quadrant damage was compared for each implant group, the relationship between post face damage and location of damage on the backside was determined for each implant group, and total backside damage was compared among the three implant groups.
  
  
  RESULTS
  No correlation was found between the location of damage on the post and location of damage on the backside of the implant for any of the three groups. The Genesis(®) II polyethylene implants, which articulate with a highly polished tibial tray, showed a significantly lower total backside damage score (p < 0.01) when compared with the other two implant groups. The Genesis(®) II and Optetrak(®) showed significantly more damage in the posterior quadrants of the implants (p < 0.01) when compared with the anterior quadrants. A linear regression analysis revealed that lower tibial tray surface roughness was correlated with decreased damage.
  
  
  CONCLUSIONS
  An implant design with a highly polished tibial tray was associated with decreased backside damage. However, tibial post design and location did not influence the location of backside damage.
  
  
  CONCLUSIONS
  Our study showed that a highly polished tibial tray was associated with decreased damage to the backside of polyethylene inserts independent of post design and location. These findings should be taken into consideration when new generations of implants are designed.
authors.affiliation: Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, 535 East 70th Street, New York, NY, 10021, USA, abdel.matthew@mayo.edu.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Abdel
authors.forename: Mark W
authors.initials: MW
authors.lastname: Gesell
authors.forename: Christen W
authors.initials: CW
authors.lastname: Hoedt
authors.forename: Kathleen N
authors.initials: KN
authors.lastname: Meyers
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Wright
authors.forename: Steven B
authors.initials: SB
authors.lastname: Haas
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D020878:Device Removal; D019544:Equipment Failure Analysis; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D016014:Linear Models; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012307:Risk Factors; D013314:Stress, Mechanical; D013499:Surface Properties; D013977:Tibia / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D020959:Polyethylene
references.citation: J Arthroplasty. 2007 Sep;22(6):787-99
references.pmid: 17826267
references.citation: J Bone Joint Surg Am. 2004 May;86(5):1031-7
references.pmid: 15118049
references.citation: J Biomed Mater Res. 1983 Sep;17(5):829-42
references.pmid: 6619179
references.citation: Clin Orthop Relat Res. 2012 Jul;470(7):1860-8
references.pmid: 22314963
references.citation: J Bone Joint Surg Am. 2005 Feb;87(2):326-31
references.pmid: 15687155
references.citation: Clin Orthop Relat Res. 2007 May;458:137-44
references.pmid: 17242615
references.citation: J Bone Joint Surg Am. 2002 Oct;84(10):1849-55
references.pmid: 12377918
references.citation: HSS J. 2007 Feb;3(1):30-4
references.pmid: 18751767
references.citation: Clin Orthop Relat Res. 2008 Nov;466(11):2650-5
references.pmid: 18704615
references.citation: J Bone Joint Surg Am. 2000 Dec;82(12):1708-25
references.pmid: 11130644
references.citation: Clin Orthop Relat Res. 2011 Jan;469(1):160-7
references.pmid: 20711697
references.citation: J Biomech. 2010 May 7;43(7):1310-5
references.pmid: 20172525
references.citation: Clin Orthop Relat Res. 2002 Nov;(404):232-46
references.pmid: 12439265
references.citation: Clin Orthop Relat Res. 2003 May;(410):248-53
references.pmid: 12771836
references.citation: Clin Orthop Relat Res. 2002 Nov;(404):75-82
references.pmid: 12439241
references.citation: Clin Orthop Relat Res. 2004 Nov;(428):198-206
references.pmid: 15534543
references.citation: J Am Acad Orthop Surg. 1994 Jan;2(1):16-25
references.pmid: 10708990
references.citation: J Arthroplasty. 2010 Aug;25(5):820-5
references.pmid: 20638615
references.citation: J Bone Joint Surg Am. 1982 Sep;64(7):1026-33
references.pmid: 7118966
references.citation: Clin Orthop Relat Res. 2008 Nov;466(11):2798-805
references.pmid: 18791779
references.citation: Clin Orthop Relat Res. 1998 Nov;(356):10-5
references.pmid: 9917661
references.citation: Proc Inst Mech Eng H. 2008 Nov;222(8):1289-93
references.pmid: 19143421
references.citation: Clin Orthop Relat Res. 1997 Dec;(345):53-9
references.pmid: 9418621