title: The accuracy and precision of radiostereometric analysis in monitoring tibial plateau fractures.
abstract: OBJECTIVE
  The application of radiostereometric analysis (RSA) to monitor stability of tibial plateau fractures during healing is both limited and yet to be validated. We therefore evaluated the accuracy and precision of RSA in a tibial plateau fracture model.
  
  
  METHODS
  Combinations of 3, 6, and 9 markers in a lateral condyle fracture were evaluated with reference to 6 proximal tibial arrangements. Translation and rotation accuracy was assessed with displacement-controlled stages, while precision was assessed with dynamic double examinations. A comparison of error according to marker number and arrangement was completed with 2-way ANOVA models.
  
  
  RESULTS
  The results were improved using more tantalum markers in each segment. In the fracture fragment, marker scatter in all axes was achieved by a circumferential arrangement (medial, anterior, and lateral) of the tantalum markers above the fixation devices. Markers placed on either side of the tibial tuberosity and in the medial aspect of the fracture split represented the proximal tibial reference segment best. Using 6 markers with this distribution in each segment, the translation accuracy (root mean square error) was less than 37 mum in all axes. The precision (95% confidence interval) was less than +/- 16 mum in all axes in vitro. Rotation, tested around the x-axis, had an accuracy of less than 0.123 degrees and a precision of +/- 0.024 degrees.
  
  
  CONCLUSIONS
  RSA is highly accurate and precise in the assessment of lateral tibial plateau fracture fragment movement. The validation of our center's RSA system provides evidence to support future clinical RSA fracture studies.
authors.affiliation: Discipline of Orthopaedics and Trauma, University of Adelaide, Adelaide, Australia. bogdansolomon@mac.com
authors.forename: Lucian B
authors.initials: LB
authors.lastname: Solomon
authors.forename: Aaron W
authors.initials: AW
authors.lastname: Stevenson
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Callary
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Sullivan
authors.forename: Donald W
authors.initials: DW
authors.lastname: Howie
authors.forename: Mellick J
authors.initials: MJ
authors.lastname: Chehade
mesh_terms: D017102:Fracture Healing / Q000502:physiology*; D006801:Humans; D019047:Phantoms, Imaging; D010780:Photogrammetry / Q000379:methods / Q000592:standards; D017410:Practice Guidelines as Topic; D011859:Radiography; D015203:Reproducibility of Results; D012399:Rotation; D013978:Tibial Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology*
references.citation: J Orthop Trauma. 2007 Nov-Dec;21(10 Suppl):S1-133
references.pmid: 18277234
references.citation: J Orthop Trauma. 2008 Sep;22(8 Suppl):S96-105
references.pmid: 18753897
references.citation: J Biomech. 2004 Apr;37(4):487-93
references.pmid: 14996560
references.citation: Int Orthop. 1994 Jun;18(3):131-4
references.pmid: 7927960
references.citation: J Orthop Res. 2004 May;22(3):659-64
references.pmid: 15099649
references.citation: J Biomech. 2006;39(9):1641-50
references.pmid: 15990104
references.citation: Acta Orthop Scand. 2001 Feb;72(1):57-61
references.pmid: 11327415
references.citation: J Biomech. 1993 Dec;26(12):1473-7
references.pmid: 8308052
references.citation: Acta Orthop Scand. 1989 Aug;60(4):491-503
references.pmid: 2683567
references.citation: J Orthop Res. 2001 Nov;19(6):1162-7
references.pmid: 11781019
references.citation: Clin Orthop Relat Res. 2009 Jul;467(7):1839-47
references.pmid: 19184262
references.citation: J Biomech. 2000 Dec;33(12):1593-9
references.pmid: 11006383
references.citation: J Bone Joint Surg Am. 2005 Oct;87(10):2323-34
references.pmid: 16203901
references.citation: Acta Orthop Scand. 2000 Aug;71(4):403-8
references.pmid: 11028891
references.citation: J Orthop Res. 2002 Jul;20(4):688-95
references.pmid: 12168656
references.citation: J Biomech. 2000 Apr;33(4):493-8
references.pmid: 10768399
references.citation: Scand J Surg. 2006;95(2):119-27
references.pmid: 16821655
references.citation: J Orthop Sci. 2004;9(1):66-75
references.pmid: 14767707
references.citation: J Orthop Res. 2005 Mar;23(2):481-8
references.pmid: 15734266
references.citation: Scand J Surg. 2003;92(3):215-9
references.pmid: 14582545
references.citation: J Biomech. 2008;41(4):907-11
references.pmid: 18096170
references.citation: Acta Orthop. 2005 Aug;76(4):563-72
references.pmid: 16195075
references.citation: Clin Orthop Relat Res. 1979 Jan-Feb;(138):94-104
references.pmid: 445923