title: Feasibility of model-based Roentgen Stereophotogrammetric Analysis to evaluate early migration of the trapeziometacarpal joint prosthesis.
abstract: BACKGROUND
  The purpose of this study was to determine the feasibility of Roentgen Stereophotogrammetric Analysis (RSA) in total joint arthroplasty of the trapeziometacarpal (TMC) joint of the thumb.
  
  
  METHODS
  In five cadaveric hands the TMC-joint was replaced by the Surface Replacement Trapeziometacarpal prosthesis (SR™ TMC prosthesis; Avanta, San Diego, CA) and tantalum beads of 0.8 mm were implanted for RSA. RSA radiographs in two directions were made in ten positions to calculate the measurement error. Migration values from zero are indicative for the measurement error. The number of detected markers was recorded.
  
  
  RESULTS
  The accuracy analysis showed that for the translations the mean measurement error varied between 0.003 mm (SD 0.057) and 0.055 mm (SD 0.133). For the rotations values ranged from 0.034° (SD 1.759) to 0.502° (SD 1.617).
  
  
  CONCLUSIONS
  RSA analysis of the SR™ TMC prosthesis is feasible. The measurement error is good for the translations but high for the rotations. The latter is due to the close position of the markers relative to each other. Level of evidence III.
authors.affiliation: Centre for Orthopaedic Surgery, OCON, Hand and Wrist unit, Hengelo, The Netherlands. e.ooms@zgt.nl.
authors.forename: E M
authors.initials: EM
authors.lastname: Ooms
authors.affiliation: Department of Orthopaedic Surgery, Reinier de Graaf Groep, Delft, The Netherlands. barttenbrinke@gmail.com.
authors.forename: B
authors.initials: B
authors.lastname: ten Brinke
authors.affiliation: Department of Orthopaedic Surgery, Reinier de Graaf Groep, Delft, The Netherlands. n.mathijssen@rdgg.nl.
authors.forename: N M C
authors.initials: NM
authors.lastname: Mathijssen
authors.affiliation: Departments of Radiology and Orthopaedic Surgery, Reinier de Graaf Groep, P.O. Box 5011, 2600 GA, Delft, The Netherlands. i.blom@rdgg.nl.
authors.forename: I F
authors.initials: IF
authors.lastname: Blom
authors.affiliation: Department of Orthopaedic Surgery, Haga Ziekenhuis, Den Haag, The Netherlands. r.deijkers@deijkers.org.
authors.forename: R L M
authors.initials: RL
authors.lastname: Deijkers
authors.affiliation: Department of Orthopaedic Surgery, Reinier de Graaf Groep, Delft, The Netherlands. kraang@rdgg.nl.
authors.forename: G A
authors.initials: GA
authors.lastname: Kraan
mesh_terms: D005240:Feasibility Studies; D050823:Hand Joints / Q000000981:diagnostic imaging*; D006801:Humans; D007595:Joint Prosthesis / Q000009:adverse effects*; D059869:Radiostereometric Analysis