title: A radiological analysis of the difference between MRI- and CT-based patient-specific matched guides for total knee arthroplasty from the same manufacturer: a randomised controlled trial.
abstract: OBJECTIVE
  This prospective randomised controlled trial was designed to evaluate the outcome of both the MRI- and CT-based patient-specific matched guides (PSG) from the same manufacturer.
  
  
  METHODS
  A total of 137 knees in 137 patients (50 men, 87 women) were included, 67 in the MRI- and 70 in the CT-based PSG group. Their mean age was 68.4 years (47.0 to 88.9). Outcome was expressed as the biomechanical limb alignment (centre hip-knee-ankle: HKA-axis) achieved post-operatively, the position of the individual components within 3° of the pre-operatively planned alignment, correct planned implant size and operative data (e.g. operating time and blood loss).
  
  
  RESULTS
  The patient demographics (e.g. age, body mass index), correct planned implant size and operative data were not significantly different between the two groups. The proportion of outliers in the coronal and sagittal plane ranged from 0% to 21% in both groups. Only the number of outliers for the posterior slope of the tibial component showed a significant difference (p = 0.004) with more outliers in the CT group (n = 9, 13%) than in the MRI group (0%).
  
  
  CONCLUSIONS
  The post-operative HKA-axis was comparable in the MRI- and CT-based PSGs, but there were significantly more outliers for the posterior slope in the CT-based PSGs.
  
  
  CONCLUSIONS
  Alignment with MRI-based PSG is at least as good as, if not better, than that of the CT-based PSG, and is the preferred imaging modality when performing TKA with use of PSG. Cite this article: Bone Joint J 2016;98-B:786-92.
authors.affiliation: Zuyderland Medical Center, Dr H van der Hoffplein 1, Sittard-Geleen, 6162 BG, The Netherlands.
authors.forename: M G M
authors.initials: MG
authors.lastname: Schotanus
authors.affiliation: Sint Maartenskliniek, Hengstdal 3, 6574 NA Ubbergen, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Sollie
authors.affiliation: Zuyderland Medical Center, Dr H van der Hoffplein 1, Sittard-Geleen, 6162 BG, The Netherlands.
authors.forename: E H
authors.initials: EH
authors.lastname: van Haaren
authors.affiliation: Zuyderland Medical Center, Dr H van der Hoffplein 1, Sittard-Geleen, 6162 BG, The Netherlands.
authors.forename: R P M
authors.initials: RP
authors.lastname: Hendrickx
authors.affiliation: Zuyderland Medical Center, Dr H van der Hoffplein 1, Sittard-Geleen, 6162 BG, The Netherlands.
authors.forename: E J P
authors.initials: EJ
authors.lastname: Jansen
authors.affiliation: Zuyderland Medical Center, Dr H van der Hoffplein 1, Sittard-Geleen, 6162 BG, The Netherlands.
authors.forename: N P
authors.initials: NP
authors.lastname: Kort
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D017076:Computer-Aided Design; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D007720:Knee Prosthesis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D017755:Prosthesis Fitting / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed
keywords: Alignment; CT; Knee alignment; MRI; Patient matched instruments; Patient specific matched guides; Total knee arthroplasty