title: Pre-operative radiological measurement of femoral rotation for prosthetic positioning in total knee arthroplasty.
abstract: This study outlines the benefits of the seated view radiograph of the knee in evaluation of the pre-operative individual distal femoral torsion (DFT) and for the follow-up of the post-operative rotational positioning of the femoral component in total knee arthroplasty.
  
  
  
  Study on 20 patients who underwent total knee arthroplasty and the correlation between the DFT measured before surgery with this radiology view, the intra-operative external rotation (ER) necessary for the parallel positioning of the femoral component with the transepicondylar axis (TEA) and the post-operative femoral rotational alignment of the prosthesis on the same view.
  
  
  
  In 90 % of cases the values of internal DFT were between -1(0) and -8(0), while the mean value of the internal rotation (IR) was -4.45(0). The mean value of the ER applied to the posterior bone resection was 4.25(0) (0(0)-7(0)), showing a statistically significant correlation between the pre-operative measurement and the intra-operative one of the posterior condylar angle (PCA) (r = 0.890, p = 0.000). Residual internal femoral malrotation has been identified in four cases, its mean value being 0.4(0). In three patients the pre-operative value of the PCA was higher than the intra-operative one and an internal malrotation of the post-operative femoral component was observed.
  
  
  
  The results are encouraging for the further use of this pre-operative view with the premises of increasing the accuracy of prosthetic positioning and reducing the mechanical complications.
authors.affiliation: Department of Orthopedics and Trauma, Clinical Rehabilitation Hospital, Iasi, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania.
authors.forename: Liliana
authors.initials: L
authors.lastname: Savin
authors.affiliation: Department of Orthopedics and Trauma, Clinical Rehabilitation Hospital, Iasi, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania. paulbotez@yahoo.com.
authors.forename: Paul
authors.initials: P
authors.lastname: Botez
authors.affiliation: Department of Orthopedics and Trauma, Clinical Rehabilitation Hospital, Iasi, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania.
authors.forename: Dan
authors.initials: D
authors.lastname: Mihailescu
authors.affiliation: Department of Orthopedics and Trauma, St Pantelimon Clinical Hospital Bucharest, University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania.
authors.forename: Vlad
authors.initials: V
authors.lastname: Predescu
authors.affiliation: Department of Orthopedics and Trauma, Clinical Rehabilitation Hospital, Iasi, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania.
authors.forename: Carmen
authors.initials: C
authors.lastname: Grierosu
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D007719:Knee Joint; D007720:Knee Prosthesis; D008297:Male; D012399:Rotation; D014057:Tomography, X-Ray Computed
keywords: Distal femoral torsion; Prosthetic malrotation; Seated view radiography; Total knee arthroplasty