Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?

Adam J. Schwartz, Bheeshma Ravi, Mark J. Kransdorf, Henry D. Clarke

Research output: Contribution to journalArticle

Abstract

Background: A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Methods: Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Results: Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. Conclusion: The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph.

Original languageEnglish (US)
JournalJournal of Arthroplasty
DOIs
StateAccepted/In press - Jul 15 2016

Fingerprint

Knee Replacement Arthroplasties
Tibia
Cadaver
Leg
Tomography
Bone and Bones

Keywords

  • Alignment
  • Imaging
  • Rotation
  • Slope
  • Tibia
  • Total knee arthroplasty

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

Cite this

Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph? / Schwartz, Adam J.; Ravi, Bheeshma; Kransdorf, Mark J.; Clarke, Henry D.

In: Journal of Arthroplasty, 15.07.2016.

Research output: Contribution to journalArticle

Schwartz, Adam J. ; Ravi, Bheeshma ; Kransdorf, Mark J. ; Clarke, Henry D. / Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?. In: Journal of Arthroplasty. 2016.
@article{9d81770a8ba54aa5a8f642bd836213b8,
title = "Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?",
abstract = "Background: A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Methods: Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Results: Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. Conclusion: The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph.",
keywords = "Alignment, Imaging, Rotation, Slope, Tibia, Total knee arthroplasty",
author = "Schwartz, {Adam J.} and Bheeshma Ravi and Kransdorf, {Mark J.} and Clarke, {Henry D.}",
year = "2016",
month = "7",
day = "15",
doi = "10.1016/j.arth.2017.02.001",
language = "English (US)",
journal = "Journal of Arthroplasty",
issn = "0883-5403",
publisher = "Churchill Livingstone",

}

TY - JOUR

T1 - Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?

AU - Schwartz, Adam J.

AU - Ravi, Bheeshma

AU - Kransdorf, Mark J.

AU - Clarke, Henry D.

PY - 2016/7/15

Y1 - 2016/7/15

N2 - Background: A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Methods: Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Results: Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. Conclusion: The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph.

AB - Background: A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Methods: Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Results: Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. Conclusion: The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph.

KW - Alignment

KW - Imaging

KW - Rotation

KW - Slope

KW - Tibia

KW - Total knee arthroplasty

UR - http://www.scopus.com/inward/record.url?scp=85014111514&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85014111514&partnerID=8YFLogxK

U2 - 10.1016/j.arth.2017.02.001

DO - 10.1016/j.arth.2017.02.001

M3 - Article

C2 - 28259491

AN - SCOPUS:85014111514

JO - Journal of Arthroplasty

JF - Journal of Arthroplasty

SN - 0883-5403

ER -