Do long leg supine CT scanograms correlate with weight-bearing full-length radiographs to measure lower limb coronal alignment?

Porteous, A. J.; White, P.; Gbejuade, H. O.; White, Paul; Hassaballa, M.; Porteous, A .J .; Robinson, J. R.; Murray, J. R.

Abstract

Introduction: The gold standard for measuring knee alignment is the lower limb mechanical axis (MA) using weight-bearing lower limb full-length x-ray (FLX). However, CT scanograms (CTS) are becoming increasingly popular in view of lower radiation exposure, speed of data acquisition and supine positioning. We compared the correlation and degree of agreement of knee joint coronal alignment using these two imaging modalities. Method: From our series of complex primary and revision knee arthroplasty patients, we selected those with both FLX and CTS recorded onto digital PACS. The coronal alignments were assessed in 24 knees and the valgus/varus angles relative to the MA were measured. Results were analysed statistically using the paired samples t-test, Pearson's correlation coefficient, intra-class correlation coefficient, Cohen's kappa and Passing and Bablok regression to assess potential equality of methods. Results: The mean MA was 180.5° (165°-200°) for the CTS and 181° (164°-202°) for the FLX. The CTS MA angle data between the assessors were highly correlated (r=0.971, p

• Journal Article Type: Article
• Publication Date: Jan 1, 2014
• Journal: Knee
• Print ISSN: 0968-0160
• Electronic ISSN: 1873-5800
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 21
• Issue: 2
• Pages: 549-552
• DOI: https://doi.org/10.1016/j.knee.2013.05.009
• Keywords: knee, alignment, CT scanogram, X-ray
• Public URL: https://uwe-repository.worktribe.com/output/820732
• Publisher URL: http://dx.doi.org/10.1016/j.knee.2013.05.009
• Additional Information: Additional Information : Available online before print 9 July 2013.