Evaluation of Intra- and Interobserver Variability and Repeatability of Tibial Plateau Angle Measurements with Digital Radiography Using a Novel Digital Radiographic Program
Article first published online: 3 FEB 2010
© Copyright 2010 by The American College of Veterinary Surgeons
Volume 39, Issue 2, pages 187–194, February 2010
How to Cite
UNIS, M. D., JOHNSON, A. L., GRIFFON, D. J., SCHAEFFER, D. J., RAGETLY, G. R., HOFFER, M. J. and RAGETLY, C. A. (2010), Evaluation of Intra- and Interobserver Variability and Repeatability of Tibial Plateau Angle Measurements with Digital Radiography Using a Novel Digital Radiographic Program. Veterinary Surgery, 39: 187–194. doi: 10.1111/j.1532-950X.2009.00641.x
- Issue published online: 3 FEB 2010
- Article first published online: 3 FEB 2010
- Submitted November 2008; Accepted March 2009
Objective— To compare the intra- and interobserver variability occurring when observers with differing experience levels measure tibial plateau angles (TPAs) with a novel digital radiographic projection program (tibial plateau leveling osteotomy [TPLO] planning program), the Kodak Picture Archiving and Communications System (PACS), and standard sized printed films (SF).
Study Design— Cross-sectional study.
Sample Population— Dogs (n=36) with cranial cruciate ligament (CCL) rupture that had a TPLO.
Methods— Six observers, divided into 3 equal groups based on experience level, measured TPA on 36 digitally captured radiographic images of tibiae of dogs clinically affected with CCL rupture. Each observer used 3 methods of measuring TPA and repeated the measurements 3 times with each method. The intra- and interobserver variability was compared using the coefficient of variation.
Results— Averaged over all replications and images, there was no significant difference (P>.05) in the average variability occurring with each method for all but 1 observer. There was no effect of experience level on measurement variability; however, interobserver variability was significantly less with measurements made with the PACS and TPLO planning program compared with measurements made from SF (P<.05).
Conclusions— Repeated measurements of TPA made using digital images and computer-based measurement programs were significantly less variable between observers than those made from images printed on standard radiographic films.
Clinical Relevance— Digital radiography and computer-based measurement programs are effective for determining the TPA, allowing less variability in measurements compared with SF. The ability to manipulate the image may allow better identification of anatomic landmarks.