Abstract
Introduction: Precise calibration of digital radiographs is a crucial factor in making accurate measurements for preoperative planning and postoperative assessment of osseous morphology. The objective of this study was to assess the repeatability of linear measurements obtained from sequential, digital radiographic images acquired at four different timepoints in dogs that had undergone an uncomplicated tibial plateau leveling osteotomy (TPLO). Our hypothesis was that there would be minor variations in fibular length measured at different times in individual dogs, but those discrepancies would not be significant within or between observers.
Materials and Methods: Preoperative, immediate postoperative, 1- and 3-month postoperative radiographs of 30 dogs that had undergone a TPLO were obtained to measure fibular length. Three observers assessed fibular length in each radiograph and repeated the measurement at least 30 days after the initial assessment to assess inter- and intra-observer variability.
Results: The overall fibular length measured on the preoperative radiographs as determined by all observers was 199.3 and 191.4 mm on two different image viewing software applications. Variation in fibular length measured on the initial postoperative, 1 and 3 month postoperative radiographs ranged from 1.0 to 2.6%. There were no differences within observers or between the three observers (p > 0.41) with total inter- and intra-observer variability of <1%.
Discussion/Conclusion: Radiographic measurements of fibular length were consistent with small variations between time points and operators. Variation between time points is likely due to differences in marker placement relative to the fibula and resultant magnification error.
Acknowledgements: There was no proprietary interest or funding for this project.
