2025 ISAKOS Biennial Congress ePoster
The Dejour Classification for Trochlear Dysplasia: Are We Speaking the Same Language?
Juan Pablo Martinez-Cano, MD, MSc, PhD, Cali, Valle del Cauca COLOMBIA
Betina B. Hinckel, MD, PhD, Troy, MI UNITED STATES
Alejandro Gallego, MD, Jamundí, Valle del Cauca COLOMBIA
Maria Tuca, MD, Santiago CHILE
Fundación Valle del Lili, Cali, Valle, COLOMBIA
FDA Status Not Applicable
Summary
The Dejour classification for trochlear dysplasia: shows slight interobserver and substantial intraobserver reliability.
ePosters will be available shortly before Congress
Abstract
Background
and Purpose
Trochlear dysplasia is one of the principal risk factors for recurrent patellar dislocation. The Dejour classification includes four categories to classify trochlear dysplasia. It is important to know how reliable is a classification between observers. The objective of this study is to evaluate the inter- and intraobserver reliability of the Dejour classification for trochlear dysplasia.
Methods
Cross-sectional, reliability study. Twenty-eight examiners from the International Patellofemoral Study Group (IPSG) 2022 meeting evaluated lateral radiographs of the knee and axial magnetic resonance images from 15 cases of patients with patellofemoral instability that had trochlear dysplasia. Each observer classified each case according to Dejour's classification for trochlear dysplasia (A–D). There were three rounds: one with only computed radiograph (CR), one with only magnetic resonance imaging (MRI) and one with both. Inter- and intraobserver reliability were calculated using kappa coefficient (0–1). Kappa interpretation was as follows: 0–0.2 = slight; 0.21–0.4 = fair; 0.41–0.6 = moderate; 0.61–0.8 = substantial; and 0.81–1 = almost perfect.
Results
The mean age of patients was: 14.6 years; 60% were female and 53% had open physis. The interobserver reliability kappa probabilities were 0.2 (CR), 0.13 (MRI) and 0.12 (CR and MRI). The intraobserver reliability kappa probabilities were 0.45 (CR), 0.44 (MRI) and 0.65 (CR and MRI).
Conclusion
The Dejour classification for trochlear dysplasia showed to have slight interobserver reliability and substantial intraobserver reliability among a group of highly interested orthopaedic surgeons in the patellofemoral joint. This suggests that raters have substantial chances of been consistent with themselves when using both radiographs and magnetic resonance imaging for evaluating trochlear dysplasia, while there is a different way of understanding the classification between them. Further effort should be directed to improve the way in which the imaging signs of trochlear dysplasia and the Dejour classification are understood by the medical community.