Comparison of Different Techniques for Measuring Posterior Tibial Slope

Abstract

Objectives: The posterior tibial slope assessment is crucial in preoperative planning for various surgeries. Different measurement methods exist, but no study has compared them. This study aims to verify the equivalence of four techniques for measuring the posterior tibial slope in lateral knee radiographs and assess inter-observer reliability among evaluators with different academic training levels. Methods: Forty-three lateral knee radiographs from patients with osteoarthritis and ligament injuries who had indications for tibial osteotomy were evaluated. Three evaluators with varying levels of academic training performed measurements using four parameters: anterior cortex, posterior cortex, anatomical axis of the proximal tibia, and anatomical axis of the proximal fibula. Results were expressed as mean values ± standard deviation, and a p-value < 0.05 was considered statistically significant. Results: The average degree values were 12.6±4.4 for the anterior cortex, 10.1±3.8 for the tibial axis, 7.8±4.1 for the posterior cortex, and 11.6±4.6 for the fibular axis. There was a significant difference between all these measurements, except for the comparison between the anterior cortex and the fibular axis. In terms of the tibial axis, the evaluator with the lowest level of training showed significant variation compared to the other two evaluators. Conclusion: The four methods for measuring the posterior tibial slope are not equivalent, except for the anterior cortex and fibular axis measurements. Lower-level trained professionals had difficulty performing tibial axis measurements. Further studies are needed to determine the most accurate technique for assessing posterior tibial slope angulation