Assessment of posterior tibial slope in adults: Insights from a prospective radiographic study

The posterior tibial slope (PTS) plays a vital role in maintaining knee stability and biomechanics, influencing ligament loading, knee motion, and surgical outcomes. Despite its clinical importance, normative PTS values for the Vietnamese population remain poorly defined. This study aims to establish population-specific reference values for the PTS in healthy adult Vietnamese individuals to support surgical planning and injury risk assessment. A prospective study was conducted involving 120 healthy Vietnamese adults (60 males and 60 females) who underwent standardized lateral knee radiographs. Baseline demographic data (age, sex, height, weight, BMI) were collected. PTS was defined as the angle between a line perpendicular to the anterior tibial cortex and the line connecting the anterior and posterior margins of the tibial plateau, with measurements performed by two blinded orthopedic surgeons to ensure reliability. Significant gender differences in the PTS were observed. Females exhibited higher mean PTS values than males on both the right (8.10° ± 1.84° vs. 7.23° ± 1.74°, p = 0.002) and left (8.11° ± 1.85° vs. 7.25° ± 1.74°, p = 0.003) knees. No significant differences in PTS were associated with BMI or height. The distribution of high and low PTS values also differed significantly by sex (p = 0.003). This study provided normative PTS data for the adult Vietnamese population, revealing notable sex-based variations. These findings underscore the importance of personalized surgical approaches and prosthetic design considerations tailored to specific demographic characteristics to optimize the clinical outcome of knee-related procedures.