Evaluation of Tibial Slope on Radiographs in Pediatric Patients With Tibial Spine Fractures: An Age- and Sex-Matched Study

Abstract

Background: A recent study has reported that the radiographic measurement of posterior tibial slope (PTS) is larger in male pediatric patients with tibial spine fractures (TSF) than in controls. However, they found no difference in PTS between female patients and controls. Purpose: (1) To identify whether PTS is larger in female pediatric patients with TSF than in female controls and (2) to validate the relationship between PTS and pediatric TSF in male patients. Study Design: Cross-sectional study; Level of evidence, 3. Methods: After an a priori power analysis, 84 pediatric patients with TSF (50 female patients and 34 male patients) and 84 age- and sex-matched controls were enrolled in this study. Demographic information, including sex, age, and race, was recorded. Skeletal maturity was determined based on the stage of epiphyseal union on knee radiographs. PTS was defined as the angle between a line perpendicular to the longitudinal axis of the tibia and the posterior inclination of the medial tibial plateau on standard knee lateral radiographs. Results: The mean age when the TSF occurred was 11.2 ± 2.7 years for female patients and 12.9 ± 2.5 years for male patients. There was no significant difference in skeletal maturity between female patients and female controls or between male patients and male controls. The mean PTS was not significantly different between female patients (8.8°± 2.8°) and female controls (8.3°± 3.1°) ( P = .366) or between male patients (9.0°± 2.8°) and male controls (9.3°± 2.6°) ( P = .675). Those with a PTS >1 SD (2.9°) above the mean (8.8°) had no greater odds (1.0 [95% CI, 0.4-2.5]; P≥ .999) of having a TSF than others. Conclusion: PTS was not found to be a risk factor for pediatric TSF in female or male patients in this study.