Good correlation between two- and three-dimensional parameters of intercondylar notch morphology in the pediatric...

Distal femoral morphology is associated with ligamentous injuries, including anterior cruciate ligament (ACL) tears, and may influence treatment outcomes. While intercondylar notch morphology has been extensively studied in adults using different radiographic parameters, its developmental anatomy in pediatric populations remains poorly understood. The objective of this study is to describe intercondylar notch morphology in skeletally immature specimens using computed tomography (CT). We hypothesized that 1) notch height and notch width are positively correlated with age, while the notch width index (NWI) remains stable throughout growth, and 2) that commonly used two-dimensional notch measurements would show no correlation with three-dimensional notch volume.

Skeletally immature cadaveric knees were evaluated using CT. Two-dimensional measurements in the coronal plane included notch width, notch height, and notch width index (NWI). Serial axial cuts were used to calculate three-dimensional intercondylar notch volume. Spearman correlation analyses were performed to assess correlations among radiographic parameters and with demographic variables. The intraclass correlation coefficient values of two raters were good to excellent for all measurements.

The study cohort included 39 CT scans of skeletally immature cadaveric knees from 22 individuals (16 male, 6 female) with a mean age of 4.3 ± 4.4 years (range, 1 month-16 years). Correlation analysis showed that notch width and notch height were statistically significantly associated with notch volume (both p < 0.01), whereas NWI was not correlated with notch volume (p = 0.14) or notch height (p = 0.66). No statistically significant associations were found between any radiographic parameters and sex (all p > 0.5). Age was statistically significantly correlated with notch width, notch height, and notch volume (all p < 0.01), but not with NWI (p = 0.1).

The findings of this study demonstrate a good correlation between two- and three-dimensional measurements of the pediatric intercondylar notch. Therefore, preoperative assessment of notch height and width may serve as a reliable surrogate for three-dimensional notch volume, enabling surgeons to accurately prepare for ACL surgical planning. However, the NWI does not fully capture the complex three-dimensional morphology of the developing intercondylar notch. Incorporating volumetric evaluation may therefore provide important additional insights for a more comprehensive characterization of notch anatomy in the immature knee.

Level V, Descriptive laboratory study.