Articular Length Better Predicts Talar Dome Radius of Curvature Than Articular Width or Age in Pediatric Osteochondral Allograft Planning

Abstract

Background:

Osteochondral lesions (OCLs) of the talus involve damage to both the articular cartilage and underlying subchondral bone, which may range from compression injury to complete fragment separation. Treating large lesions may necessitate osteochondral allograft transplantation (OCA) to ensure cartilage congruence and minimize articular step-off. However, current allograft selection techniques rely largely on gross size estimation rather than precise contour matching, which may increase the risk of graft incongruity and suboptimal clinical outcomes. This study evaluates the correlations between the talar dome posteromedial (PM) and central lateral (CL) radii of curvature (ROC) with age, articular width (AW), and articular length (AL) in a young patient group to optimize graft selection and matching.

Methods:

Twenty-nine patients, aged 9-18 years, and 30 ankles were included. Magnetic resonance imaging was used to measure talar dome ROC, AW, and AL. The ROC was measured on sagittal images at the PM and CL regions, whereas AW and AL were measured on coronal and sagittal planes, respectively. Three independent reviewers assessed all measurements using Sectra PACS software. Reliability was evaluated using intraclass correlation coefficients (<0.50, poor; 0.50-0.75, moderate; 0.75-0.90, good; >0.90, excellent). Correlations (R²) between ROC with age, AW, and AL were assessed.

Results:

The mean PM ROC was 20.55 mm and CL ROC 17.20 mm. The mean AW and AL were 27.84 mm and 36.25 mm, respectively. Intraobserver reliability was good to excellent for PM ROC and AW, and moderate to excellent for CL ROC and AL. Interobserver reliability was good to excellent for PM ROC and AW, and moderate to good for CL ROC and AL. For PM ROC, R² values were 0.29 (age), 0.18 (AW), and 0.62 (AL); for CL ROC, R² values were 0.06 (age), 0.54 (AW), and 0.78 (AL).

Conclusion:

Articular length demonstrated stronger correlations with talar dome PM and CL ROCs compared with AW and age. AL may be a useful parameter for optimizing graft selection, particularly contour and size matching, in OCA.

Graphical Abstract

This is a visual representation of the abstract.