Morphological analysis of ankle joint space width

This study constructed a statistical shape model (SSM) of the full ankle joint-including the tibia, talus, calcaneus, and fibula-in healthy Chinese males and analyzed the variation patterns of joint space width (JSW). Computed tomography scans of 108 asymptomatic ankle joints were collected from healthy Chinese males and used to construct a statistical shape model based on principal component analysis. Anatomical variations were evaluated using spatial mapping and least-squares regression. The statistical shape model satisfied the validation criteria for accuracy, compactness, generalization, and specificity, and participants demonstrated high conformity in joint surface coverage and congruency. The first principal component explained more than 22% of the total variance. The minimum joint space widths for the tibiotalar, talofibular, and talocalcaneal joints ranged from 0.85 to 1.95 mm, 0.87 to 2.39 mm, and 0.90 to 3.32 mm, respectively, while the average joint space widths ranged from 2.81 to 3.35 mm, 1.36 to 3.36 mm, and 2.12 to 4.95 mm, respectively. Regression analysis showed that the first five principal modes of variation were strongly correlated with anatomical variations in ankle JSW. This study will provide theoretical support for the early diagnosis and personalized treatment of ankle joint diseases, as well as important morphological references for prosthesis design and biomechanical simulation research.