Developmental Changes in Haemophilic Knee Joint Morphology: A Geometric Morphometric Study.

Introduction: Despite the well-established lifelong impact of haemophilia on joint health, there remains a significant gap in our understanding of the developmental morphological changes that occur in the bones of haemophilic individuals. This study applied geometric morphometric measurement (GMM) to analyse age-related morphological variations in the knee joints of haemophilia patients.

Materials and methods: This retrospective study analysed 210 anteroposterior knee radiographs from 15 male haemophilia patients (ages 8-24), grouped into 8-15, 16-20, and 21-24 years. Twenty 2D bony landmarks were annotated by two raters (ICC  =  0.98). Generalized Procrustes analysis, principal component analysis, Procrustes ANOVA, and canonical variate analysis were performed. Associations with Pettersson score (PS) and Haemophilia Joint Health Score (HJHS) were examined via multivariate regression.

Results: The diversity in morphology of knee joints among the first five principal components was 83%. Procrustes ANOVA indicated significant shape differences (p < 0.001) among age groups. Furthermore, discriminant function analysis revealed the highest Mahalanobis distance (3.6212) between age group 1 and group 3, with significant differences (p < 0.001). Notable morphological alterations were identified, characterized by a medial displacement of the patella and a reduction in joint space.

Conclusion: This study revealed significant age-related morphological alterations in the knee joints of individuals with hemophilia. The position of the patella was identified as a key morphological marker, suggesting its potential utility for long-term follow-up and the development of targeted rehabilitation programs.