Presentation description

Pes planovalgus (PPV) is a foot deformity characterized by a flattening of the arch and medial subluxation of the talus. Individuals with PPV have intricate morphologies with complex articular relationships, often causing pain, malalignment, and loss of function. PPV is more prevalent among high BMI patients, as increased weight places higher stress on the medial longitudinal arch, causing it to flatten. This study aimed to investigate several common 2D clinical measures of PPV between groups with varying BMIs to check for statistical significance. In this study, 74 patients presenting with PPV underwent weight-bearing CT(WBCT) scans with IRB approval. Using two-dimensional digitally reconstructed radiographs from Disior, comparisons were made across relevant clinical values determined from literature. Those consisted of Talonavicular Coverage (TNC), Meary's Angle (MA, sagittal), Calcaneal Inclination Angle (CIA), and Hindfoot Moment Arm (HMA). Parametric values (MA and CIA) were analyzed via a one-way ANOVA. Non-parametric values (HMA and TNC) were analyzed via a Kruskal Wallis test. The only statistically different clinical measure was HMA. However, it was visually apparent that the morphologies varied with BMI, suggesting that 2D measurements may not be the most accurate representation of complex foot anatomy. Most current knowledge of ankle kinematics comes from 2D measurements like these. However, WBCT scans allow for 3D analyses of bone morphology that more accurately represent complex deformities. Going forward, segmentation of these patients' WBCT scans can be used to develop 3D bone reconstructions. These can then be converted to statistical shape models, which allows for 3D analysis of morphological variations across a population of bones. This information could improve the diagnosis and treatment of pathological feet, thus improving quality of care. In this case, having an enhanced understanding of 3D morphology could reveal more information about the impact of BMI on PPV morphology, influencing clinical decisions such as preventative care and surgery.