Correlation of Talar Anatomy and Subtalar Joint Alignment on Weightbearing Computed Tomography With Radiographic Flatfoot Parameters

Background:Underlying bony deformity may be related to development of adult-acquired flatfoot deformity (AAFD). Multiplanar weightbearing (MP-WB) computed tomography can be used to identify subtalar deformity which may contribute to valgus hindfoot alignment. On coronal MP-WB images, 2 angles reliably evaluate the subtalar joint axis: the angle between the inferior facet of the talus and the horizontal (inftal-hor) and the angle between the inferior and superior facets of the talus (inftal-suptal). Although these angles have been shown to differ significantly between flatfoot patients and controls, no study has investigated their relationships with other components of AAFD. We hypothesized that these angles would correlate strongly with commonly used radiographic measures of AAFD.Methods:Forty-five patients with stage II AAFD and 17 control patients underwent MP-WB imaging and standard weightbearing radiographs. MP-WB measurements were correlated with standard radiographic measurements of AAFD. Difference...