The Relationship Between Angular Osteologic and Radiographic Measurements of the Human Talus and Calcaneus

Background: Radiographic imaging of the foot is commonly performed when medical evaluation is indicated. Angular measurements between bones may be assessed as part of the examination for trauma and foot biomechanics. However, angular relationships between surfaces of the physical bone as they compare with the bone's radiographic image has had limited investigation. Methods: For this study, 54 human feet from amputated limbs were imaged in standard radiographic views and skeletonized. Selected angular measurements were taken on each skeletonized talus and calcaneus and were compared with those taken from radiographic images using paired Student t tests and linear regression analysis. Results: Transverse plane measurements of the talus were not significantly different (P >= .05), associating strongly (r(2) = 0.67-0.75; all P < .001). Most transverse and sagittal plane measurements of the calcaneus were not significantly different (P > .05), with transverse plane measurements more strongly associated (r(2) = 0.70-0.77; all P < .001) than sagittal plane measurements (r(2) = 0.35-0.78; all P < .001). Conclusions: Selected angular measurements of the talus and calcaneus taken from radiographic images can be compared quantitatively with the physical bone, demonstrating that angular measurements from radiographic images provide useful information concerning both of these bones. This knowledge can be applied to the understanding of the morphology of the calcaneus and talus as it relates to human foot biomechanics and should also be of use in the interpretation of the human fossil pedal record.