Objective. The objective of this study was to evaluate the rotation and
translation of each joint in the hindfoot and compare the load response
in healthy feet with that in stage II posterior tibial tendon dysfunction
(PTTD) flatfoot by analysing the reconstructive three-dimensional
(3D) computed tomography (CT) image data during simulated weight-bearing. . Methods. CT scans of 15 healthy feet and 15 feet with stage II PTTD flatfoot
were taken first in a non-weight-bearing condition, followed by
a simulated full-body weight-bearing condition. The images of the
hindfoot bones were reconstructed into 3D models. The ‘twice registration’
method in three planes was used to calculate the position of the
talus relative to the calcaneus in the talocalcaneal joint, the
navicular relative to the talus in talonavicular joint, and the cuboid
relative to the calcaneus in the calcaneocuboid joint. Results. From non- to full-body-weight-bearing condition, the difference
in the talus position relative to the calcaneus in the talocalcaneal
joint was 0.6° more dorsiflexed (p = 0.032), 1.4° more everted (p
= 0.026), 0.9 mm more anterior (p = 0.031) and 1.0 mm more proximal
(p = 0.004) in
