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 stage II PTTD flatfoot compared with that in a healthy
foot. The navicular position difference relative to the talus in
the talonavicular joint was 3° more everted (p = 0.012), 1.3 mm more
lateral (p = 0.024), 0.8 mm more anterior (p = 0.037) and 2.1 mm
more proximal (p = 0.017). The cuboid position difference relative
to the calcaneus in the calcaneocuboid joint did not change significantly
in rotation and translation (all p ≥ 0.08). . Conclusion. Referring to a previous study regarding both the cadaveric foot
and the live foot, joint instability occurred in the hindfoot in
simulated weight-bearing condition in patients with stage II PTTD
flatfoot. The method used in this study might be applied to clinical
analysis of the aetiology and evolution of PTTD flatfoot, and may
inform biomechanical analyses of the effects of
The Manchester–Oxford Foot Questionnaire (MOXFQ) is a validated
16-item, patient-reported outcome measure for evaluating outcomes
of foot or ankle surgery. The original development of the instrument
identified three domains. This present study examined whether the
three domains could legitimately be summed to provide a single summary
index score. The MOXFQ and Short-Form (SF)-36 were administered to 671 patients
before surgery of the foot or ankle. Data from the three domains
of the MOXFQ (pain, walking/standing and social interaction) were
subjected to higher order factor analysis. Reliability and validity
of the summary index score was assessed.Objectives
Methods