The main object of this study was to use a geometric morphometric
approach to quantify the left-right symmetry of talus bones. Analysis was carried out using CT scan images of 11 pairs of
intact tali. Two important geometric parameters, volume and surface
area, were quantified for left and right talus bones. The geometric
shape variations between the right and left talus bones were also
measured using deviation analysis. Furthermore, location of asymmetry
in the geometric shapes were identified. Numerical results showed that talus bones are bilaterally symmetrical
in nature, and the difference between the surface area of the left
and right talus bones was less than 7.5%. Similarly, the difference
in the volume of both bones was less than 7.5%. Results of the three-dimensional
(3D) deviation analyses demonstrated the mean deviation between
left and right talus bones were in the range of -0.74 mm to 0.62
mm. It was observed that in eight of 11 subjects, the deviation
in symmetry occurred in regions that are clinically less important
during talus surgery. Objective
Methods
Results
Overlap between the distal tibia and fibula has always been quoted
to be positive. If the value is not positive then an injury to the
syndesmosis is thought to exist. Our null hypothesis is that it
is a normal variant in the adult population. We looked at axial CT scans of the ankle in 325 patients for
the presence of overlap between the distal tibia and fibula. Where
we thought this was possible we reconstructed the images to represent
a plain film radiograph which we were able to rotate and view in
multiple planes to confirm the assessment. Objectives
Methods