Abstract
Objective Cats rely on their forelimb mobility for everyday activities including climbing and
grooming. Supination and pronation of the forelimb in cats are considered to primarily
involve the antebrachium, rather than the carpus. Therefore, our null hypothesis was
that there would be no movement of the carpal bones (radial carpal bone, ulnar carpal
bone and accessory carpal bone) relative to the ulna during supination and pronation.
Study Design Eight feline cadaveric forelimbs were rotated from supination to pronation in a jig
and computed tomography was performed in the neutral, supinated and pronated positions.
The individual carpal bones were segmented from computed tomography images of the
supinated and pronated scans in each of the eight specimens. A feline ulna coordinate
system was established and used to quantify the translations and rotations between
bones of the proximal carpal row and antebrachium.
Results After the carpus was rotated from the initial supinated position into pronation,
there was significant translation (x, y and z axes) and rotation (x and y axes) of
the proximal row of carpal bones based on absolute magnitude values. Given the differences
in translations and rotations of the proximal row of carpal bones, our null hypothesis
was rejected.
Conclusion The proximal row of carpal bones translate and rotate independently from the ulna
in the cat during pronation of the antebrachium. This may have future implications
in the diagnosis and management of feline carpal injuries involving the antebrachiocarpal
joint.
Keywords
kinematics - feline - antebrachiocarpal joint - carpus - pronation/supination
