Rotational stability of the carpus relative to the forearm.
To perform rotational tasks adequately, the rotational laxity between the radius and the carpus must be constrained within a certain limit. The contribution of nine individual capsuloligamentous structures to the rotational stability of the radiocarpal joint was studied using 14 fresh-frozen human cadaveric specimens. Torque-rotation curves, with sequential section of the soft-tissue structures, were used to calculate the percentage contribution of each individual structure. The primary pronation constraint was the palmar radioscaphocapitate ligament. The contributions to supination constraint were more complex; the dorsal radiotriquetral ligament was dominant, assisted by the palmar ulnolunate ligament. Structures originating from the ulna changed their major constraint contribution with forearm orientation, whereas those with a radial origin had a constant contribution independent of forearm rotation. Injury of these structures may lead to rotational instability at the radiocarpal level and should be considered when treating carpal instabilities.
Ritt
M J
MJ
Department of Orthopedics, Mayo Clinic/Mayo Foundation, Rochester, MN 55905, USA.
Stuart
P R
PR
Berglund
L J
LJ
Linscheid
R L
RL
Cooney
W P
WP
An
K N
KN
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D005542:Forearm / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007593:Joint Instability / Q000503:physiopathology; D008023:Ligaments, Articular / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011403:Pronation / Q000502:physiology; D012399:Rotation; D013484:Supination / Q000502:physiology; D014955:Wrist Joint / Q000502:physiology*