Lunotriquetral ligament properties: a comparison of three anatomic subregions.
The physical attributes of 3 subregions of the lunotriquetral ligament were tested in a computer-controlled multiaxis testing machine using 12 specimens. This allowed measurement of forces, moments, and displacements when ligaments were subjected to distraction, dorsopalmar translation, proximal-distal translation with a 20 N limit, and rotation with a 0.5 Nm limit. After an intact test run, selected subregions were cut randomly. Together with an additional 12 bone-ligament-bone complexes, specimens were tested to failure with servohydraulic load at 5 mm/s. The palmar subregion was thickest (2.3 +/- 0.3 mm), the dorsal and proximal progressively less. Intact rotational displacement was 35 degrees +/- 5.1 degrees, dorsopalmar displacement was 1.6 +/- 0.4 mm and 1.2 +/- 0.5 mm, respectively, proximal-distal displacement was 1.8 +/- 0.5 mm and 1.3 +/- 0.5 mm, respectively, and distractional displacement was 0.3 +/- 0.1 mm. The dorsal subregion provided 62.3% +/- 27.1% of the rotational resistance. The palmar subregion resisted 67.3% +/- 14.1% of palmar translation, while with dorsal translation both regions resisted equally. Rotational displacement increased 15.3 degrees +/- 5.6 degrees after dorsal subregion sectioning. The palmar component failure force was 301 +/- 36 N; the dorsal, 121 +/- 42 N; and the proximal, 64 +/- 14 N.
Ritt
M J
MJ
Department of Orthopedics and Biomechanics Laboratory, Mayo Clinic and Mayo Foundation, Rochester, MN, USA.
Bishop
A T
AT
Berger
R A
RA
Linscheid
R L
RL
Berglund
L J
LJ
An
K N
KN
D001696:Biomechanical Phenomena; D002102:Cadaver; D002348:Carpal Bones / Q000502:physiology; D006801:Humans; D008023:Ligaments, Articular / Q000502:physiology; D014955:Wrist Joint