In vitro biomechanical study of rotational stabilizers of the canine elbow joint.
OBJECTIVE
To develop a model for measuring rotary stability of the canine elbow joint and to evaluate the relative contribution of the anconeal process (AN), lateral collateral ligament (LCL), and medial collateral ligament (MCL).


METHODS
18 forelimbs from 12 canine cadavers.


METHODS
Forelimbs were allocated to 3 experimental groups (6 forelimbs/group). Each intact forelimb was placed in extension at an angle of 135 degrees and cycled 50 times from -16 degrees (pronation) to +28 degrees (supination) in a continuous manner at 2.0 Hz. Cycling was repeated following sectioning of the structure of interest (group 1, AN; group 2, LCL; and group 3, MCL). Torque at -12 degrees (pronation) and +18 degrees (supination) was measured for each intact and experimentally sectioned limb. A Student t test was performed to compare torque values obtained from intact verses experimentally sectioned limbs and for comparison with established criteria for differentiation of primary (> or = 33%), secondary (10 to 33%), and tertiary rotational stabilizers (< 10%).


RESULTS
In pronation, the AN was the only primary stabilizer (65%). For supination, the LCL was a primary stabilizer (48%), AN was a secondary stabilizer (24%), and MCL was a tertiary stabilizer (7%).


CONCLUSIONS
With the elbow joint in extension at an angle of 135 degrees, the AN is a primary rotational stabilizer in pronation, and the LCL is a primary stabilizer in supination. Disruption of the AN or LCL may affect rotary range of motion or compromise stability of the elbow joint in dogs.
Talcott
Kent W
KW
Schulz
Kurt S
KS
Kass
Philip H
PH
Mason
David R
DR
Stover
Susan M
SM
D000818:Animals; D001696:Biomechanical Phenomena; D017885:Collateral Ligaments / Q000502:physiology; D004285:Dogs / Q000502:physiology*; D005552:Forelimb / Q000502:physiology*; D007596:Joints / Q000502:physiology*; D011403:Pronation / Q000502:physiology; D013484:Supination / Q000502:physiology