Determination of mechanical properties of canine carpal ligaments.

OBJECTIVE: To evaluate the mechanical properties of canine carpal ligaments for use in a finite element model of the canine antebrachium. SAMPLE POPULATION: 26 forelimbs obtained from cadavers of 13 dogs euthanized for reasons unrelated to this study. PROCEDURES: 6 ligaments (medial collateral, lateral collateral, palmar ulnocarpal, palmar radiocarpal, accessorometacarpal-V, and accessorometacarpal-IV) were evaluated. Quasistatic tensile tests were performed on all specimens (n = 8 specimens/ligament) by use of a servohydraulic materials testing system in conjunction with a 6-df load cell. Each specimen was preconditioned for 10 cycles by applying 2% strain by use of a Haversine waveform. Tension was subsequently applied to each specimen at a strain rate of 0.5%/s until ligament failure.
RESULTS: Significant differences in modulus of elasticity were detected among the ligaments. Elastic modulus did not differ significantly between the 2 accessorometacapal ligaments, between the 2 collateral ligaments, or between the 2 palmar carpal ligaments. Ligaments were classified into 3 groups (accessorometacarpal ligaments, intra-articular ligaments, and palmar carpal ligaments), and significant differences were detected among the 3 ligament groups. The accessorometacarpal ligaments had a relatively high elastic modulus, compared with results for the other ligaments. The medial and lateral collateral ligaments had the lowest elastic modulus of any of the ligaments tested. CONCLUSIONS AND CLINICAL RELEVANCE: These results indicated a strong function-elastic modulus relationship for the 6 ligaments tested. The mechanical properties described here will be of use in creating a finite element model of the canine antebrachium.