Failure mode and bending moment of canine pancarpal arthrodesis constructs stabilized with two different implant systems.
OBJECTIVE
To compare failure mode and bending moment of a canine pancarpal arthrodesis construct using either a 2.7 mm/3.5 mm hybrid dynamic compression plate (HDCP) or a 3.5 mm dynamic compression plate (DCP).


METHODS
Paired in vitro biomechanical testing of canine pancarpal arthrodesis constructs stabilized with either a 2.7/3.5 HDCP or 3.5 DCP.


METHODS
Paired cadaveric canine antebrachii (n=5).


METHODS
Pancarpal arthrodesis constructs were loaded to failure (point of maximum load) in 4-point bending using a materials-testing machine. Using this point of failure, bending moments were calculated from system variables for each construct and the 2 plating systems compared using a paired t-test. To examine the relationship between metacarpal diameter and screw diameter failure loads, linear regression was used and Pearson' correlation coefficient was calculated. Significance was set at P<.05.


RESULTS
HDCP failed at higher loads than DCP for 9 of 10 constructs. The absolute difference in failure rates between the 2 plates was 0.552+/-0.182 N m, P=.0144 (95% confidence interval: -0.58 to 1.68). This is an 8.1% mean difference in bending strength. There was a significant linear correlation r=0.74 (P-slope=.014) and 0.8 (P-slope=.006) between metacarpal diameter and failure loads for the HDCP and 3.5 DCP, respectively.


CONCLUSIONS
There was a small but significant difference between bending moment at failure between 2.7/3.5 HDCP and 3.5 DCP constructs; however, the difference may not be clinically evident in all patients.


CONCLUSIONS
The 2.7/3.5 HDCP has physical and mechanical properties making it a more desirable plate for pancarpal arthrodesis.
Wininger
Fred A
FA
Department of Clinical Studies-PHL, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Kapatkin
Amy S
AS
Radin
Alex
A
Shofer
Frances S
FS
Smith
Gail K
GK
D000818:Animals; D001174:Arthrodesis / Q000295:instrumentation / Q000379:methods / Q000592:standards / Q000662:veterinary; D001860:Bone Plates / Q000592:standards / Q000662:veterinary*; D001863:Bone Screws / Q000592:standards / Q000662:veterinary*; D002102:Cadaver; D019245:Compressive Strength; D004285:Dogs / Q000293:injuries / Q000601:surgery*; D004867:Equipment Design; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary*; D016268:Internal Fixators / Q000592:standards / Q000662:veterinary*; D008422:Materials Testing / Q000379:methods / Q000592:standards / Q000662:veterinary*; D013314:Stress, Mechanical; D014102:Torsion Abnormality