In vitro evaluation of four methods of attaching transfixation pins into a fiberglass cast for use in horses.
OBJECTIVE
To compare the axial stability provided by 4 methods of attaching transfixation pins into a fiberglass cast.


METHODS
Axial stability of 4 methods of transfixation pin attachment to a fiberglass cast cylinder was determined in vitro. Methods of attachment included simple incorporation of the pins into the cast, placement of a washer and nut on the pin and incorporation into the cast, extension of pins beyond the cast and attachment to a steel halo, and washers within the cast and attachment to a steel halo.


METHODS
A model was designed to simulate a transfixation cast applied to the equine metacarpus. 8 identical constructs were present in each of the 4 groups. 6 fiberglass cylinders were also tested to identify the contribution of the cast cylinder to the overall stability of the transfixation cast.


METHODS
Load-sufficient curves were recorded, and a stiffness modulus was calculated for each treatment group and for a simple fiberglass cylinder without transfixation pins.


CONCLUSIONS
There was no significant difference among the 4 methods of attachment. The fiberglass cast material appears to be the major determinant of axial stability.
McClure
S R
SR
Department of Large Animal Medicine and Surgery, Texas A&M University, College Station 77843-4475, USA.
Watkins
J P
JP
Hogan
H A
HA
D000818:Animals; D002370:Casts, Surgical / Q000662:veterinary*; D004867:Equipment Design; D016267:External Fixators / Q000662:veterinary*; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary*; D005898:Glass; D006734:Horse Diseases; D006736:Horses
C009753:fiberglass