In vitro evaluation of four methods of attaching transfixation pins into a fiberglass cast for use in horses.

This research aims to understand the effectiveness of four different techniques of attaching stabilization pins to a fiberglass cast which is often used for treatment purposes in horses. The study, which was conducted in a controlled laboratory setting, infers that the type of attachment method does not significantly influence the axial stability of the cast, but the cast material itself does.

Objective of the Research

• The goal of this research is to compare the axial stability provided by four distinct techniques of attaching transfixation pins into a fiberglass cast. Transfixation pins are used in veterinary orthopedic procedures to immobilize a fracture or to allow certain types of fractures to heal.

Methods

• The four methods of attachment tested in this study were: simply incorporating the pins into the cast, using a washer and nut on the pin and incorporating these into the cast, extending the pins beyond the cast and attaching them to a steel halo, and using the washers within the cast and attaching these to a steel halo.
• The study utilised a specially designed model that imitates a transfixation cast applied to the equine metacarpus, or the region of a horse’s limb that corresponds to the human hand or foot excluding the fingers or toes, to test the stability of the fixation pins.
• Each of the four groups contained eight identical constructs, and six fiberglass cylinders without transfixation pins were also tested to understand the cast material’s contribution to the overall stability of the transfixation cast.
• Through recording load-sufficient curves, a stiffness modulus was calculated for each treatment group as well as for a simple fiberglass cylinder without the pins to compare the effectiveness of each method.

Conclusions

• The research found no significant difference among the stability provided by the four different methods of pin attachment. This implies that the choice of method does not influence the outcome considerably.
• The study concluded that the fiberglass material used to make the cast is the major contributor to the axial stability of the transfixation cast rather than the technique used to attach the pins.