Fatigue characteristics and biocompatability of a totally implantable bone growth stimulator in ponies.

The research study is an exploration of the fatigue characteristics and biocompatibility of a totally implantable bone growth stimulator in ponies over a period of six months.

Study Design and Methodology

The main objective of this study was to evaluate the fatigue characteristics and gross biocompatibility of an implantable bone growth stimulator (BGS) in ponies. The research involved a six-month trial with six ponies participating. In this trial, each pony had a BGS inserted in both forelegs. One key distinction to note is that the BGS in the right leg had its cathode and cathode lead preconnected by the manufacturer while the BGS in the left leg was connected during the surgical procedure.

• The evaluation was carried out through radiographic and clinical examinations at the onset and termination of the experimentation period.

Findings of the Study

At the end of the six-month experimental period, the research study found that:

• 50% (6 out of 12) of the cathode leads were broken
• 58% (7 out of 12) of the cathodes were broken
• All of the preconnected cathode and insulated cathode leads were still connected at the titanium connector socket
• Approximately a third (33.3%) of the cathodes and insulated cathode leads connected during surgery were also still successfully connected at the titanium connector socket

Implications of the Findings

The results from this study suggest that the BGS may exhibit wire fatigue more than 50% of the time when used in the lower extremity of a horse. This could mean that the device might not be as reliable or long-lasting as required for effective bone growth stimulation in these animals. The problem seems to be more evident for the BGS units that were not preconnected by the manufacturer, indicating a possible issue with the surgical procedure itself or post-surgery movements of the ponies. Therefore, these findings are useful in improving the design, implantation procedures and animal care post-implantation to ensure better performance of the BGS. The study did not mention any biocompatibility issues, so it seems that the implantable device was well-accepted by the ponies from a biological perspective.