Equine Surgery Resident Louisiana State University
An Ex Vivo Comparison of Metacarpophalangeal Joint Arthrodesis Techniques in the Horse. Kadic L, Rademacher N, Liu C, Leise B, McCauley C, Riggs L. Louisiana State University, Baton Rouge, LA.
No studies to date have evaluated the stability and mechanical properties of a locking compression plate (LCP) alone compared to a combined LCP and stainless steel cable (SSC) tension band in MCP joint arthrodesis. The study’s objective was to compare the biomechanical characteristics of two arthrodesis techniques for the equine MCP joint using either a 10-hole 5.5 mm LCP alone or in combination with a 2.0 mm cable under cyclic fatigue testing and single cycle to failure in axial compression. Five MCP joint pairs were collected from adult Thoroughbred horses, euthanized for reasons unrelated to orthopedic disease. CT exams were performed to determine bone density. The constructs were placed in a load cell and compared over the course of a nondestructive cyclic loading protocol followed by single cycle to failure. In cyclic testing, construct movement did not change between the first and last 5% of testing cycles regardless of construct and overall movement of each construct during cyclic testing was less than 1.1 mm. In single cycle testing, the maximum load at failure was significantly higher in the LCP-SSC compared to constructs with the LCP alone (P = 0.0464). While no significant difference was found between the constructs during cyclic testing, LCP-SSC constructs conferred an increased stability in single cycle to failure testing. Limitations of this study include the use of cadaver limbs and a small sample size. The results of this study support an increase in stability of the construct with cable and therefore its use in clinical situations.