abs: Comparison of Fetlock Tension Band Techniques
_{Large Animal Residents' Forum}

No studies to date have evaluated the stability and mechanical properties of a novel iso-elastic nonmetallic polymer cable (NMPC) in equine surgery. The study’s objectives were to compare the in vitro biomechanical properties of a NMPC to the traditional stainless-steel cerclage cable (SSC) in an equine metacarpophalangeal joint arthrodesis model lacking a dorsal plate application under both cyclic fatigue testing and static loading in axial compression. Five MCP joint pairs were collected from adult Thoroughbred horses, euthanized for reasons unrelated to orthopedic disease. The constructs were placed in a load cell and compared over the course of a non-destructive cyclic loading protocol followed by single cycle to failure. In cyclic testing, constructs consisting of the NMPC appeared to have a significant amount of movement between the set loads of 50N and 200N when compared to the SSC constructs. In single cycle testing, the maximum load achieved at failure in the NMPC constructs was significantly lower compared to the SCC constructs. All SSC constructs failed in a similar fashion with the cable breaking after achievement of maximum load. No NMPC broke but all cables lengthened at least 1 cm compared to the starting length. Limitations of this study include the use of cadaver limbs and a small sample size. The results of this study do not support the use of a NMPC as a palmar/plantar tension band for MCP joint arthrodesis in horses suffering from a suspensory breakdown injury because of the cable’s elastic properties.