A biomechanical comparison of conventional dynamic compression plates and string-of-pearls™ locking plates using cantilever bending in a canine Ilial fracture model.

BACKGROUND: Fracture of the ilium is common orthopedic injury that often requires surgical stabilization in canine patients. Of the various methods of surgical stabilization available, application of a lateral bone plate to the ilium is the most common method of fixation. Many plating options are available, each having its own advantages and disadvantages. The purpose of this study was to evaluate the biomechanical properties of a 3.5 mm String-of-Pearls™ plate and a 3.5 mm dynamic compression plate in a cadaveric canine ilial fracture model. Hemipelves were tested in cantilever bending to failure and construct stiffness, yield load, displacement at yield, ultimate load, and mode of failure were compared. RESULTS: The mean stiffness of dynamic compression plate (116 ± 47 N/mm) and String-of-Pearls™ plate (107 ± 18 N/mm) constructs, mean yield load of dynamic compression plate (793 ± 333 N) and String-of-Pearls™ plate (860 ± 207 N) constructs, mean displacement at yield of dynamic compression plate (8.6 ± 3.0 mm) and String-of-Pearls™ plate (10.2 ± 2.8 mm) constructs, and ultimate load at failure of dynamic compression plate (936 ± 320 N) and String-of-Pearls™ plate (939 ± 191 N) constructs were not significantly different. No differences were found between constructs with respect to mode of failure. CONCLUSIONS: No significant biomechanical differences were found between String-of-Pearls™ plate and dynamic compression plate constructs in this simplified cadaveric canine ilial fracture model.

A comparison of conventional compression plates and locking compression plates using cantilever bending in an ilial fracture model.

OBJECTIVES: The purpose of this study was to compare the stiffness, yield load, ultimate load at failure, displacement at failure, and mode of failure in cantilever bending of locking compression plates (LCP) and dynamic compression plates (DCP) in an acute failure ilial fracture model. Our hypothesis was that the LCP would be superior to the DCP for all of these biomechanical properties. METHODS: Ten pelves were harvested from healthy dogs euthanatized for reasons unrelated to this study and divided into two groups. A transverse osteotomy was performed and stabilized with either a 6-hole DCP applied in compression or a 6-hole LCP. Pelves were tested in cantilever bending at 20 mm/min to failure and construct stiffness, yield load, ultimate load at failure, displacement at failure, and mode of failure were compared. RESULTS: The mean stiffness of DCP constructs (193 N/mm [95% CI 121 - 264]) and of LCP constructs (224 N/mm [95% CI 152 - 295]) was not significantly different. Mean yield load of DCP constructs (900 N [95% CI 649 -1151]) and of LCP constructs (984 N [95% CI 733 -1235]) was not significantly different. No significant differences were found between the DCP and LCP constructs with respect to mode of failure, displacement at failure, or ultimate load at failure. CLINICAL SIGNIFICANCE: Our study did not demonstrate any differences between DCP and LCP construct performance in acute failure testing in vitro.