COMPARATIVE BIOMECHANICAL STABILITY OF TITANIUM BONE FIXATION SYSTEMSIN METACARPAL FRACTURES

The biomechanical properties of apex bending and torsional rigidity of 11 different titanium mini- and microplates (Leibinger and Synthes) w ere examined to evaluate the effects of plate design and thickness and screw size and design. Two hundred sixteen fresh-frozen human cadaver ic metacarpal bones underwent a midshaft transverse osteotomy followed by application of one of the following plates: Synthes 1.5-mm and 2.0 -mm five-hole linear plates; Leibinger linear 1.2-mm 5-hole, 1.7-mm 4- hole, 2.3-mm 4-hole plates; or Leibinger three-dimensional 1.2-mm 4-ho le, 1.2-mm 8-hole, 1.7-mm 4-hole, 1.7-mm 8-hole, 2.3-mm 4-hole, and 2. 3-mm 8-hole plates. The specimens were subjected to a three-point bend ing test with apex dorsal or apex volar loading or torsional loading. Analysis of variance statistical analysis revealed that increasing pla te thickness and, more significantly, three-dimensional design were as sociated with increased rigidity.