[Bending and torsion stability of healed metatarsus osteotomy after plate osteosynthesis]

72 transversal osteotomies on metatarsus of sheep were stabilized under contact or gap conditions with three different thicknesses of bone plates. After 16 weeks we measured bending or torsion break loading, moment of inertia of bone by transmission methode and calculated moments of bending and torsion strength.

ultimate bending strength on osteotomied bone 100.4 +/- 14.4 N/mm2 under contact, and 77.4 +/- 11.4 N/mm2 under gap condition, torsion bending strength 26.1 +/- 4.9 N/mm2 under contact, and under gap condition 21.5 +/- 4.3 N/mm2. The best results were given by the 2.8 mm plate with the same moment of inertia like the small ASIF plate.