Effect of preservation medium on the mechanical properties of cat bones.

Mechanical properties of long cat bones after freezing at -20 degrees C and after storage in 10 percent buffered formalin were investigated. The right humeri and femora from 48 adult cats were divided into four groups: Groups 1 and 2 were stored in a freezer at -20 degrees C for 3 and 21 days, respectively, while Groups 3 and 4 were stored in 10 percent buffered formalin for 3 and 21 days, respectively. The control left bones were tested fresh. The humeri were subjected to a torsion test and the femora to a four-point bending test. Freezing had no effect on the mechanical properties evaluated, while formalin storage caused a 50 percent reduction in energy absorption and increased the brittleness of the bones.