The rotational friction characteristics of human long bones

The rotational friction characteristics of unembalmed human long bones (femora and tibiae) have been determined following osteotomy (surgical sectioning). The coefficients of static and kinetic friction were determined for bones cut with a Gigli saw and an oscillating saw as well as for bones ground to a 17 μm silicon carbide finish. It was found that there was no difference in the coefficients of static and kinetic friction for both types of bone when cut by surgical saws but the coefficients obtained were greater than those for ground bones. The results suggest that bone-bone friction is a function of the type of bone, its surface finish and the degree of bone-bone interdigitation arising from the apposition force used to reduce anatomically the osteotomy.