Assessment of the symmetry of bone strains in the proximal femoral medial cortex under load in bilateral pairs of cadaver femurs.

Abstract

In past studies, it has been assumed that contralateral femurs from the same patient have sufficiently symmetric mechanical properties that one femur could reliably serve as representative of the other in mechanical testing experiments dealing with surface bone strains. To assess the accuracy of this assumption, 10 pairs of cadaveric femurs without evidence of osseous abnormalities were instrumented with strain gauges on the periosteal and endosteal surfaces of the proximal medial cortex and strain measurements were made under simulated conditions of single-leg stance and stairclimbing. Although the strains in femurs from different individuals varied greatly, the degree of symmetry in the strains of contralateral femurs was high. These findings add support to the use of contralateral femurs without discernible abnormalities as suitable controls for each other in such situations.