Fig. 7

Biomechanical torsional test to failure results of native and drilled metacarpal and metatarsal bones (a-d). a shows the torsional stiffness of the native and drilled metacarpal (MCn vs. MCd) and metatarsal (MTn vs. MTd) bones without a statistical significant difference. b shows the result of the maximum torsional moment until failure (Mmax) for the native and drilled metacarpal and metatarsal bones. The dashed line refers to the calculated maximal torsion moment of 6.75 Nm acting during a normal gait cycle (moments gait cycle = 0.0027 body weight per meter × 85 kg body weight sheep x safety factor 3). The Mmax for the drilled MT bones was significantly lower (p = 0.023) in comparison to the native MT bones, but within the same range as the native and drilled MC bones. c shows a statistical significant lower angle at Mmax (p = 0.016) for the drilled MT bones in comparison to the native MT bones. d shows a significant lower energy to failure (p = 0.014) of the drilled MT bones in comparison to the native MT bones