Illustration of CT-scan for CSA measurement, mechanical testing, and corresponding digital photograph of the fracture site.

<p>(A) A CT-scan image for CSA measurement. The outer circle (red) shows the outer surface of the callus, and the inner circle (green) shows the inner surface of the callus. CSA = outer circle area—inner circle area; (B) Illustration of mechanical testing by 3-point bending using the Bose (3520-AT) computerised system; (C) Typical photograph showing a single cross-section through the callus site formed after fracture from the mechanical test in (A). (D) The modelled cross section of the femoral samples. D, external diameter of samples; d, internal diameter. (E) Three-point loading. F, applied force; L, span length. # callus; * bone marrow.