Nitinol is a biomaterial with a remarkable shape memory property, which may show promise for orthopaedic applications. A stiffness-alterable implant may enhance fracture healing. Custom-designed Nitinol fracture-fixation plates were mechanically tested to examine bending and torsional stiffness properties. Shape transformation of the plates back to their initial configurations was incomplete. The structural bending stiffness of four different designs changed before and after shape transformation by 40-60 \%. This is a considerable change in bending stiffness as a result of temperature-induced shape change. An implantable bone plate requires optimization of both design and material in further studies.