A computer assisted approach for monitoring and planning biological reconstructions in orthopaedic oncology: preliminary results and future perspectives.

The evaluation of the mechanical strength of a reconstructed bone, and its evolution during the follow-up is, at present, almost impossible. This information, however, may prove extremely useful in clinical practice, both in the surgical planning and in the management of the rehabilitation therapy. In this work, a non-invasive technique, based on the use of finite element modelling, is presented that allows the simulation of the mechanical behaviour of a skeletal reconstructions starting from Computed Tomography data. This method was applied to study the evolution, during the first year of follow-up, of the strength of the reconstructed femur of a ten year-old child if a short, slow, level walk were allowed. The preliminary results indicate that the window sculpted by the surgeon to allow the anastomosis of the vascular pedicle acts as a stress concentrator and that the reduced bone mineral density, induced in the child's bone by the absence of load during the post-operative period, increases the stress level in the proximal femur.