1. A computer implemented method for determining the 3-dimensional shape of a medical device, the method comprising: obtaining a computer readable image including a defective portion and a non-defective portion of tissue in a subject; rendering from the image data a computer-generated 3-dimensional representation of the defective portion and the non-defective portion of the tissue; identifying anatomical landmarks on the computer-generated 3-dimensional representation of the defective portion and the non-defective portion of the tissue; superimposing on the computer-generated 3-dimensional representation of the defective portion and the non-defective portion of the tissue a template to span the defective portion; deforming the template to match the anatomical landmarks; and determining the 3-dimensional shape of the medical device based on the template that spans the defective portion.