Abstract: A computer-implemented method of determining fixation of a prosthesis in bone matter based on bone anatomy and density information comprises generating a three-dimensional model of a bone of a patient for output in a video display unit, adding three-dimensional bone density information for the bone matter to the three-dimensional model, simulating a. preparation of the bone to produce a bone surface on the three-dimensional model, simulating placement of the prosthesis in the bone surface, estimating a fixation strength of the prosthesis to the bone matter using the bone density information at the prosthesis, and outputting indicia on the video display unit that indicates risk factors for displacement, of the prosthesis from the bone matter.

Abstract: A copyholding device is disclosed of the type having a generally flat, rectangular base assembly intended to underly an associated typewriter or the like; the base assembly operatively supports the lower end of an upright pivotable support column, the upper end of which carries an easel-like support platform which functions to carry worksheets or the like that are to be copied with the typewriter.