Method of designing and manufacturing a human joint prosthesis

A method for making a prosthesis for a human joint bone comprising the steps of:

• a. determining the average anatomical three-dimensional shapes of both the outer contour and the cortical canal of said bone by taking a sampling of a statistically significant number of actual bones, digitizing their three-dimensional shapes, correlating them proportionally as to overall size, and averaging them;
• b. storing said digitized average shapes;
• c. determining the external and internal dimensions of the patient's corresponding bone by radiograph on at least two orthogonally disposed planes parallel to the longitudinal axis of the bone;
• d. deriving a first synthesized shape by adjusting the scale of the stored average shape to conform to the scale of the patient's bone;
• e. determining the difference between the shape of the patient's bone and the first synthesized shape at the intersections between the contours of said bone on the orthogonally disposed planes and plurality of longitudinally-spaced transverse planes normal to the longitudinal axis of said bone;
• f. deriving a second synthesized shape by adjusting the first synthesized shape to conform its entire surface to the differences so determined at each respective transverse plane;
• and
• g. fabricating the prosthesis using CAD/CAM based on the second synthesized shape.