1. A method of manufacturing an arthroplasty cutting guide, the method comprising: a) obtaining images of a patient joint bone selected for an arthroplasty procedure that were generated by a medical imaging machine; b) transferring the images to a computer; c) using the computer to define first contour lines along a target region in the images corresponding to a portion of the patient joint bone to undergo the arthroplasty procedure, the first contour lines extending along contours of an outer cartilage surface in an articular area of the target region; d) using the computer to define from the first contour lines a mating region of the arthroplasty cutting guide and to convert the mating region into first production file data; e) using the computer to define second contour lines along the target region, the second contour lines extending along contours of an outer cortical bone surface in the articular area of the target region; f) using the computer to define from the second contour lines a resection plane of the arthroplasty cutting guide and to convert the resection plane into second production file data; g) using the computer to positionally coordinate the first production file data and the second production file data with respect to each other; and h) transferring the positionally coordinated first production file data and second production file data to an automated manufacturing machine that uses the positionally coordinated first production file data and second production file data to manufacture the arthroplasty cutting guide to have the mating region and the resection plane.