#$%^&*AU2013200861B220150625.pdf#####SYSTEM AND METHOD FOR MANUFACTURING ARTHROPLASTY JIGS HAVING IMPROVED MATING ACCURACY ABSTRACT Disclosed herein is a method of defining a mating surface in a first side of an arthroplasty jig (2). The mating surface is configured to matingly receive and contact a corresponding patient surface including at least one of a bone surface and a cartilage surface. The first side is oriented towards the patient surface when the mating surface matingly receives and contacts the patient surface. The method may include: a) identifying a contour line (210) associated with the patient surface as represented in a medical image; b) evaluating via an algorithm the adequacy of the contour line (210) for defining a portion of the mating surface associated with the contour line (210); c) modifying the contour line (210) if the contour line (210) is deemed inadequate; and d) employing the modified contour line (210) to define the portion of the mating surface associated with the contour line.