A system for making a customized orthopedic surgical instrument for use in repairing a joint of a patient includes a computer system for generating computer-readable instructions to form a patient-specific orthopedic surgical instrument based at least in part on image data obtained from at least a portion of a bone corresponding to the joint of the patient； and a machine for forming a patient-specific orthopedic surgical instrument from the computer-readable instructions. The surgical instrument includes a resin composition including from about 50 wt % to about 90 wt % of a base thermoplastic and from about 10 wt % to about 50 wt % of a filler material. The base thermoplastic includes polyetherimide, polycarbonate, modified polyphenylene ether, polyamide, copolymers of these thermoplastics, and combinations thereof. The surgical instrument includes at least one surface portion having a shape that substantially conforms to a corresponding surface portion of the bone.
