An orthopedic device includes a patient-specific alignment guide operable for preparing a bone of a patient for resection during joint arthroplasty. The alignment guide includes a patient-specific bone engagement surface complementary to a surface of the bone of the patient and imaged from a bone scan of the patient. The alignment guide includes a plurality of guiding bores, and a plurality of alignment pins received through corresponding guiding bores for attaching the alignment guide to the bone. The alignment pins are resorbable and can be cut off during a resection of the bone.