An osteotomy method includes attaching a patient-specific osteotomy guide to a corresponding surface of a tibia of a patient and making an osteotomy at a patient-specific orientation through a resection slot of the osteotomy guide. The osteotomy guide is removed and first and second faces of the osteotomy are opened to form an implant insertion angle. The first and second faces of the osteotomy are secured at the implant insertion angle and an osteotomy implant having a patient-specific wedge angle that is smaller than the implant insertion angle is implanted. The first and second faces of the osteotomy are brought to the patient-specific wedge angle and in contact with the osteotomy implant.