A patient-specific alignment guide includes a patient-specific portion and a guiding element having a through opening. The patient-specific portion has a patient-specific surface preoperatively configured to mate as a negative of a portion of an iliac crest of a pelvis of a specific patient and mate to the iliac crest only in one position. The guiding element has a preoperatively configured orientation and location relative to the patient-specific portion for preparing a bore in the bone of the patient to direct a bone screw at the preoperatively configured orientation and location for sacroiliac fixation.