Patient-specific guides are used in high-cost procedures; however, these guides also can be used to aid in other procedures, such as opening-wedge valgus-producing high tibial osteotomy. The use of patient-specific guides to make bone cuts and correctly place an implant may be beneficial for bone surgery. This video shows the steps and software (mostly free) necessary for the three-dimensional surgical planning of a valgus-producing osteotomy and how to design your own patient-specific guide for the procedure.