Radiographic evaluation and preoperative planning for high tibial osteotomies

A standard set of preoperative plain radiographs includes the following: bilateral weight-bearing anteroposterior views in full extension, bilateral weight-bearing posteroanterior tunnel views at 30 degrees flexion, lateral views, skyline views of the patellofemoral joint, and a standing single leg hip-to-ankle anteroposterior view. Using these radiographs, 3 preoperative planning methods for a valgus-producing high tibial osteotomy are presented. These methods can be based on the anatomic axis, the mechanical axis, or the weight-bearing line. Sagittal plane alignment is also considered. Both anterior and posterior cruciate ligament instability may be taken into account in the preoperative planning process through alterations in the posterior tibial slope.