Editorial Commentary: Various High Tibial Osteotomy Techniques Show High Survivorship, Medial Opening-Wedge Technique Has Risks, and Patient-Specific Instrumentation Shows Promise.

Abstract

Valgus-producing high tibial osteotomy (HTO) is a treatment for medial compartment knee osteoarthritis. There has been much debate about which type of osteotomy is the "best." Many techniques, including medial opening-wedge, lateral closing-wedge, dome, and chevron-type osteotomies, have proven track records, with survival rates free of conversion to total knee replacement ranging from 85% to 93% at 8 years or more in some series. One of the main drawbacks to medial opening-wedge HTO is the effect on tibial slope and patellar height. These osteotomies tend to open more in the anterior aspect of the osteotomy, resulting in an increased posterior tibial slope. This can lead to strain on the anterior cruciate ligament, so there is interest in avoiding this in the setting of anterior cruciate ligament reconstruction. If there is a significant increase in posterior tibial slope, a "bony" flexion deformity might even occur. Another potential issue with medial opening-wedge HTO is a change in patellar height leading to patella infera, which may negatively impact the extensor mechanism and quadriceps function, lead to altered patellofemoral contact pressures, and theoretically, even cause accelerated rates of patellofemoral osteoarthritis. Patient-specific cutting guides developed with precise preoperative planning, using computed tomography, can guide everything from desired correction in 1 or multiple planes to positioning of the hinge pin. The data are so precise that the cutting jigs can determine the exact depth of the saw cut in each region of the bone, patient-specific plates can be precontoured to match the patient's bony anatomy after the osteotomy, and even the screw lengths for the plate can be determined. Initial data are quite encouraging; for example, a laboratory study has shown superior accuracy and decreased radiation exposure compared with the traditional freehand technique.