The influence of different hinge position on PTS during HTO: comparison between open-wedge and closed-wedge HTO

Abstract

Purpose The purpose of this study was to determine the significance of hinge position through comparison between open-wedge and closed-wedge high tibial osteotomy (HTO) and to determine the ideal hinge position to minimize the effect of HTO on the posterior tibial slope (PTS) and medial proximal tibial angle (MPTA). Methods Procedures were performed on 32 cadaveric knees using open-wedge HTO with the standard hinge position or a low hinge position or closed-wedge HTO with the standard hinge position or a low hinge position. To define the standard hinge position in open wedge HTO, we drew a line 3-cm inferior to the medial tibial plateau toward the fibular head and located the intersection of this line with a longitudinal line 1-cm medial to fibular shaft. The low hinge position was then defined as the point 1-cm inferior to the standard position. For the standard hinge position for closed-wedge HTO, we drew a line parallel with joint line from 2-cm inferior to the lateral tibial plateau. The low hinge position was then defined as the point 1-cm inferior to the standard position. Results For the open-wedge procedure, osteotomy through the low hinge position resulted in a significantly greater PTS compared to osteotomy through the standard hinge position. MPTA was also significantly greater for the low hinge position compared to standard hinge position. In the closed-wedge HTO, neither the PTS nor MPTA was significantly different for the low and standard hinge positions. Conclusions Hinge position significantly affects changes in the PTS and MPTA following open-wedge but not closed-wedge HTO. Understanding how to hinge position affects the PTS and MPTA is critical for surgeons performing open-wedge HTO procedures. Adopting an accurate hinge position is crucial for preventing complications, especially in open-wedge osteotomy, due to postoperative changes in the PTS and MPTA.

Effect of the sagittal osteotomy inclination angle on the posterior tibial slope change in high tibial osteotomy: three-dimensional simulation study

“…It was located approximately 1.0 cm medial to the lateral cortex and 1.5 cm below the joint surface in the coronal plane(Fig. 1 -C) 24 , 25 . The rotate tool in Mimics software was used to restore the original tibial model.…”

“…Point 2 (P2), which was used as a hinge, was located 1.0 cm medially from the lateral cortex of the tibia on the x -axis, 1.5 cm below the articular surface on the z -axis (Fig. 2 -B) 24 , 25 , 29 , and at the midpoint of the entire length of the anteroposterior articular surface on the y -axis (Fig. 2 -C).…”

High Tibial Osteotomy in Knee Reconstruction and Joint Preservation

“…28 Although these represent the average reported findings, slope changes can be markedly influenced, purposefully or inadvertently, based on the angle of the osteotomy cut and/or the location of the hinge. [29][30][31] Altering the location of the hinge can affect the effect of tibial slope. A more posterolateral position of the hinge, when cutting from an anteromedial to posterolateral direction, can lead to increased posterior tibial slope.…”

“…The location of the hinge point can be adjusted based on preoperative planning to allow for changes in the coronal plane or sagittal plane based on preoperative planning. 30 Fixation may be done with a variety of plate and screw or wedge constructs, and bone graft or void fillers may be used but are not universally required. 1,17,33 As previously noted, opening wedge osteotomies tend to increase the posterior tibial slope.…”