Increase in posterior tibial slope would result in correction loss in frontal plane after medial open-wedge high tibial osteotomy

Abstract

Purpose The purpose of this study was to clarify the causes of the increase in the posterior tibial slope during open-wedge high tibial osteotomy (HTO) and to investigate whether its changes influenced the correction angle in frontal plane. Methods We retrospectively reviewed 20 patients (26 knees) treated with open-wedge HTO. They were divided into the following two groups. Group A consisted of the knees whose opening gaps were fixed using a spacer plate having the trapezoidal block with a 2°posterior slope. In Group B, anterior and posterior opening gaps were fixed separately. The posterior tibial slope and the hip-kneeankle angle were measured based on CT data. The relationship between the correction rate in frontal plane and the changes of posterior tibial slope was investigated. Results Increase in the posterior tibial slope was 2.1 ± 2.5°in Group A and 0.2 ± 1.2°in Group B, which showed a statistical difference (P = 0.02). The difference between the hip-knee-ankle angles before and after operation was 5.2 ± 2.3°in Group A and 5.5 ± 2.5°in Group B. The correction rate was statistically correlated with the changes of posterior tibial slope (R =-0.55, P = 0.003). Conclusion To avoid increase in the posterior tibial slope, the trapezoidal block with a only 2°posterior slope in a spacer plate was not sufficient, and it was necessary to fix anterior and posterior gaps separately. The correction angle in frontal plane had a trade-off relationship with the changes in posterior tibial slope. Thus, we thought that increase in the posterior tibial slope might result in correction loss. Level of evidence Therapeutic study, Retrospective comparative study, Level III.

Comparative analysis of osteotomy accuracy between the conventional and devised technique using a protective cutting system in medial open-wedge high tibial osteotomy

“…OWHTO offers numerous advantages over lateral closing wedge procedures and is gaining popularity [19][20][21]. Despite these advantages, OWHTO is associated with potential intraoperative complications: tibial plateau fractures [5], unwanted increase of the posterior tibial slope, under-or overcorrection [7][8][9], and dislocation of the osteotomy hinge [3] leading to unpredictable correction [1].…”

Leg length change after opening wedge and closing wedge high tibial osteotomy: A meta-analysis

“…Even in opening wedge HTO, the shifting weight-bearing force from medial to lateral compartment could offset the effect of tibial lengthening after opening wedge HTO,[11] especially in cases with severe soft tissue laxity on the lateral side, because weight-bearing force can lead to overcorrection of alignment despite preoperative planning, which can shorten the leg length more than required for adequate correction. In addition, the increment of posterior slope after opening wedge HTO reduces the leg lengthening effect of opening wedge HTO, because the increased posterior slope leads to anterior translation of the tibia,[16] which could decrease the magnitude of leg lengthening effect in open wedge HTO.…”

Comparative Study of Opening-Wedge High Tibial Osteotomy With and Without a Combined Computed Tomography–Based and Image-Free Navigation System

“…Moreover, Rodner et al 15 advocated that increased TPS in anterior cruciate ligamentedeficient knees treated with OWHTO redistributes pressure onto the posterior tibial plateau and suggested that this undesired redistribution of contact pressure may increase the rates of degeneration and disability. Furthermore, Asada et al 41 compared a trapezoidal block with separate fixation in the anterior and posterior opening gaps to maintain the TPS, and concluded that it was necessary for the anterior and posterior gaps to be fixed separately to maintain the TPS. Regarding the location of wedges in the osteotomy gap, Hernigou et al 7 reported that the bone wedges should be grafted in the most posterior region of the opened osteotomy site to avoid correction loss and increase the TPS.…”

“…Moreover, an internally rotated direction of the tibia might result in further undercorrection or overcorrection in the coronal plane. Regarding the relation between the coronal correction angle and change in TPS after OWHTO, Asada et al 41 reported that the correction rate was correlated with the change in TPS and that an increased TPS might result in correction loss in the coronal plane. This finding means that the adjustment of coronal alignment is closely related to the intraoperative control of TPS.…”