Department of Orthopaedic Surgery, Faculty of Medicine, Kinki University, 377-2 Ohno-Higashi, Osaka-Sayama City, Osaka, 589-8511, Japan.
Knee Surg Sports Traumatol Arthrosc. 2012 Mar;20(3):571-8. doi: 10.1007/s00167-011-1610-1. Epub 2011 Jul 20.
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.
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-knee-ankle 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.
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).
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.
Therapeutic study, Retrospective comparative study, Level III.
本研究旨在阐明开放式胫骨高位截骨术（HTO）中后胫骨斜率增加的原因，并探讨其变化是否会影响额状面的矫正角度。
我们回顾性分析了 20 例（26 膝）接受开放式胫骨高位截骨术的患者。他们被分为以下两组。A 组的膝关节采用具有 2°后斜率的梯形块的间隔板固定开口间隙。在 B 组中，前、后开口间隙分别固定。根据 CT 数据测量后胫骨斜率和髋膝踝角。研究了额状面矫正率与后胫骨斜率变化之间的关系。
A 组后胫骨斜率增加 2.1±2.5°，B 组增加 0.2±1.2°，差异有统计学意义（P=0.02）。A 组手术前后髋膝踝角的差值为 5.2±2.3°，B 组为 5.5±2.5°。矫正率与后胫骨斜率的变化呈统计学相关（R=-0.55，P=0.003）。
为了避免后胫骨斜率增加，间隔板中的梯形块仅具有 2°的后斜率是不够的，有必要分别固定前、后间隙。额状面的矫正角度与后胫骨斜率的变化呈权衡关系。因此，我们认为后胫骨斜率的增加可能导致矫正丢失。
治疗研究，回顾性比较研究，III 级。
