PURPOSE There are two established techniques for high tibial valgisation osteotomy (HTO): medial open wedge (MOW) and lateral closed wedge (LCW). The aim was to analyze the change of the posterior tibial slope (PTS) caused by HTOs dependent on the technique. METHODS Four hundred fourteen cases of HTOs were analyzed retrospectively. Two hundred seventy-nine osteotomies in 247 patients matched the inclusion criteria and were divided into two treatment groups (MOW/LCW). The PTS was determined on pre- and post-surgical lateral knee X-rays by measuring the proximal posterior tibial angle (PPTA). RESULTS One hundred ninety of the included 279 cases were assigned to the MOW and 89 to the LCW group. The mean PPTA in MOW HTOs was 79.9° ± 32° (68-88°) and in LCW HTOs 80.6° ± 2.6° (74-88°). There was no statistically significant change of the PPTA in the MOW group comparing the pre- and post-surgical values (delta PPTA 0.07° ±2.9° (- 12 to 11°)). In the LCW group, the surgery resulted in a statistically significant reduction (p< 0.001) of the PTS (delta PPTA - 3.09° ± 4.5° (- 12 to 5°)). CONCLUSION The important finding of this study is that the thesis of a slope increase in MOW osteotomies found in the literature could not be approved regarding our results as no statistically significant change of PTS in MOW HTOs was observed. The findings support the common thesis that LCW osteotomies cause a slope reduction.

中文翻译：

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开放式和封闭式高位胫骨截骨术对胫骨后倾斜的影响-279例研究。

目的有两种成熟的用于高位胫腓翻截骨术（HTO）的技术：内侧开口楔形术（MOW）和外侧闭合楔形术（LCW）。目的是分析依赖于该技术的HTO引起的胫骨后倾斜度（PTS）的变化。方法对144例HTO进行回顾性分析。247例患者中的279例截骨符合入选标准，并分为两个治疗组（MOW / LCW）。通过测量胫骨近端后角（PPTA），在术前和术后外侧膝关节X线检查中确定PTS。结果在279例病例中，有190例分配给了MOW，而89例分配给了LCW组。MOW HTO的平均PPTA为79.9°±32°（68-88°），LCW HTO的平均PPTA为80.6°±2.6°（74-88°）。与手术前和手术后的值相比，MOW组的PPTA没有统计学上的显着变化（PPTAδ为0.07°±2.9°（-12至11°））。在LCW组中，手术导致PTS统计学上显着降低（p <0.001）（δPPTA-3.09°±4.5°（-12至5°））。结论这项研究的重要发现是，就我们的结果而言，文献中发现的MOW截骨术的斜率增加的论点不能被批准，因为未观察到MOW HTO中PTS的统计学显着变化。这些发现支持了LCW截骨术可减少斜率这一普遍论点。5°（-12至5°））。结论这项研究的重要发现是，就我们的结果而言，文献中发现的MOW截骨术的斜率增加的论点不能被批准，因为未观察到MOW HTO中PTS的统计学显着变化。这些发现支持了LCW截骨术导致斜率降低的一般论点。5°（-12至5°））。结论这项研究的重要发现是，就我们的结果而言，文献中发现的MOW截骨术的斜率增加的论点不能被批准，因为未观察到MOW HTO中PTS的统计学显着变化。这些发现支持了LCW截骨术可减少斜率这一普遍论点。