Hankemeier S, Hufner T, Wang G, Kendoff D, Zeichen J, Zheng G, Krettek C
Trauma Department of Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Knee Surg Sports Traumatol Arthrosc. 2006 Oct;14(10):917-21. doi: 10.1007/s00167-006-0035-8. Epub 2006 Feb 24.
High tibial osteotomy (HTO) is an established therapy for the treatment of symptomatic varus malaligned knees. A main reason for disappointing clinical results after HTO is the under- and overcorrection of the mechanical axis due to insufficient intraoperative visualisation. Twenty legs of fresh human cadaver were randomly assigned to navigated open-wedge HTO (n=10) or conventional HTO using the cable method (n=10). Regardless of the pre-existing alignment, the aim of all operations was to align the mechanical axis to pass through 80% of the tibial plateau (beginning with 0% at the medial edge of the tibial plateau and ending with 100% at the lateral edge). This overcorrection was chosen to ensure a sufficient amount of correction. Thus, the medial proximal tibia angle (MPTA) increased by 9.1+/-2.9 degrees (range 5.2 degrees -12.3 degrees ) on the average after navigated HTO and by 8.9+/-2.9 degrees (range 4.7 degrees -12.6 degrees ) after conventional HTO. After stabilization with a fixed angle implant, the alignment was measured by CT. After navigated HTO, the mechanical axis passed the tibial plateau through 79.7% (range 75.5-85.8%). In contrast, after conventional HTO, the average intersection of the mechanical axis was at 72.1% (range 60.4-82.4%) (P=0.020). Additionally, the variability of the mean corrections was significantly lower in the navigated group (3.3% vs. 7.2%, P=0.012). Total fluoroscopic radiation time was significantly lower in the navigated group (P=0.038) whereas the mean dose area product was not significantly different (P=0.231). The time of the operative procedure was 23 min shorter after conventional HTO (P<0.001). Navigation systems provide intraoperative 3-dimensional real time control of the frontal, sagittal, and transverse axis and may increase the accuracy of open-wedge HTO. Future studies have to analyse the clinical effects of navigation on corrective osteotomies.
高位胫骨截骨术（HTO）是治疗有症状的膝内翻畸形的既定疗法。HTO术后临床效果不尽人意的一个主要原因是术中可视化不足导致机械轴矫正不足或过度矫正。将20条新鲜人尸体下肢随机分为导航下开放楔形HTO组（n = 10）或使用缆线法的传统HTO组（n = 10）。无论术前对线情况如何，所有手术的目标都是使机械轴穿过胫骨平台的80%（从胫骨平台内侧边缘的0%开始，到外侧边缘的100%结束）。选择这种过度矫正以确保有足够的矫正量。因此，导航下HTO术后平均胫骨近端内侧角（MPTA）增加了9.1±2.9度（范围为5.2度至12.3度），传统HTO术后增加了8.9±2.9度（范围为4.7度至12.6度）。用固定角度植入物稳定后，通过CT测量对线情况。导航下HTO术后，机械轴穿过胫骨平台的比例为79.7%（范围为75.5 - 85.8%）。相比之下，传统HTO术后，机械轴的平均交点位于72.1%（范围为60.4 - 82.4%）（P = 0.020）。此外，导航组平均矫正的变异性显著更低（3.3%对7.2%，P = 0.012）。导航组的总透视辐射时间显著更低（P = 0.038），而平均剂量面积乘积无显著差异（P = 0.231）。传统HTO术后手术时间短23分钟（P < 0.001）。导航系统可提供术中对额状轴、矢状轴和横轴的三维实时控制，并可能提高开放楔形HTO的准确性。未来的研究必须分析导航对矫正截骨术的临床效果。
