Hankemeier Stefan, Hufner Tobias, Wang Gongli, Kendoff Daniel, Zheng Guoyan, Richter Martinus, Gosling Thomas, Nolte Lutz, Krettek Christian
Trauma Department, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Arch Orthop Trauma Surg. 2005 Oct;125(8):531-5. doi: 10.1007/s00402-005-0038-9. Epub 2005 Oct 22.
Accurate intraoperative assessment of lower limb alignment is crucial for the treatment of long bone fractures, implantation of knee arthroplasties and correction of deformities. During orthopaedic surgery, exact real time control of the mechanical axis is strongly desirable. The aim of this study was to compare conventional intraoperative analysis of the mechanical axis by the cable method with continuous, 3-dimensional imaging with a navigation system.
Twenty legs of fresh human cadaver were randomly assigned to conventional analysis with the cable method (n = 10) or navigated analysis with a fluoroscopy based navigation system (n = 10). The intersection of the mechanical axis with the tibia plateau was presented as percentage of the tibia plateau (beginning with 0% at the medial border and ending with 100% laterally). CT-scans were performed for all legs and the CT-values of the mechanical axis were compared to the measurements after cable method and navigation. Furthermore, the radiation time and dose area product of both groups for single analysis of the mechanical axis was compared.
Conventional evaluation of the mechanical axis by the cable method showed 6.0+/-3.1% difference compared to the analysis by CT. In the navigated group the difference was 2.6+/-1.8% (P = 0.008). Radiation time and dose area product were highly significantly lower after conventional measurement.
Navigated intraoperative evaluation of the mechanical axis offers increased accuracy compared to conventional intraoperative analysis. Furthermore, navigation provides continuous control not only of the mechanical axis, but also of the sagittal and transverse plane. Using the cable method, radiation exposure depends on the number of measurements and is lower compared to the navigation system for single intraoperative analysis of the mechanical axis, but may be higher in case of repeated intraoperative measurements.
准确的术中下肢对线评估对于长骨骨折的治疗、膝关节置换术的植入以及畸形矫正至关重要。在骨科手术中，非常需要对机械轴进行精确的实时控制。本研究的目的是比较通过缆线法进行的传统术中机械轴分析与使用导航系统进行的连续三维成像。
将20条新鲜人体尸体下肢随机分为缆线法传统分析组（n = 10）或基于荧光透视的导航系统导航分析组（n = 10）。机械轴与胫骨平台的交点以胫骨平台的百分比表示（从内侧边缘的0%开始，到外侧的100%结束）。对所有下肢进行CT扫描，并将机械轴的CT值与缆线法和导航测量后的结果进行比较。此外，比较两组单次分析机械轴时的辐射时间和剂量面积乘积。
与CT分析相比，缆线法对机械轴的传统评估显示差异为6.0±3.1%。在导航组中，差异为2.6±1.8%（P = 0.008）。传统测量后的辐射时间和剂量面积乘积显著更低。
与传统术中分析相比，导航术中对机械轴的评估准确性更高。此外，导航不仅能持续控制机械轴，还能控制矢状面和横断面。使用缆线法时，辐射暴露取决于测量次数，在单次术中分析机械轴时比导航系统低，但在术中重复测量时可能更高。
