Kafchitsas Konstantinos, Rauschmann Michael
Department of Orthopaedic Surgery, Johann Wolfgang Goethe University Frankfurt am Main, Frankfurt am Main, Germany.
Comput Aided Surg. 2009;14(1-3):28-36. doi: 10.3109/10929080903016177.
Previous studies have shown that total disc replacement (TDR) resulted in significantly better restoration of disc-space height and significantly less subsidence than anterior interbody fusion with BAK cages. Clinical outcomes and flexion/extension range of motion correlated with the accuracy of surgical placement of the CHARITÉ™ artificial disc. False positioning of the artificial disc leads to spondylarthrosis and disc degeneration of the adjacent segment, and exclusive use of a C-arm could cause such false positioning (due to the parallax effect). The objective of this study was to test and evaluate the accuracy of navigated artificial disc replacement as performed by a spine surgeon without a prior learning curve. In each case, the placement position achieved by the surgeon was compared with the preoperatively planned position for that specimen.
Lumbar intervertebral disc prostheses (CHARITÉ™ , DePuy Spine) were placed using an image guidance technique (BrainLAB VectorVision system) in ten human cadaveric spine specimens. A total of 15 such disc replacements were performed using navigation. Post-instrumentation accuracy was assessed by a computer on the basis of CT scans.
The placement of the disc was assessed as ideal (<3 mm from the planned position), suboptimal (3-5 mm from the planned position) or poor (>5 mm from the planned position). Only three disc prostheses were placed suboptimally, and none was poorly placed. Placement in the coronal plane was significantly better than in the other planes.
Navigation is a useful instrument in the hands of the spine surgeon, enabling an ideal placement of the disc prosthesis. Navigation offers greater accuracy and less inter-procedural variation than standard fluoroscopy (due to the parallax effect). As accurate (ideal or suboptimal) placement correlates with good clinical outcome, further clinical studies on the navigation of TDR are essential. In this present study, the disc replacement was performed by a surgeon without experience in total disc replacement, indicating that prior completion of a learning curve was not essential.
先前的研究表明，与使用BAK椎间融合器进行前路椎间融合术相比，全椎间盘置换术（TDR）能显著更好地恢复椎间隙高度，且下沉明显更少。临床结果以及屈伸活动范围与CHARITÉ™人工椎间盘手术置入的准确性相关。人工椎间盘的错误定位会导致相邻节段的脊椎关节病和椎间盘退变，而仅使用C形臂可能会导致这种错误定位（由于视差效应）。本研究的目的是测试和评估脊柱外科医生在无预先学习曲线的情况下进行的导航人工椎间盘置换术的准确性。在每种情况下，将外科医生实现的置入位置与该标本术前计划的位置进行比较。
使用图像引导技术（BrainLAB VectorVision系统）在10个人类尸体脊柱标本中置入腰椎间盘假体（CHARITÉ™，DePuy Spine）。使用导航共进行了15次此类椎间盘置换。术后仪器置入准确性由计算机根据CT扫描进行评估。
椎间盘的置入被评估为理想（距计划位置<3毫米）、次优（距计划位置3 - 5毫米）或差（距计划位置>5毫米）。只有3个椎间盘假体置入次优，没有一个置入不佳。在冠状面的置入明显优于其他平面。
导航在脊柱外科医生手中是一种有用的工具，可实现椎间盘假体的理想置入。与标准荧光透视法相比，导航具有更高的准确性和更小的术中变化（由于视差效应）。由于准确（理想或次优）置入与良好的临床结果相关，因此对TDR导航进行进一步的临床研究至关重要。在本研究中，椎间盘置换由一位没有全椎间盘置换经验的外科医生进行，这表明预先完成学习曲线并非必要。
