Ollivier M, Tribot-Laspiere Q, Amzallag J, Boisrenoult P, Pujol N, Beaufils P
Department of Orthopaedics and Traumatology, Versailles Hospital Center, 78150, Le Chesnay, France.
Clinique Drouot, 20 rue Laffitte, 75009, Paris, France.
Knee Surg Sports Traumatol Arthrosc. 2016 Nov;24(11):3441-3447. doi: 10.1007/s00167-015-3645-1. Epub 2015 May 21.
The aim of this study was to analyze first intraoperative alignment and reason to abandon the use of patient-specific instrumentation using intraoperative CAS measurement, secondly assess by postoperative CT analysis if CI, based on preoperative 3D-MRI data, improved postoperative component positioning (including femoral rotation) and lower limb alignment as compared with results obtained with CAS.
In this randomized controlled trial, 80 consecutive patients scheduled to undergo TKA were enrolled. Eligible knees were randomized to the group of PSI-TKAs (n = 40) or to the group of CAS-TKAs (n = 40). In the CAS group, CAS determined and controlled cutting block positioning in each plane. In the PSI group, CAS allowed to measure adequacy of intraoperative alignment including femoral component rotation. At 3 months after surgery, implants position were measured and analyzed with full-weight bearing plain radiographs and CT scan.
Intraoperatively, there was a significant difference concerning Sagittal Femoral mechanical, Frontal tibial mechanical angle and tibial slope between the two groups (respectively p = 0.01, p = 0.02, p = 0.046). Custom instrumentation was abandoned intraoperatively in seven knees (17.5 %). Abnormal tibial cuts were responsible of the abandon in three out of seven cases, femoral cut in 1/7 and dual abnormalities in 3/7. Postoperatively, tibial slope outliers percentage was higher in the patient specific instrumentation group with six patients (18.18 %) versus one patient (2.5 %) in the CAS group (p = 0.041).
Patient specific instrumentation was associated with an important number of hazardous cut and a higher rate of outliers in our series and thus should be used with caution as related to. This study is the first to our acknowledgement to compare intra-operative ancillary and implant positioning of PSI-TKA and CAS-TKA. High rate of malposition are sustained by our findings, as such PSI-TKA should be used with caution, by surgeons capable to switch to conventional instrumentation intra-operatively.
Randomized control trial, Level I.
本研究的目的，一是使用术中计算机辅助手术（CAS）测量分析首次术中对线情况以及放弃使用患者特异性器械的原因；二是通过术后CT分析评估基于术前三维磁共振成像（3D-MRI）数据的计算机导航（CI）与CAS相比是否能改善术后假体位置（包括股骨旋转）和下肢对线。
在这项随机对照试验中，连续纳入80例计划接受全膝关节置换术（TKA）的患者。符合条件的膝关节被随机分为患者特异性器械全膝关节置换术组（n = 40）或计算机辅助手术全膝关节置换术组（n = 40）。在CAS组中，CAS确定并控制每个平面的截骨模块位置。在PSI组中，CAS用于测量术中对线的充分性，包括股骨假体旋转。术后3个月，通过全负重X线平片和CT扫描测量并分析植入物位置。
术中，两组之间在股骨矢状面机械角、胫骨额状面机械角和胫骨坡度方面存在显著差异（分别为p = 0.01、p = 0.02、p = 0.046）。术中七例膝关节（17.5%）放弃使用定制器械。七例中有三例因胫骨截骨异常而放弃，一例因股骨截骨异常，三例因双重异常。术后，患者特异性器械组胫骨坡度异常值百分比更高，有六例患者（18.18%），而CAS组为一例患者（2.5%）（p = 0.041）。
在我们的研究系列中，患者特异性器械与大量危险截骨和更高的异常值发生率相关，因此使用时应谨慎。本研究是我们所知的第一项比较患者特异性器械全膝关节置换术（PSI-TKA）和计算机辅助手术全膝关节置换术（CAS-TKA）术中辅助操作和植入物位置的研究。我们的研究结果表明错位率较高，因此PSI-TKA应由有能力在术中切换到传统器械的外科医生谨慎使用。
随机对照试验，I级。
