Yamamura Kazumasa, Minoda Yukihide, Mizokawa Shigekazu, Ohta Yoichi, Sugama Ryo, Nakamura Suguru, Ueyama Hideki, Nakamura Hiroaki
Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi Abeno-ku, Osaka, 545-8585, Japan.
Arch Orthop Trauma Surg. 2017 Mar;137(3):401-407. doi: 10.1007/s00402-017-2628-8. Epub 2017 Jan 17.
This study was designed to evaluate the true accuracy of patient specific instrumentation (PSI) for total knee arthroplasty (TKA) using a new 3D measurement method.
Consecutive 21 patients (30 knees) who underwent TKA using computed tomography (CT)-based PSI were retrospectively evaluated. Mean patient age was 69.2 years (62 to 77). The postoperative three-dimensional (3D) CT image were superimposed onto the preoperative 3D CT plan and measured the absolute difference in the prosthetic alignment using six parameters: coronal, sagittal, and axial alignment of the femoral and tibial prostheses. Cases in which the difference in the prosthetic alignment was greater than 3° were considered outliers.
For the femoral prosthesis, mean absolute differences between the preoperative 3D CT plan and postoperative 3D CT image were not significantly different and the rates of outliers were 10.0, 33.3, 23.3% in the coronal, sagittal, and axial planes. For the tibial prosthesis, mean absolute differences were significantly larger in the axial plane than in the coronal and sagittal planes (p < 0.001) and the rates of outliers were 23.3, 36.7, 63.3% in the coronal, sagittal, and axial planes. The rates of outliers for the axial alignment of tibial prosthesis were significantly higher than for the other five planes (p = 0.006).
The rotation of the tibial prosthesis with CT-based PSI was less accurate in the axial plane than in the other five planes.
本研究旨在使用一种新的三维测量方法评估全膝关节置换术（TKA）中患者特异性器械（PSI）的真实准确性。
回顾性评估连续21例（30膝）接受基于计算机断层扫描（CT）的PSI进行TKA的患者。患者平均年龄为69.2岁（62至77岁）。将术后三维（3D）CT图像叠加到术前3D CT计划上，并使用六个参数测量假体对线的绝对差异：股骨和胫骨假体的冠状面、矢状面和轴面排列。假体对线差异大于3°的病例被视为异常值。
对于股骨假体，术前3D CT计划与术后3D CT图像之间的平均绝对差异无显著差异，冠状面、矢状面和轴面的异常值率分别为10.0%、33.3%、23.3%。对于胫骨假体，轴面的平均绝对差异显著大于冠状面和矢状面（p < 0.001），冠状面、矢状面和轴面的异常值率分别为23.3%、36.7%、63.3%。胫骨假体轴面排列的异常值率显著高于其他五个平面（p = 0.006）。
基于CT的PSI中胫骨假体在轴面的旋转准确性低于其他五个平面。
