Kang Dong-Geun, Kim Kang-Il, Bae Jung-Kwon
Department of Orthopaedic Surgery, Kyung Hee University Hospital at Gangdong, 892 Dongnam-ro, Gangdong-gu, Seoul, 134-727, South Korea.
Arthroplasty. 2020 Jan 14;2(1):1. doi: 10.1186/s42836-019-0020-6.
Patient-specific instrumentation (PSI) has been introduced into total knee arthroplasty (TKA) to improve accuracy in restoration of alignment. PSI in TKA refers to custom-made cutting jigs manufactured according to anatomic configuration of the patient's bone based on preoperative magnetic resonance imaging (MRI) or computed tomography (CT) scans. The purpose of this study was to compare the MRI- or CT-based PSI to see if they could reproduce accurate bone resection and postoperative outcomes.
Seventy-one patients who received elective TKA using a PSI system for primary osteoarthritis with varus deformity were prospectively enrolled for this study. We randomly allocated those patients to MRI-based PSI group (36 patients) and CT-based PSI group (35 patients). The actual resection thickness and planned resection thickness by preoperative PSI electronic program were compared between the two groups. Radiographic findings of the postoperative limb alignment, three-dimensional position of the implants, and related complications were also evaluated. Clinical evaluation was also performed before and 2 years after the surgery.
There were no significant differences in the resection thickness in femur and tibia between actual resection and planned resection in both groups. Furthermore, there were no significant differences between two groups in terms of coronal, sagittal and rotational alignment of the components. All clinical assessments revealed no differences between two groups 2 years after the operation. No specific complication related to PSI was observed.
Although MRI allows for visualization of cartilage, MRI-based PSI system did not show better accuracy in predicting the thickness of bone resection than CT-based PSI. Moreover, there were no differences in radiographic and clinical outcomes between the two groups.
患者特异性器械（PSI）已被引入全膝关节置换术（TKA），以提高对线恢复的准确性。TKA中的PSI是指根据患者术前磁共振成像（MRI）或计算机断层扫描（CT）扫描的骨骼解剖结构定制的切割导板。本研究的目的是比较基于MRI或CT的PSI，看它们是否能再现准确的骨切除及术后结果。
前瞻性纳入71例因原发性骨关节炎伴内翻畸形接受使用PSI系统的择期TKA患者。我们将这些患者随机分为基于MRI的PSI组（36例患者）和基于CT的PSI组（35例患者）。比较两组术前PSI电子程序的实际切除厚度和计划切除厚度。还评估了术后肢体对线的影像学表现、植入物的三维位置及相关并发症。术前及术后2年也进行了临床评估。
两组实际切除与计划切除的股骨和胫骨切除厚度均无显著差异。此外，两组在假体的冠状面、矢状面和旋转对线方面也无显著差异。所有临床评估显示术后2年两组之间无差异。未观察到与PSI相关的特定并发症。
尽管MRI可显示软骨，但基于MRI的PSI系统在预测骨切除厚度方面并未显示出比基于CT的PSI更好的准确性。此外，两组在影像学和临床结果方面无差异。
