Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan.
Department of Orthopaedic Surgery, Fujita Health University, Toyoake, Aichi, Japan.
J Bone Joint Surg Am. 2020 Nov 18;102(22):1993-2000. doi: 10.2106/JBJS.20.00387.
An accelerometer-based portable navigation system was recently introduced to improve prosthetic alignment during total knee arthroplasty (TKA). The purpose of this multicenter prospective randomized controlled trial (RCT) was to evaluate the effects of this accelerometer-based portable navigation system for achieving more accurate alignment during TKA in the clinical setting.
One hundred patients with primary varus osteoarthritis of the knee were enrolled in this prospective RCT conducted in 5 hospitals. A navigation system was utilized in 50 patients (navigation group), and a conventional intramedullary femoral guide and an extramedullary tibial guide were utilized in 50 patients (conventional group). At 6 months postoperatively, weight-bearing radiographs were obtained of the whole operative leg. An experienced surgeon who was blinded to the treatment assignments then measured the alignment to 1 decimal place with use of computer software. Power analysis showed that 41 knees were required in each group.
There were no complications as a result of the use of the accelerometer-based portable navigation system. Postoperative radiographs were obtained in 45 patients from each group. There were no significant differences in sex, age, height, body weight, body mass index, preoperative femorotibial angle, and operative time between groups. The absolute differences of the femoral prosthesis (p = 0.01), tibial prosthesis (p < 0.01), and hip-knee-ankle angle (p < 0.01) from a neutral mechanical axis were less in the navigation group compared with those in the conventional group. Alignment outliers (>2° away from the neutral mechanical axis) of the tibial prosthesis and hip-knee-ankle angle were less in the navigation group (9% and 27%, respectively) compared with those in the conventional group (31% and 49%; p = 0.01 and p = 0.04, respectively).
To our knowledge, this is the first multicenter prospective RCT to evaluate an accelerometer-based portable navigation system. An accelerometer-based portable navigation system provides more accurate prosthetic and limb alignment in the coronal plane than conventional techniques, without extended operative time or an increased rate of complications. The results of this study may help orthopaedic surgeons decide whether or not to use an accelerometer-based portable navigation system.
Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
最近引入了一种基于加速度计的便携式导航系统，以改善全膝关节置换术（TKA）中的假肢对准。这项多中心前瞻性随机对照试验（RCT）的目的是评估这种基于加速度计的便携式导航系统在临床环境中实现更精确 TKA 对准的效果。
这项前瞻性 RCT 在 5 家医院进行，共纳入 100 例原发性膝关节内侧骨关节炎患者。50 例患者使用导航系统（导航组），50 例患者使用传统髓内股骨导向器和髓外胫骨导向器（常规组）。术后 6 个月，对整个手术腿进行负重位 X 线检查。一位经验丰富的外科医生在不知道治疗分组的情况下，使用计算机软件测量对齐情况到小数点后一位。功效分析显示每组需要 41 个膝关节。
使用基于加速度计的便携式导航系统没有发生并发症。每组均有 45 例患者获得术后 X 线片。两组间性别、年龄、身高、体重、体重指数、术前股胫角和手术时间均无显著差异。导航组股骨假体（p=0.01）、胫骨假体（p<0.01）和髋膝踝角（p<0.01）与中立机械轴的绝对差值小于常规组。导航组胫骨假体和髋膝踝角的对线异常（偏离中立机械轴 2°以上）发生率（分别为 9%和 27%）低于常规组（分别为 31%和 49%；p=0.01 和 p=0.04）。
据我们所知，这是第一项评估基于加速度计的便携式导航系统的多中心前瞻性 RCT。与传统技术相比，基于加速度计的便携式导航系统在冠状面提供更精确的假体和肢体对准，而不会延长手术时间或增加并发症发生率。本研究结果可能有助于骨科医生决定是否使用基于加速度计的便携式导航系统。
治疗水平 I. 有关证据水平的完整说明，请参阅作者说明。
