Vigdorchik Jonathan M, Cross Michael B, Bogner Eric A, Miller Theodore T, Muir Jeffrey M, Schwarzkopf Ran
Department of Orthopaedic Surgery, NYU Langone Medical Center-Hospital for Joint Diseases, New York, New York.
Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York.
Surg Technol Int. 2017 Jul 25;30:447-454.
Accurate measurement of acetabular cup position (CP), changes in leg length (LL), and offset (OS) are paramount in ensuring proper sizing and implantation of components during total hip arthroplasty (THA). LL/OS inaccuracies can cause low back pain, neurological deficits, and patient dissatisfaction, while inaccurate positioning of the acetabular cup can lead to instability, dislocation, and, ultimately, revision surgery. The objective of this study was to evaluate the accuracy of a mini-navigation tool in measuring CP and LL/OS differential during THA.
Three board-certified orthopedic surgeons each performed four THA procedures via the posterior approach on six cadavers (12 hips) utilizing a novel mini-navigation tool. Imaging included pre- and post-operative radiographs and post-operative CT scans. Image analysis was performed by two radiologists not involved in the surgical procedures. System accuracy regarding measurement of cup position (anteversion and inclination) was determined by comparing the CT measurement of cup orientation with data gathered intraoperatively by probing the face of the implanted cup with the navigation tool and recording the coordinates.
The mean absolute difference between CT and device measurements of cup position was 0.74º (SD: 0.47, range: 0.19-1.48) for anteversion and 0.97º (SD: 0.67, range: 0.27-2.57) for inclination. The mean difference between device and radiograph measurements of LL changes was 0.27 mm (SD: 3.61, range: -5.20-7.78) (absolute mean: 2.71±2.25 mm), while the mean difference in OS was 1.75 mm (SD: 3.00, range: -2.47-6.65) (absolute mean: 2.37±2.44 mm).
This novel mini-navigation tool measured CP, LL, and OS accurately when compared with implant position measured on imaging.
在全髋关节置换术（THA）中，准确测量髋臼杯位置（CP）、下肢长度（LL）变化和偏移（OS）对于确保组件的正确尺寸选择和植入至关重要。LL/OS不准确会导致腰痛、神经功能缺损和患者不满，而髋臼杯定位不准确会导致不稳定、脱位，并最终导致翻修手术。本研究的目的是评估一种微型导航工具在THA期间测量CP和LL/OS差异的准确性。
三位获得骨科专业认证的外科医生各自使用一种新型微型导航工具，通过后入路对六具尸体（12个髋关节）进行了四次THA手术。成像包括术前和术后的X线片以及术后的CT扫描。图像分析由两名未参与手术的放射科医生进行。通过将髋臼杯方向的CT测量值与术中使用导航工具探测植入杯表面并记录坐标所收集的数据进行比较，确定系统在测量杯位置（前倾角和倾斜角）方面的准确性。
杯位置的CT测量值与设备测量值之间的平均绝对差异在前倾角方面为0.74°（标准差：0.47，范围：0.19 - 1.48），在倾斜角方面为0.97°（标准差：0.67，范围：0.27 - 2.57）。设备测量值与X线片测量值在LL变化方面的平均差异为0.27毫米（标准差：3.61，范围： - 5.20 - 7.78）（平均绝对值：2.71±2.25毫米），而OS方面的平均差异为1.75毫米（标准差：3.00，范围： - 2.47 - 6.65）（平均绝对值：2.37±2.44毫米）。
与成像上测量的植入物位置相比，这种新型微型导航工具能够准确测量CP、LL和OS。
