Nguyen Duong, Ferreira Louis M, Brownhill James R, Faber Kenneth J, Johnson James A
Bioengineering Research Laboratory, The Hand and Upper Limb Centre, St. Joseph's Health Care London, London, Ontario, Canada.
Comput Aided Surg. 2007 May;12(3):152-9. doi: 10.3109/10929080701374315.
Replacement of the diseased shoulder joint with implants is a procedure whose frequency is rapidly increasing. However, glenoid replacement remains challenging due to the difficult joint exposure and visualization of anatomical reference landmarks during the procedure. Improper positioning of the glenoid component can lead to early failure. The objective of this study was to develop and evaluate a Computer Assisted Glenoid Implantation (CAGI) technique to achieve a more accurate and reliable placement of the glenoid component.
Twenty cadaveric scapulae were imaged with CT. The accuracy of an electromagnetic tracking system and 3D surface modeling for the measurement of glenoid position was compared to that of the standard CT-based method. Custom jigs were then developed to track instruments and to correct for scapular motion during in vitro trials. A standardized protocol for determining, in real time, the glenoid position and placement was developed and validated.
The version angles measured by the tracking system, CT, and the 3D modeling software were 0.0 +/- 1.2 degrees , -1.3 +/- 1.0 degrees , and -1.1 +/- 1.1 degrees , respectively. The magnitudes for inclination angles were 0.7 +/- 0.7 degrees , 0.9 +/- 0.8 degrees , and 1.0 +/- 0.7 degrees , respectively. A statistically significant difference was found only between measurements made with the tracking system and with CT (p < 0.05). Testing of the CAGI system in a cadaveric trial resulted in an accuracy of 1.17 degrees of version and 0.60 degrees of inclination. The procedure was readily performed with excellent feedback and guidance for the surgeon.
Preoperative planning using CT imaging with 3D modeling and intraoperative tracking were combined to produce improved accuracy and reliability of glenoid implantation in the setting of total shoulder arthroplasty.
用植入物替换病变的肩关节是一种频率迅速增加的手术。然而，由于手术过程中关节暴露困难以及解剖参考标志难以可视化，肩胛盂置换仍然具有挑战性。肩胛盂部件放置不当会导致早期失败。本研究的目的是开发并评估一种计算机辅助肩胛盂植入（CAGI）技术，以实现肩胛盂部件更准确、可靠的放置。
对20具尸体肩胛骨进行CT成像。将电磁跟踪系统和3D表面建模测量肩胛盂位置的准确性与基于标准CT的方法进行比较。然后开发定制夹具以跟踪器械并在体外试验中校正肩胛骨运动。制定并验证了用于实时确定肩胛盂位置和放置的标准化方案。
跟踪系统、CT和3D建模软件测量的版本角度分别为0.0±1.2度、-1.3±1.0度和-1.1±1.1度。倾斜角度的大小分别为0.7±0.7度、0.9±0.8度和1.0±0.7度。仅在跟踪系统和CT测量之间发现有统计学意义的差异（p<0.05）。在尸体试验中对CAGI系统进行测试，结果显示版本精度为1.17度，倾斜精度为0.60度。该手术操作简便，为外科医生提供了出色的反馈和指导。
将术前使用CT成像和3D建模进行的规划与术中跟踪相结合，提高了全肩关节置换术中肩胛盂植入的准确性和可靠性。
