Schwarzkopf Ran, Vigdorchik Jonathan M, Miller Theodore T, Bogner Eric A, Muir Jeffrey M, Cross Michael B
Orthopedics. 2017 Nov 1;40(6):e952-e958. doi: 10.3928/01477447-20170918-03. Epub 2017 Sep 22.
Postoperative radiographs remain the standard for assessment of component placement following total hip arthroplasty (THA), despite the known limitations of radiographs. Computed tomography (CT) scanning offers improved accuracy, but its costs and radiation exposure are prohibitive. The authors performed a cadaver study to compare the error associated with radiographs with that of CT scans following THA. The authors also compared imaging with a novel mini-navigation system. Three board-certified orthopedic surgeons each performed 4 THA procedures (6 cadavers, 12 hips) via the posterior approach using a mini-navigation tool to assist with component placement. Cup position from imaging was compared with corrected CT values for anteversion and inclination, created by correcting the initial scan to align the anterior pelvic plane coplanar with the CT table, thus representing cup position not distorted by imaging or positioning. Anteversion from standard CT scans was within 2.5° (standard deviation [SD], 1.5°) of reference values (P=.25); radiographs showed an average error of 7.8° (SD, 4.3°) vs reference values (all values absolute means) (P<.01). The mini-navigation system provided anteversion values within an average of 4.0° (SD, 4.0°) of reference anteversion (P<.01). Standard CT values for inclination were within 2.4° (SD, 2.0°) of reference values (P=.53), whereas radiographic inclination values were within 2.5° (SD, 2.3°) (P=.12). Mini-navigation values for inclination were within 3.9° (SD, 3.2°) of reference inclination (P=.26). This study demonstrated that cup position as measured by radiographs is significantly less accurate than CT scans and that the mini-navigation system provided anteversion measurements that were of comparable accuracy to CT scans. [Orthopedics. 2017; 40(6):e952-e958.].
尽管已知X线片存在局限性，但术后X线片仍是全髋关节置换术（THA）后评估假体组件位置的标准方法。计算机断层扫描（CT）扫描提供了更高的准确性，但其成本和辐射暴露令人望而却步。作者进行了一项尸体研究，以比较THA后X线片与CT扫描相关的误差。作者还将成像与一种新型微型导航系统进行了比较。三名获得董事会认证的骨科医生每人通过后路使用微型导航工具辅助组件放置，进行了4例THA手术（6具尸体，12髋）。将成像得到的髋臼位置与通过校正初始扫描使骨盆前平面与CT检查台共面而创建的髋臼前倾角和倾斜角的校正CT值进行比较，从而代表未因成像或定位而扭曲的髋臼位置。标准CT扫描的前倾角在参考值的2.5°（标准差[SD]，1.5°）范围内（P = 0.25）；X线片显示与参考值相比平均误差为7.8°（SD，4.3°）（所有值均为绝对均值）（P < 0.01）。微型导航系统提供的前倾角值平均在参考前倾角的4.0°（SD，4.0°）范围内（P < 0.01）。倾斜角的标准CT值在参考值的2.4°（SD，2.0°）范围内（P = 0.53），而X线片的倾斜角值在2.5°（SD，2.3°）范围内（P = 0.12）。微型导航的倾斜角值在参考倾斜角的3.9°（SD，3.2°）范围内（P = 0.26）。这项研究表明，X线片测量的髋臼位置准确性明显低于CT扫描，并且微型导航系统提供的前倾角测量准确性与CT扫描相当。[《骨科》。2017；40（6）：e952 - e958。]
