LaTIM, Inserm, UMR 1101, SFR IBSAM, UFR médecine, 22, avenue Camille-Desmoulins, CS 93837, 29238 Brest cedex 3, France; CHU de Brest, 2, avenue Foch, 29609 Brest cedex, France.
LaTIM, Inserm, UMR 1101, SFR IBSAM, UFR médecine, 22, avenue Camille-Desmoulins, CS 93837, 29238 Brest cedex 3, France; Université de Bretagne Occidentale, UBL, 3, rue des Archives, CS 93837, 29238 Brest, France.
Orthop Traumatol Surg Res. 2019 Feb;105(1):55-61. doi: 10.1016/j.otsr.2018.11.011. Epub 2018 Dec 17.
In computer-assisted orthopedic surgery, the hip center (HC) can be determined by calculating the center of rotation of the femur in relation to the pelvis. Several methods are available: Gamage, Halvorsen, Pivot or Least-Moving Point (LMP). To our knowledge, no studies have compared these four methods. We therefore conducted in silico and in vitro experiments to assess whether their accuracy and precision in locating the HC and calculating the hip-knee-ankle (HKA) angle were equivalent.
The four methods show similar accuracy and precision.
The in silico experiment assessed the independent influence of four parameters (camera noise, acetabular noise, movement amplitude, and number of circumductions) on accuracy. The accuracy and precision of the four methods and the impact on HKA ankle calculation were assessed in an in vitro study on six cadaver limbs.
In the in silico experiment, all differences according to method were significant (p<0.0002). The Pivot method was the most accurate for acetabular and camera noise, number of circumductions, and movement amplitude. With the LMP, Pivot, Gamage and Halvorsen methods, error was respectively 23.07±8.40 (range 2.10-54.67) mm, 1.98±081 (0.15-4.89) mm, 28.18±3.42 (18.57-37.60) mm and 2.84±1.46 (0.11-9.44) mm depending on camera noise, 1.65±0.72 (0.13-4.80) mm, 0.52±0.22 (0.05-1.23) mm, 3.02±0.57 (0.60-4.78) mm and 0.61±0.27 (0.04-1.82) mm depending on movement amplitude, 0.50±0.20 (0.05-1.34) mm, 0.18±0.08 (0.01-0.44) mm, 0.36±0.14 (0.03-0.80) mm and 0.21±0.09 (0.01-0.55) mm depending on number of circumductions, and 11.30±5.77 (0.56-37.87) mm, 2.78±1.47 (0.10-8.77) mm, 88.08±8.85 (60.59-117.79) mm and 24.33±9.82 (1.40-66.17) mm depending on acetabular noise. In the in vitro experiment, differences were non-significant between the Pivot and LMP methods (p>0.98) and between the Gamage and Halvorsen methods (p>0.65). With the LMP, Pivot, Gamage and Halvorsen methods, precision was respectively 8.2±4.6 (3.3-23.6) mm, 7.3±3.6 (3.4-14.1) mm, 33.6±19.1 (4.7-111.4) mm and 35.0±25.0 (4.7-132.5) mm. Accuracy was 13.5±8.2 (3.2-40.7) mm. 12.3±6.4 (3.2-23.6) mm, 47.0±33.3 (6.2-176.6) mm and 40.3±27.8 (6.1-130.3) mm. The LMP and Pivot methods were thus more accurate and more precise than the Gamage and Halvorsen methods. HKA angle error was 1.1±0.9° (0.1-3.7) and 0.9±0.8° (0.0-2.5) with the LMP and Pivot methods, and 3.2±2.7° (0.0-12.7) and 3.8±3.5° (0.0-13.3) with the Gamage and Halvorsen methods.
The study highlighted differences between the four methods of HC location in computer-assisted surgery; the Pivot method was the most accurate and precise, thus falsifying the study hypothesis.
III, prospective comparative in silico and in vitro study.
在计算机辅助骨科手术中，可以通过计算股骨相对于骨盆的旋转中心来确定髋关节中心（HC）。有几种方法可用：Gamage、Halvorsen、Pivot 或 Least-Moving Point（LMP）。据我们所知，尚无研究比较这四种方法。因此，我们进行了计算机模拟和体外实验，以评估它们在定位 HC 和计算髋膝踝（HKA）角度方面的准确性和精度是否相当。
这四种方法具有相似的准确性和精度。
计算机模拟实验评估了四个参数（相机噪声、髋臼噪声、运动幅度和环转次数）对准确性的独立影响。在六具尸体肢体的体外研究中，评估了这四种方法的准确性和精度以及对 HKA 踝关节计算的影响。
在计算机模拟实验中，根据方法的所有差异均具有统计学意义（p<0.0002）。在考虑到相机噪声、运动幅度和环转次数以及髋臼噪声的情况下，Pivot 方法对于髋臼和相机噪声、环转次数和运动幅度最为准确。使用 LMP、Pivot、Gamage 和 Halvorsen 方法，误差分别为 23.07±8.40（范围 2.10-54.67）mm、1.98±081（0.15-4.89）mm、28.18±3.42（18.57-37.60）mm 和 2.84±1.46（0.11-9.44）mm 取决于相机噪声，1.65±0.72（0.13-4.80）mm、0.52±0.22（0.05-1.23）mm、3.02±0.57（0.60-4.78）mm 和 0.61±0.27（0.04-1.82）mm 取决于运动幅度，0.50±0.20（0.05-1.34）mm、0.18±0.08（0.01-0.44）mm、0.36±0.14（0.03-0.80）mm 和 0.21±0.09（0.01-0.55）mm 取决于环转次数，11.30±5.77（0.56-37.87）mm、2.78±1.47（0.10-8.77）mm、88.08±8.85（60.59-117.79）mm 和 24.33±9.82（1.40-66.17）mm 取决于髋臼噪声。在体外实验中，Pivot 和 LMP 方法之间（p>0.98）以及 Gamage 和 Halvorsen 方法之间（p>0.65）的差异无统计学意义。在 LMP、Pivot、Gamage 和 Halvorsen 方法中，精度分别为 8.2±4.6（3.3-23.6）mm、7.3±3.6（3.4-14.1）mm、33.6±19.1（4.7-111.4）mm 和 35.0±25.0（4.7-132.5）mm。准确性为 13.5±8.2（3.2-40.7）mm。12.3±6.4（3.2-23.6）mm、47.0±33.3（6.2-176.6）mm 和 40.3±27.8（6.1-130.3）mm。因此，LMP 和 Pivot 方法比 Gamage 和 Halvorsen 方法更准确和更精确。HKA 角度误差为 1.1±0.9°（0.1-3.7）和 0.9±0.8°（0.0-2.5）使用 LMP 和 Pivot 方法，而使用 Gamage 和 Halvorsen 方法则为 3.2±2.7°（0.0-12.7）和 3.8±3.5°（0.0-13.3）。
该研究强调了计算机辅助手术中 HC 定位的四种方法之间的差异；Pivot 方法最准确和精确，因此否定了研究假设。
III，前瞻性比较计算机模拟和体外研究。
