应用骨盆正位X线片测量全髋关节置换术后髋臼假体方位角的初步研究

Experimental analysis of measurement of anteversion angle of acetabular cup after total hip arthroplasty on the AP pelvic radiograph

目的通过对骨盆正位X线片的测量,归纳前倾角的变化与外展角的关系,同时检验Pettersson公式和Riten Pradhan公式用于骨盆正位X线片测量的可行性和可靠性。方法模拟全髋关节置换术(total hip arthroplasty, THA)手术,将髋臼假体按照不同的外展角、前倾角放置于骨盆标本髋臼中,分别拍摄骨盆正位X线片。对图像进行测量,发现不同角度下髋臼假体投影的变化规律,应用Pettersson公式和Riten Pradhan公式计算假体前倾角,将结果与实际值进行比较。结果两组公式的计算值之间差异无统计学意义(P>0.05),计算值与实际值之间差异有统计学意义(P<0.05)。结论Pettersson公式和Riten Pradhan公式不适用于测量骨盆正位X线片,误差较大。Riten Pradhan公式的实用性较强,计算得到的外展角和前倾角的对应比值表可用于THA后髋臼假体方位角的判断,但仍需进一步试验完善比值表。

Objective We measure the anteversion angle of acetabular cup on the anteroposterior view radiographs of pelvic. To find the relationship between anteversion and abduction angle, and compare the reliability, feasibility and practicability of Pettersson and Riten Pradhan formula. Methods The plain anteroposterior radiographs were taken at va- rious anterior tilt angle of the acetabular cup on the pelvic specimen were projected. We measure, and get the anteversion angle degree by Pettersson and Riten Pradhan formula . The results between experiment and reality were analysed statistically. Results There was no difference between experiment groups （ P 〉 0. 05 ）, and There was difference between experiment and reality group （P 〈 0. 05）. Conclusion The Pettersson and Riten Pradhan formula are not suitable for the anteroposterior view radiographs of pelvic, Riten Pradhan formula is much more practical. The ratio table to confirm the anteversion and abduction angle for clinical practice should to be perfected by further experiment.