不同透视角度下髋臼杯覆盖率:评估复杂类型髋关节发育不良全髋关节置换假体的位置

Coverage of the acetabular cup under different perspective angles:assessing the position of the total hip arthroplasty prosthesis for complex types of hip dysplasia

背景:髋臼杯覆盖率用于评估全髋关节置换术臼杯安放后的包容性与稳定性,而髋关节平片检查是一种普遍的全髋关节置换术中或术后髋臼杯覆盖率评估的一项手段,不同透视角度可能影响髋臼杯覆盖率的测量与评估。目的:探讨全髋关节置换术中不同透视角度下髋臼杯覆盖率之间的关系。方法:取3D打印合成的骨盆标本5个,通过打磨右侧髋臼安放直径52 mm的髋臼杯假体,以制备5个相同全髋关节置换术后髋臼模型。将制备好的骨盆模型以右侧髋臼为中心固定于C型臂机下进行透视,通过旋转C型臂机,透视出右髋关节正位片,上15°,30°,45°轴位片和左15°,30°,45°斜位片。通过Photoshop 2019软件计算出不同透视角度下臼杯覆盖率,比较不同角度轴位片及斜位片下的髋臼杯覆盖率与正位片的差异。结果与结论:(1)在轴位片髋臼杯覆盖率的测试中,随着轴位透视角度向上倾斜,臼杯覆盖率逐渐增大,其中上45°轴位片组显著高于髋关节正位片组[增加(6.72±1.57)%,P=0.009];(2)在斜位片髋臼杯覆盖率测试中,随着透视角度向左倾斜,覆盖率呈下降趋势,其中左45°斜位片组显著低于髋关节正位片组[减少(5.56±1.91)%,P=0.021];(3)结果说明,不同倾斜透视角度下的髋臼杯覆盖率存在差异。向上轴位倾斜角度越大,显示臼杯覆盖越多,而向对侧斜位倾斜角度越大,显示臼杯覆盖越少;提示对于全髋关节置换的患者需注意术中透视角度,而复杂类型的全髋关节置换的患者术中或术后可透视45°斜位片以进一步评估臼杯位置及覆盖。

BACKGROUND:The coverage of acetabular cup is used to evaluate the inclusiveness and stability of the acetabular cup after total hip arthroplasty.Plain radiograph examination of the hip is a common method to detect acetabular cup coverage during or after total hip arthroplasty.Different perspective angles may affect the measurement and evaluation of acetabular cup coverage.OBJECTIVE:To explore the relationship between the coverage of the acetabular cup under different perspectives after total hip arthroplasty.METHODS:Five three-dimensional printed synthetic pelvic specimens were taken,and 52 mm diameter acetabular cup prosthesis was placed by polishing the right acetabulum to prepare different acetabular cup coverage models.The prepared pelvis model was fixed with the right acetabulum as the center under the C-arm machine for fluoroscopy.By rotating the C-arm machine,the right hip joint was seen through the front view,15°,30°,and 45°axial position films and left 15°,30°,and 45°oblique films.The coverage of the acetabular cup under different perspective angles was calculated by Photoshop2019 software to compare the difference between the acetabular cup coverage under the different angles of the axial and oblique films and the orthographic film.RESULTS AND CONCLUSION:(1)In the test of the acetabular cup coverage of the axial film,as the axial perspective angle was tilted upward;the coverage of the acetabular cup gradually increased,and was significantly higher in the upper 45°axial film group than that in the hip orthographic film group[increased(6.72±1.57)%,P=0.009].(2)In the oblique film acetabular cup coverage test,as the perspective angle tilted to the left,the coverage rate showed a downward trend.The coverage was significantly lower in the left 45°oblique film group than that in the hip joint orthographic film group[decreased(5.56±1.91)%,P=0.021].(3)Results confirm that there are differences in the coverage of the acetabular cup under different oblique perspective angles.The greater the upward axial tilt angle,the greater the cup coverage,and the greater the contralateral tilt angle,the less cup coverage.It is indicated that for patients undergoing total hip arthroplasty,attention should be paid to the intraoperative fluoroscopy angle.For complicated types of total hip arthroplasty patients,45°oblique films can be shown during or after the operation to further evaluate the position and coverage of the cup.