髋关节股骨假体远端中心化状态的定量评估

目的采用CT成像技术评估髋关节置换术后股骨假体远端的中心化状态。方法对18个人工全髋关节股骨假体柄的第4区进行CT扫描,并以股骨髓腔中心为原点,以股骨远端内外后髁连线的平行线作为X轴,建立直角坐标系,对假体柄远端进行测量分析。结果通过CT扫描可以更直观、准确地显示假体柄远端在骨髓腔中的位置。测量所得的圆心距(假体柄远端中心点与股骨髓腔中心点的距离)、股骨髓腔半径以及假体柄尖所在的象限和象限值,可以作为股骨假体远端中心化状态的量化指标。结论由于CT扫描的介入,可以对股骨假体远端中心化状态进行量化观察,为指导临床医生研究和改进手术技术,判断术后临床效果,提供了一种准确、量化的评估方法,也为相关研究提供了可靠的基础。

Evaluation of the centralization status of the distal stem of hip femoral prosthesis

Objective To evaluate the centralization of the distal stem of hip femoral prosthesis after total hip replacement with CT imaging. Methods T he 4th zone of the femoral stem of hip prosthesis in 18 cases was scanned with c omputerized tomography; the affected limb was fixed, the window level was 1 500 to 2 000. The rectangular coordinat was established, its origin was the center o f femoral medullary cavity, and the line parallel with the connecting line betwe en the posterior borders of femoral medial lateral condyles was X axis. The foll owed variables were recorded on CT imaging: 1)the distance of the centers(the me dullary cavity center and femoral prosthetic center); 2) medullary cavity radius ; 3) the distance of the centers/medullary cavity radius; 4) the relationship of the prosthetic hip and quadrant; 5) metal pseudo imagines.The distal femoral st em of hip prosthesis could be measured and analyzed. Results Through CT scan, th e location of the distal stem in femoral medullary cavity could be accurately sh own and viewed directly. The distances between the femoral stem tips and the cen ters of medullary cavity, the radius of femoral medullary cavity, and the quadra nt which the stem tips are located at, could be considered as quantitative indic es on the centralization of the femoral distal stem of hip prosthesis. Conclusio n The centralized status of the distal stem of hip prosthesis can be observed wi th CT imaging. CT imaging is a kind of accurate and quantitative analysis method . It not only can guide the doctor to study and improve the surgical techniques, but also offer a reliable basis for correlative research. [