Hernigou P, Besnard P
Hôpital Henri Mondor, Créteil, France.
Rev Chir Orthop Reparatrice Appar Mot. 1994;80(6):503-19.
Only two dimensions of a three dimensional object are visible on plain roentgenograms. Therefore, on gross inspection of antero-posterior and lateral roentgenograms, a screw may project as being safely within the head of the femur even though penetration has occurred. This region may be referred to as a "blind zone".
Unrecognized screw penetration into the hip joint during internal fixation of femoral neck fractures was researched on intra operative roentgenograms of 30 patients. Unrecognized pin penetration through the posterior part of the neck was also analyzed on the same X Rays.
Unrecognized screw penetration into the hip joint was observed in 20 per cent and penetration at the posterior part of the neck was observed in 10 per cent of cases.
Several methods of determining screw position are described and discussed in this study.
在普通X线片上只能看到三维物体的两个维度。因此，在对前后位和侧位X线片进行大体检查时，即使发生了螺钉穿透，螺钉在X线片上可能显示为安全位于股骨头内。这个区域可称为“盲区”。
通过对30例患者术中X线片研究股骨颈骨折内固定期间未被识别的螺钉穿入髋关节的情况。在相同的X线片上也分析了未被识别的钢针穿透颈部后方的情况。
20%的病例观察到未被识别的螺钉穿入髋关节，10%的病例观察到螺钉穿透颈部后方。
本研究描述并讨论了几种确定螺钉位置的方法。
