利用三维测量手段验证二维影像引导术中股骨颈骨折复位的局限性的研究

Verification of the limitations about two- dimensional image navigation for femoral neck fracture's reduction by three-dimensional measurement

目的利用三维测量方法测量股骨头残留空间移位程度,验证二维影像资料引导股骨颈骨折闭合复位术是否具有局限性。方法纳入91例股骨颈骨折患者,按骨折类型分为移位和非移位型两组。建立术后近端股骨三维模型,测量股骨头残留移位量,评价复位效果。测量参数:股骨头中心移位量(d)、股骨头小凹-中心连线偏转角度(α)、股骨头自旋角度(β)、股骨颈短缩量(L)。比较两组间各指标的差异性。结果 d和α在移位型、非移位型两组中无统计学差异(P=0.62;P=0.70)。β和L在移位型和非移位型骨折两组中,差异有统计学意义(P=0.047;P=0.019)。结论利用二维影像方法在术中引导股骨颈骨折复位存在明显的复位不良现象,具有明显的局限性。

Objective A three-dimensional measuring method was proposed for evaluation of the reduction quality of displaced or undisplaced femoral neck fractures with closed reduction and internal fixation surgery. Then, summarizing up the displacement tendency of the femoral head provides a theoretical basis for better fracture treatment using an appropriate manual reduction. Methods 91 patients with femoral neck fractures were categorized into two groups： an undisplaced fracture group and a displaced fracture group. Three-dimensional models were constructed. Some parameters were measured： spatial distance displacement of the femoral head center（d）, deflection angle of the femoral head（α）;Self-rotation angle of the femoral head（β）, shortened values of the femoral neck（L）. Results There was no significant difference between the undisplaced and displaced groups concerning the displacement distance of femoral head’s center, flection angle （P=0.62;P=0.70）. There was significant difference between the undisplaced and displaced groups concerning the self-rotation angle of the femoral head, shortened values of the femoral neck （P=0.047; P=0.019）. Conclusion It is not adequate to evaluate the reduction quality of femoral neck fractures merely using the two-dimensional method. X-ray radiographs have some limitations in accurate descriptions when it comes to spatial displacement, especially rotation displacement of femoral head, while the three-dimensional method, such as spiral CT seems a better choice.