胫骨远端关节面穹隆前后置钉安全区的MRI测量

MRI measurement of the safety zone of anteroposterior screw placement in distal articular dome of the tibia

摘要:

[目的] 测量胫骨远端关节面穹隆前后置钉的安全高度和角度。[方法] 用医学影像浏览器测量100 例（男性组64例、女性组36 例） 踝关节MRI 矢状位T2 加权像上胫骨远端关节面穹隆顶点的软骨下骨与胫骨远端关节面前、后唇下缘连线的距离及胫骨远端关节面前唇弧形的切线与前、后唇连线的夹角。比较分析男女组、左右侧组的差别。[结果] 男性右侧关节面穹隆顶与前后唇连线距离显著高于女性，差异具有统计学意义[(5.6±0.9) mm vs (5.1±0.8) mm, P=0.035]。男性的左侧与右侧的前唇切线与前后唇连线夹角均低于女性，但差异无统计学意义（P＞0.05）。男性与女性中，左侧的关节面穹隆顶与前后唇连线距离均高于右侧，但差异无统计学意义（P＞0.05）。男性[(37.6±5.0)° vs (32.2±8.2)°, P=0.003] 和女性[(37.8±4.6)° vs (32.7±7.3)°, P=0.026] 的左侧的前唇切线与前后唇连线夹角均显著大于右侧。[结论] 踝关节远端前后向置入螺钉时，螺钉下缘应至少位于前唇边缘上方约7 mm，男性右侧高于女性右侧。如置入更远端螺钉，应向胫骨近端倾斜至少42°，男女性左侧均高于右侧。

Abstract:

[Objective] To measure the safe height and angle of anteroposterior screw placement in distal articular dome of the tibia.[Methods] The vertical distance of distal articular surface dome to the connecting line of the lowest point of the anterior and posterior tibiallips, and the angle between the tangent line of the anterior and posterior lips of the distal tibia were measured on the T2 weighted MRI imag-ines in 100 patients, including 64 males and 36 females. The differences between male and female groups and left and right groups werecompared and analyzed. [Results] The male had significantly greater vertical distance of distal articular surface dome to the connecting lineof the lowest point of the anterior and posterior tibial lips on the right side than the female, with statistically significant difference [(5.6±0.9)mm vs (5.1±0.8) mm, P=0.035]. The male had less angle between the tangent line of the anterior and posterior lips of the distal tibia on theleft and right sides than the female, but the difference was not statistically significant (P＞0.05). In both male and female, the vertical dis-tance of distal articular surface dome to the connecting line of the lowest point of the anterior and posterior tibial lips on the left side wasgreater than that on the right side, despite of the fact that difference was not statistically significant (P＞0.05). Both male [(37.6±5.0)° vs(32.2±8.2)°, P=0.003] and female [(37.8±4.6)° vs (32.7±7.3)°, P=0.026] had significantly greater angle between the tangent line of the ante-rior and posterior lips of the distal tibia on the left side and the right side. [Conclusion] As anteroposterior screw placement on the distaltibia, the lower edge of the screw should be at least 7 mm above the edge of the anterior lip of the tibia, which in male should be higher thanthat in the female on the right side. If further longer screws are implanted, tilting the screw at least 42° to the proximal tibia, with the leftside more tilting than the right side in both men and women.