移位股骨颈头下骨折模拟C臂X射线机观察闭合复位的真实精确性

Accuracy of closed reduction for displaced subcapital femoral neck fractures assisted by C-arm X-ray machine

背景:采用牵引床C臂X射线机下闭合复位、内固定治疗股骨颈头下骨折,可能有一定的误差。目的:模拟C臂X射线机下闭合复位透视分析骨折闭合复位的真实精确性。方法:直视下完全复位人工骨股骨颈头下骨折标本,使用克氏针固定。在股骨颈外侧,两个断端处分别使用克氏针打入,作为金属标志物。保持股骨颈标本、C臂X射线机位置不动,随后将股骨头分别顺时针、逆时针旋转15°,30°,再分别使用C臂机透视标准股骨颈正侧位,使用图像采集电脑工作站,采集图像。结果与结论:在股骨颈顺时针旋转15°、逆时针旋转15°时,股骨颈头下骨折两端皮质在正侧位透视下的移位差异无显著性意义,都有1mm左右移位。在股骨颈顺时针旋转30°、逆时针旋转30°时,股骨颈两端皮质在正侧位透视下的移位差异无显著性意义,都有2mm左右移位。表明使用C臂X射线机观察移位的股骨颈头下骨折,满足Garden指数复位要求,但不能判断出股骨头有无旋转,治疗移位的股骨颈头下骨折要切开复位。

BACKGROUND：Traction bed C-arm X-ray machine is used for closed reduction and internal fixation to treat femoral neck fracture has some errors.OBJECTIVE：To perspectively analyze the accuracy of closed reduction for femoral neck fractures by assisted C-arm X-ray machine.METHODS：Complete reduction of artificial femoral neck fractures was realized under direct vision and then fixed by kirschner pins which were knocked in at both fractured ends respectively on lateral femoral neck to be used as metal marker.Femoral neck specimens and C-arm X-ray machine were not removed and then the femoral neck specimens revolved 15° clockwise and 30° anticlockwise respectively.Anterior-posterior of the standard femoral neck was examined by C-arm X-ray machine,then corresponding imaging was collected.RESULTS AND CONCLUSION：There was no significant difference of the displacement in the both ends of the subcapital femoral neck fractures （around 1 mm both） when the necks were located at the position of 15°,30° clockwise and anticlockwise respectively.There was significant difference of the displacement in the both ends of the subcapital femoral neck fractures （around 2 mm both） when the necks were located at the position of 30°,30° clockwise and anticlockwise respectively.It is shown that C-arm X-ray machine is used to observe the subcapital femoral neck fractures and can meet the reduction requirement of Garden scores,but the femur head rotation cannot be identified.As a result,displaced femoral neck fractures necessitate open reduction.