两种测量方法对Taylor外固定支架骨折复位精度的影响

Effect of two measurement methods on the accuracy of Taylor external fixator for fracture reduction

[目的]比较标准测量法和椭圆拟合测量法对Taylor外固定支架骨折复位精度的影响,以对胫腓骨骨折移位畸形进行精确矫正。[方法]将28根胫骨模型随机制造断裂以模仿胫骨骨折,利用基于Stewart平台的外固定支架(新中Taylor外固定器)对骨折模型进行固定,用同一固定相机拍摄全长标准正侧位照片以模拟X线片并导入软件(Trauma CAD,Coreldraw和word结合游标卡尺),分别采取标准测量法(标准法组)和椭圆拟合测量法(椭圆拟合法组)对模型的骨折移位参数进行测量并依次输入配套软件,根据电脑软件出具的电子处方,调节Taylor外固定支架上6根带刻度的螺杆进行复位,最后再次拍摄胫骨全长标准正侧位照片评估残留畸形程度。[结果]利用Trauma CAD,Corel Draw和Word三种软件对骨折模型进行标准测量结果差异均无统计学意义(P>0.05)。全部骨折模型对位对线良好,均达到功能复位标准。两组残留畸形相比,差异具有明显统计学意义(P<0.05)。同时,标准法组正侧位片位移、角度改善度分别为:89.97%、84.44%;91.18%、86.84%。椭圆拟合法组正侧位片中位移、角度改善度分别为:95.77%、88.66%;94.05%、90.04%。椭圆拟合法组复位效果优于标准法组。[结论]椭圆拟合测量法能精确定义Taylor外固定支架系统所需各项参数,对骨折畸形进行精确矫正,有利于骨折愈合及患肢功能恢复。

[Objective] To compare standard measurement versus ellipse fitting measurement for accurate assessment of reduction of tibia fracture with Taylor spatial frame, to correct the deformities of the tibiofibular fracture exactly. [Methods] Twenty-eight 3D printed plastic tibia bones were cut randomly in the middle and lower 1/3 to establish tibiofibular fracture mod- els. Firstly, make a solid fixation of those fracture models with Stewart platforms （Xinzhong ring fixator）. All the assembly of bone models and external fixators were checked by anteroposterior and lateral total length photos, then imported the images into related software including CorelDraw, Trauma CAD and Word combined with vernier caliper, to measure the remnant displace- ment with standard measurement （the control group） and ellipse fitting measurement （the trim group）. Finally, remnant displace- ment was imported into Xinzhong bounded software to calculating the digital prescription. Adjusting the length of the connected bar based on the prescription, taken anteroposterior and lateral tibial photos again to checking the reduction quality. [Re- suits] The standard measurement results of the fracture model were not statistically significant among Trauma CAD, CorelDraw and Word （P〉0.05）. The deformities were corrected well, to meet the standard of function restoration in all the 28 cases. How- ever, the residual displacement of standard measurement and ellipse fitting methods were statistically different （P〈0.05）. The standard measurement was significantly inferior to the ellipse fitting measurement in improved rates of mediolateral displace- ment （89.97% versus 95.77% P〈0.001）, anteroposterior displacement （91.15% versus 94.05%, P=0.032）, sagittal angulation （86.84% versus 90.04%, P=0.043） and coronal angulation （84.44% versus 88.66%, P=0.002）. [Conclusion] The application of ellipse fitting measurement can get the more accurate information needed by Taylor spatial frame to correct the deformities, which is beneficial to fracture healing and limb function recovery.