Perry Kevin, Chauvin Brad, Daily Drayton, Kee Clarence J, Morandi Massimo Max, Barton R Shane, O'Neal Patrick, Saffell Bryan, Dewitt Cole, Cranford Luke, Solitro Giovanni F
Department of Orthopaedic Surgery, Louisiana State University Health Science Center-Shreveport, Shreveport LA, United States.
Department of Engineering and Science, Louisiana Tech University, Shreveport LA, United States.
Orthop Traumatol Surg Res. 2022 Jun;108(4):103273. doi: 10.1016/j.otsr.2022.103273. Epub 2022 Mar 21.
Pelvic internal fixation has become a popular method for treatment of unstable pelvic ring injuries. Although successful, one complication is femoral nerve palsy from compression of the connecting rod. In light of this complication, this study was designed to evaluate sagittal inclinations of the rod and the feasibility of using a rod with a constant curvature.
It is hypothesized that that there is a connection between the sagittal inclination of the rod and the rod to bone distance, as well as single rod can be contoured with a constant curvature to be used in the majority of all patients.
Three dimensional models of pelvis CTs from a single level 1 trauma center were created and imported into a program where software superimposed a pre-contoured rod in the sagittal planes upon the pelvic slices. The sagittal inclination was deemed acceptable is no interference occurred between the area of compression risk and the rod. For each pelvis and considered sagittal rod inclination, the rod radius of curvature (ROC), minimal rod to bone distance (RTB) and transverse inclinations (φ and φ) were measured at which the pedicle screws should be inserted to follow the direction of the smallest RTB.
The sagittal inclinations feasible for all subjects were between 15° to 30°. In this sagittal range, the average RTB varied in values ranging from 4.0±0.9mm to 25.4±11.4mm (p<0.01). Only 46% of subjects allowed a rod with constant curvature.
Our study found that a rod to bone distance of 15mm was not safe for all models. As well, many subject models did not allow placement of pre-contoured rod. Patient specific templating of pelvic subcutaneous internal fixation is strictly needed to limit complications.
VII; Basic Science.
骨盆内固定已成为治疗不稳定骨盆环损伤的常用方法。尽管手术成功，但一个并发症是连杆压迫导致股神经麻痹。鉴于这一并发症，本研究旨在评估连杆的矢状倾斜度以及使用具有恒定曲率连杆的可行性。
假设连杆的矢状倾斜度与连杆到骨的距离之间存在关联，并且单根连杆可以通过恒定曲率塑形以用于大多数患者。
创建了来自单个一级创伤中心的骨盆CT三维模型，并导入到一个程序中，该软件在骨盆切片的矢状平面上叠加一个预塑形的连杆。如果在受压风险区域和连杆之间没有发生干涉，则矢状倾斜度被认为是可接受的。对于每个骨盆和考虑的矢状连杆倾斜度，测量连杆的曲率半径（ROC）、连杆到骨的最小距离（RTB）以及椎弓根螺钉应插入的横向倾斜度（φ和φ），以遵循最小RTB的方向。
所有受试者可行的矢状倾斜度在15°至30°之间。在此矢状范围内，平均RTB值在4.0±0.9mm至25.4±11.4mm之间变化（p<0.01）。只有46%的受试者允许使用具有恒定曲率的连杆。
我们的研究发现，对于所有模型，15mm的连杆到骨距离并不安全。此外，许多受试者模型不允许放置预塑形的连杆。严格需要针对患者的骨盆皮下内固定模板来限制并发症。
VII；基础科学。
