Edmonds Eric W, Fuller Corey B, Jeffords Megan E, Farnsworth Christine L, Lindgren Amelia M, Pennock Andrew T, Upasani Vidyadhar V
Department of Orthopaedic Surgery, University of California, San Diego, USA.
Division of Orthopedics, Rady Children's Hospital, 3020 Children's Way, MC 5062, San Diego, CA, 92123, USA.
J Exp Orthop. 2020 Mar 4;7(1):9. doi: 10.1186/s40634-020-00227-9.
The purpose of this study was to assess the effect on femoral torsion by rotational osteotomies at three different levels as measured in 3D using both the mechanical and the anatomic axes.
Ten cadaveric lower extremities underwent femoral osteotomies perpendicular to the anatomic axis (AA) at three levels: subtrochanteric, mid-diaphyseal and supracondylar. Parallel pins were placed, one in each femur segment. Computed tomography (CT) was acquired in post-osteotomies neutral position, then post-external rotation of the femur at each osteotomy level. Femurs were returned to neutral rotation between imaging exams. Using 3D CT reconstructions, custom software calculated femoral torsion (angle between the femoral neck axis and the posterior condylar axis in the transverse plane) and pin angle between segments, reoriented to both the mechanical axis (MA) and the AA. Pin angle and torsion change were compared for the three osteotomy locations (regression analysis and ANOVA performed).
Two specimens were omitted (inadequate imaging); the remaining eight donors were 55-90 years old (mean: 64 ± 15 years), CT confirmed no bony defects. All three levels of osteotomy demonstrated significant correlations between the amount of rotation at the osteotomy (pin angle change) and the resulting change in femoral torsion (R square range 0.658-0.847). No significant differences were found between osteotomy level in torsion (MA:p = 0.285, AA:p = 0.156) or in pin angle (MA:p = 0.756, AA:p = 0.753).
Performing a corrective rotational osteotomy orthogonal to the AA achieves the desired effect on MA regardless of location. This suggests that a surgeon's osteotomy level choice may be based on other risks/benefits of the various techniques.
本研究的目的是通过在三个不同水平进行旋转截骨术，利用机械轴和解剖轴在三维空间中测量，评估其对股骨扭转的影响。
对10具尸体下肢在三个水平进行垂直于解剖轴（AA）的股骨截骨术：转子下、股骨干中段和髁上。在每个股骨节段放置平行针。截骨术后在中立位进行计算机断层扫描（CT），然后在每个截骨水平使股骨进行外旋后再次进行CT扫描。在两次成像检查之间将股骨恢复到中立旋转位。使用三维CT重建，定制软件计算股骨扭转（股骨颈轴与横断面上后髁轴之间的角度）以及节段间的针角度，并将其重新定向到机械轴（MA）和AA。比较三个截骨位置的针角度和扭转变化（进行回归分析和方差分析）。
排除两个标本（成像不足）；其余8名供体年龄在55 - 90岁之间（平均：64±15岁），CT证实无骨缺损。所有三个截骨水平均显示截骨处的旋转量（针角度变化）与股骨扭转的最终变化之间存在显著相关性（R平方范围为0.658 - 0.847）。在扭转方面（MA：p = 0.285，AA：p = 0.156）或针角度方面（MA：p = 0.756，AA：p = 0.753），截骨水平之间未发现显著差异。
无论位置如何，与AA正交进行矫正性旋转截骨术均可对MA产生预期效果。这表明外科医生对截骨水平的选择可能基于各种技术的其他风险/益处。
