Department for General, Trauma and Reconstructive Surgery, University Hospital LMU Munich, Munich, Germany.
StaBLab, Department of Statistics, Statistical Consulting Unit, LMU Munich, Munich, Germany.
Eur J Trauma Emerg Surg. 2022 Oct;48(5):3659-3667. doi: 10.1007/s00068-020-01566-z. Epub 2021 Jan 2.
Intramedullar nailing of tibial mid-shaft fractures is a common surgical treatment. Fracture reduction, however, remains challenging and maltorsion is a common discrepancy which aggravates functional impairment of gait and stability. The use of radiographic tools such as the cortical step sign (CSS) and the diameter difference sign (DDS) could improve fracture reduction. Therefore, the validity of the CSS and DDS was analyzed to facilitate detection of maltorsion in tibial mid-shaft fractures.
Tibial mid-shaft fractures were induced in human cadaveric tibiae according to the AO classification type A3. Torsional discrepancies from 0° to 30° in-/external direction were enforced after intramedullary nailing. Fluoroscopic-guided fracture reduction was assessed in two planes via analysis of the medical cortical thickness (MCT), lateral cortical thickness (LCT), tibial diameter (TD), anterior cortical thickness (ACT), posterior cortical thickness (PCT) and the transverse diameter (TD) of the proximal and distal fracture fragment.
The TD, LCT and ACT have shown a highly significant correlation to predict tibial maltorsion. While a model combining ACT, LCT, PCT and TD lateral was most suitable model to identify tibial maltorsion, a torsional discrepancy of 15°was most reliably detected with use of the TD and ACT.
The present study has shown, that maltorsion can be reliably assessed by the CSS and DDS during fluoroscopy. Thus, torsional discrepancies in tibial mid-shaft fractures can be most reliably assessed in the lateral plane by analysis of the LCT and TD.
髓内钉治疗胫骨中段骨折是一种常见的手术治疗方法。然而，骨折复位仍然具有挑战性，扭转畸形是一种常见的差异，会加重步态和稳定性的功能障碍。使用皮质阶跃征（CSS）和直径差征（DDS）等影像学工具可以改善骨折复位。因此，分析 CSS 和 DDS 的有效性，以帮助检测胫骨中段骨折的扭转畸形。
根据 AO 分类 A3 型，在人体尸体胫骨中诱导胫骨中段骨折。在髓内钉固定后，施加 0°至 30°内/外扭转差异。通过分析医学皮质厚度（MCT）、外侧皮质厚度（LCT）、胫骨直径（TD）、前皮质厚度（ACT）、后皮质厚度（PCT）和近端和远端骨折碎片的横径（TD），在两个平面上进行透视引导下的骨折复位评估。
TD、LCT 和 ACT 与预测胫骨扭转畸形具有高度显著相关性。虽然结合 ACT、LCT、PCT 和 TD 外侧的模型是识别胫骨扭转畸形最合适的模型，但使用 TD 和 ACT 可以最可靠地检测到 15°的扭转差异。
本研究表明，CSS 和 DDS 可在透视术中可靠地评估扭转畸形。因此，通过分析 LCT 和 TD 可以最可靠地在侧位评估胫骨中段骨折的扭转差异。
