Nebel Dennis, Ferle Manuel, Schulz Thorben, Welke Bastian, Graulich Tilman, Decker Sebastian
Laboratory for Biomechanics and Biomaterials, Department of Orthopaedic Surgery, Hannover Medical School, DIAKOVERE Annastift, Anna-von-Borries Str. 1-7, 30625, Hanover, Germany.
Department of Ergonomics, Technical University of Munich, 85748, Garching, Munich, Germany.
Arch Orthop Trauma Surg. 2025 Jul 12;145(1):372. doi: 10.1007/s00402-025-05988-5.
Lumbopelvic fixation is commonly employed to stabilize unstable sacral fractures, particularly U-shaped (US) fractures, which may result in spinopelvic dissociation-leading to significant pain, deformity, and neurological deficits. Due to its superior biomechanical properties, lumbopelvic stabilization (LPS) has become the preferred method for managing such injuries. We aimed to compare the biomechanical stability of US-LPS with conventional LPS and bilateral iliosacral screw (ISS) fixation.
Six human cadaveric pelvic specimens were subjected to axial (750 N) and torsional (8 Nm) loading using a material testing machine (MTM). Seven configurations of LPS were evaluated. The range of motion (ROM) between three anatomical bony segments-the third lumbar vertebral body (LBV3), the first sacral vertebral body (SVB1), and the Crista Iliaca (CI)-was analyzed using an optical tracking system. Measurements included craniocaudal translation and anterior-posterior tilt under axial loading and internal-external rotation under torsional loading. Stiffness was calculated using force-displacement curves obtained via the MTM's integrated load cells and displacement transducers.
Both LPS and US-LPS configurations demonstrated reduced ROM and increased stiffness compared to ISS fixation under axial and torsional loading. US-LPS exhibited marginally greater stiffness than standard LPS. The use of additional cross-connectors in both LPS groups had minimal to no measurable impact on ROM or overall stability.
US-LPS offers slightly enhanced biomechanical stability over conventional LPS in the fixation of unstable US sacral fractures. In contrast, standalone ISS fixation did not improve stability compared to the unfixed condition in this cadaveric model.
腰骶部固定常用于稳定不稳定的骶骨骨折，尤其是U形骨折，这类骨折可能导致脊柱骨盆分离，进而引发严重疼痛、畸形和神经功能缺损。由于其优越的生物力学性能，腰骶部稳定术（LPS）已成为治疗此类损伤的首选方法。我们旨在比较U形骨折腰骶部稳定术（US-LPS）与传统LPS及双侧髂骶螺钉（ISS）固定的生物力学稳定性。
使用材料试验机（MTM）对6具人体尸体骨盆标本施加轴向（750 N）和扭转（8 Nm）载荷。评估了7种LPS构型。使用光学跟踪系统分析三个解剖学骨段——第三腰椎椎体（LBV3）、第一骶椎椎体（SVB1）和髂嵴（CI）之间的活动范围（ROM）。测量内容包括轴向载荷下的头尾平移和前后倾斜以及扭转载荷下的内外旋转。使用通过MTM的集成载荷传感器和位移传感器获得的力-位移曲线计算刚度。
在轴向和扭转载荷下，与ISS固定相比，LPS和US-LPS构型均显示ROM减小且刚度增加。US-LPS的刚度略高于标准LPS。两个LPS组中使用额外的横向连接器对ROM或整体稳定性的影响极小或无法测量。
在不稳定的U形骶骨骨折固定中，US-LPS比传统LPS具有略高的生物力学稳定性。相比之下，在这个尸体模型中，单独的ISS固定与未固定状态相比并未提高稳定性。
