Department of Orthopedics and Trauma Surgery, Medical Center - Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Germany; G.E.R.N. Tissue Replacement, Regeneration & Neogenesis, Department of Orthopedics and Trauma Surgery, Medical Center - Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Germany.
Department of Orthopedics and Trauma Surgery, Medical Center - Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Germany; G.E.R.N. Tissue Replacement, Regeneration & Neogenesis, Department of Orthopedics and Trauma Surgery, Medical Center - Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Germany.
Injury. 2020 Jun;51(6):1281-1287. doi: 10.1016/j.injury.2020.03.030. Epub 2020 Mar 17.
To date, surgically treated multifragmentary patellar fractures are still associated with high rates of complications, such as i.e. secondary fracture displacement. Osteosynthesis is most frequently performed with screws and cerclages. To increase primary stability, locking plates have been introduced. However, there is still a lack of biomechanical data supporting the superiority of plate fixation compared to screw fixation with cerclages in these cases. The goal of the present study was to conduct biomechanical comparison of these two techniques under dynamic loading conditions.
A standardized 34-C3 fracture was created in eight pairs of human cadaveric knee joints. Following a randomization protocol, they were fixed with a 3.5 mm anterior locking plate (LP) or cannulated screws with anterior tension band wiring (hybrid osteosynthesis, HO).Subsequently, all constructs were tested for 100 cycles from 90° of knee-flexion to full extension by applying a pulling force to the quadriceps tendon. Outcome parameters were fracture displacement after one cycle, after 100 cycles and implant loosening. Failure was defined as fracture displacement > 2 mm.
Biomechanical testing showed significantly less fracture displacement following LP compared to HO both after the first (p = 0.042) and after 100 cycles (p = 0.025). The difference in loosening was significant as well (p = 0.017). Following HO, 5/8 constructs failed during cyclic loading. There was no failure in the LP group. In the HO group, loosening correlated with bone mineral density (R = - 0.857) which was not observed in the LP group (R = - 0.429).
Anterior locking plate osteosynthesis of comminuted patellar fractures biomechanically provides better primary stability compared to cannulated screws with anterior tension band wiring.
迄今为止，手术治疗的多片段髌骨骨折仍然存在很高的并发症发生率，例如二次骨折移位。最常见的内固定方法是使用螺钉和环形钢丝。为了增加初始稳定性，已经引入了锁定钢板。然而，在这些情况下，与使用环形钢丝的螺钉固定相比，钢板固定的优越性仍然缺乏生物力学数据支持。本研究的目的是在动态加载条件下对这两种技术进行生物力学比较。
在 8 对人体尸体膝关节中创建了一个标准化的 34-C3 骨折。根据随机分组方案，使用 3.5mm 前锁定钢板（LP）或带前张力带钢丝的空心螺钉（混合骨合成，HO）进行固定。随后，所有构建体均通过向股四头肌肌腱施加拉力，从 90°膝关节屈曲到完全伸展进行 100 次循环测试。结果参数为一个循环后、100 次循环后和植入物松动的骨折移位。骨折位移>2mm 定义为失效。
生物力学测试显示，LP 组的骨折位移明显小于 HO 组，无论是在第一次（p=0.042）还是 100 次循环后（p=0.025）。松动的差异也很显著（p=0.017）。在 HO 组中，5/8 个构建体在循环加载过程中失效。LP 组没有失效。在 HO 组中，松动与骨矿物质密度相关（R=-0.857），而在 LP 组中则没有观察到这种相关性（R=-0.429）。
与空心螺钉加前张力带钢丝相比，粉碎性髌骨骨折的前侧锁定钢板内固定在生物力学上提供了更好的初始稳定性。
