Division of Orthopedic Surgery, Rambam Health Care Campus, Haifa, Israel.
Division of Trauma, Santiago University Clinical Hospital, Musculoskeletal Pathology Group, Laboratory 18, Institute IDIS, Servicio Galego de Saúde, Santiago de Compostela, Spain.
Injury. 2021 Jun;52(6):1263-1270. doi: 10.1016/j.injury.2020.11.070. Epub 2020 Dec 31.
Interfragmentary compression, a major principle of fracture treatment, is clinically not quantified and might be lost quickly even without functional loads. We designed an experimental study hypothesizing that (1) compression can be controlled using either lag screw or compression plate, and expecting similar initial compression, (2) loss of interfragmentary compression through relaxation within one hour is reduced with neutralization locking plate next to lag screw compared to compression plate. Twelve ovine femora (N=6) and humeri (N=6) were assigned into groups: Group 1 received a 45° oblique osteotomy at mid-diaphysis and was fixated using a 3.5 mm interfragmentary lag screw and locking compression plate (3.5 mm LCP, DePuy Synthes) as neutralization plate. Group 2 received a transverse osteotomy and was fixated with dynamic compression using compression plate (LCP). Interfragmentary pressure and relative bone fragment displacements were recorded over one hour. Median loss of compression over one hour time (relaxation) were 0.52% in Group 1, and 0.17% in Group 2 (p>0.05). Median rotational displacements amounted to 0.46° for Group 1, and 0.31° for Group 2, and axial displacement to a median of -20 μm in Group 1 and 25 μm in Group 2. Ovine bone interfragmentary stress relaxation maintains compression over the first hour for lag screw with neutralization plate for an oblique fracture line or compression plate for a transverse fracture line. Measured compression forces around 100 N could be overcome by physiological tension loading in bending or torsion, necessitating for instance tension band plating, additional lag screws or absolutive stability.
骨间加压，骨折治疗的主要原则，临床上无法量化，即使没有功能负荷也会迅速丢失。我们设计了一项实验研究，假设：(1) 可以使用拉力螺钉或加压板控制加压，且预计初始加压相似；(2) 与加压板相比，拉力螺钉旁中和锁定接骨板可减少 1 小时内的骨间加压松弛。12 只绵羊股骨（N=6）和肱骨（N=6）被分配到以下组：组 1 在骨干中段接受 45°斜行切开，使用 3.5mm 骨间拉力螺钉和锁定加压板（3.5mm LCP，DePuy Synthes）作为中和板固定。组 2 接受横形切开，使用加压板（LCP）进行动力加压固定。在 1 小时内记录骨间压力和相对骨碎片位移。1 小时内的压缩损失中位数（松弛）在组 1 为 0.52%，在组 2 为 0.17%（p＞0.05）。组 1 的旋转位移中位数为 0.46°，组 2 为 0.31°，轴向位移在组 1 中为中位数-20μm，在组 2 中为 25μm。绵羊骨间加压应力松弛在斜行骨折线时使用带中和板的拉力螺钉或横行骨折线时使用加压板，可在最初 1 小时内维持加压。大约 100N 的压缩力可通过弯曲或扭转的生理张力负荷克服，这需要例如张力带钢板、附加的拉力螺钉或绝对稳定性。
