Rohner Dennis, Tay Andrew, Meng Chung Sew, Hutmacher Dietmar W, Hammer Beat
Department of Plastic Surgery, General Hospital, Singapore, Switzerland.
Plast Reconstr Surg. 2002 Nov;110(6):1463-71; discussion 1472-5. doi: 10.1097/01.PRS.0000029360.61857.AE.
The aims of this study were to determine the forces required for fracturing the intact orbitozygomatic complex and to evaluate the strength of the orbitozygomatic complex-fixation, especially with regard to the sphenozygomatic suture as a fixation point. In severe midfacial and panfacial fractures, the sphenozygomatic suture is routinely used in the authors' practice as a key site for fixation of the orbitozygomatic complex, thus establishing a stable outer frame as a basis for subsequent reconstruction. However, this has never been formally described, nor has it been biomechanically tested. Eight human cadaver heads were subjected to forces applied in a standard fashion to the orbitozygomatic complex on both sides (n = 16) using a servohydraulic testing machine. The force required to break the intact orbitozygomatic complex was measured on both sides. Subsequently, fracture patterns were noted and each orbitozygomatic complex (n = 16) was assigned to one of four groups: four-point fixation (zygomatic arch, frontozygomatic suture, infraorbital rim, zygomaticomaxillary buttress) using a 1.3/2.0-mm titanium system (group 1) and a 2.0-mm bioresorbable system (group 3); or three-point fixation (zygomatic arch, frontozygomatic suture, sphenozygomatic suture) using 1.3/2.0-mm titanium system (group 2) and a 2.0-mm bioresorbable system (group 4). Forces for failure of the constructs were measured. The force for failure of the intact orbitozygomatic complex was 1826 +/- 852 N. The mean force required for failure of the reconstructed orbitozygomatic complex was 504 +/- 178 N for group 1, 620 +/- 304 N for group 2, 93 +/- 22 N for group 3, and 133 +/- 31 N for group 4. The titanium constructs provided 27.7 percent (four-point fixation) and 31.7 percent (three-point fixation) of the intact breaking strength of the orbitozygomatic complex, which was significantly higher (p < 0.05) compared with 5.4 percent (four-point fixation) and 7.7 percent (four-point fixation) for the bioresorbable system. Plate bending (91 percent) was the primary cause for failure in the titanium plating system, whereas plate and screw breakage (57 percent) was responsible for failure of the resorbable system. The fixation of the sphenozygomatic suture was a key site in the fixation of the orbitozygomatic complex, which could be demonstrated with superior results in the three-point fixation group compared with the four-point fixation group. The bioresorbable system showed the lowest values in this cadaver study. Further experimental and clinical studies might determine whether the bioresorbable materials are sufficient for the treatment of complex fractures of the orbitozygomatic complex.
本研究的目的是确定使完整的眶颧复合体骨折所需的力量，并评估眶颧复合体固定的强度，尤其是将蝶颧缝作为固定点的情况。在严重的面中部和全面部骨折中，蝶颧缝在作者的临床实践中常被用作眶颧复合体固定的关键部位，从而建立一个稳定的外框架作为后续重建的基础。然而，这从未被正式描述过，也未进行过生物力学测试。使用伺服液压试验机，以标准方式对8个人类尸体头部两侧的眶颧复合体施加力（n = 16）。测量两侧完整眶颧复合体骨折所需的力量。随后，记录骨折模式，并将每个眶颧复合体（n = 16）分为四组之一：使用1.3/2.0毫米钛系统（第1组）和2.0毫米生物可吸收系统（第3组）进行四点固定（颧弓、额颧缝、眶下缘、颧上颌支柱）；或使用1.3/2.0毫米钛系统（第2组）和2.0毫米生物可吸收系统（第4组）进行三点固定（颧弓、额颧缝、蝶颧缝）。测量构建物失效所需的力量。完整眶颧复合体失效的力量为1826±852 N。重建眶颧复合体失效所需的平均力量，第1组为504±178 N，第2组为620±304 N，第3组为93±22 N，第4组为133±31 N。钛构建物提供了眶颧复合体完整断裂强度的27.7%（四点固定）和31.7%（三点固定），与生物可吸收系统的5.4%（四点固定）和7.7%（四点固定）相比，显著更高（p < 0.05）。钢板弯曲（91%）是钛板固定系统失效的主要原因，而钢板和螺钉断裂（57%）是可吸收系统失效的原因。蝶颧缝的固定是眶颧复合体固定的关键部位，与四点固定组相比，三点固定组的效果更佳。在本尸体研究中，生物可吸收系统的值最低。进一步的实验和临床研究可能会确定生物可吸收材料是否足以治疗眶颧复合体的复杂骨折。
