Augat P, Margevicius K, Simon J, Wolf S, Suger G, Claes L
Department of Orthopaedic Research and Biomechanics, University of Ulm, Germany.
J Orthop Res. 1998 Jul;16(4):475-81. doi: 10.1002/jor.1100160413.
To characterize the site-specific mechanical and histological properties in fracture repair and to relate these properties to the initial mechanical situation, an experimental fracture model was used in the metatarsus of 42 sheep. The mechanical situation of a transverse osteotomy was described by three gap sizes (1, 2, or 6 mm) and two amounts of strain (7 or 31%). An external fixator that allowed a defined axial movement provided control of these settings. Nine weeks following surgery, the healing area was dissected and tensile and compressive properties were measured in subregions of the fracture gap and the periosteal callus. The central, sagittal section was used for quantitative histology. We found the quality of the tissue along the osteotomy line to be most important for regaining mechanical stability. Increasing the size of osteotomy gaps resulted in poorer mechanical and histological qualities, and the repair process was less complete. Interfragmentary strain did not significantly influence the repair process. The smaller strain levels had already stimulated the secondary repair process, and this stimulatory effect could not be further enhanced by increasing the amount of strain. Our finding that large gaps between bone segments were not as well healed as were smaller gaps suggests that it is advantageous to avoid large gaps in fracture treatment.
为了表征骨折修复中特定部位的力学和组织学特性，并将这些特性与初始力学情况相关联，在42只绵羊的跖骨上使用了一种实验性骨折模型。通过三种间隙尺寸（1、2或6毫米）和两种应变程度（7%或31%）来描述横向截骨的力学情况。一种允许进行特定轴向运动的外固定器实现了对这些设置的控制。术后九周，对愈合区域进行解剖，并在骨折间隙和骨膜骨痂的子区域测量拉伸和压缩特性。中央矢状切面用于定量组织学分析。我们发现沿截骨线的组织质量对于恢复力学稳定性最为重要。增加截骨间隙的尺寸会导致力学和组织学质量较差，且修复过程不太完整。骨折块间应变对修复过程没有显著影响。较小的应变水平已经刺激了二次修复过程，并且这种刺激作用不会因增加应变程度而进一步增强。我们的研究结果表明，骨段之间的大间隙不如小间隙愈合得好，这表明在骨折治疗中避免大间隙是有利的。
