Claes Lutz, Eckert-Hübner Kerstin, Augat Peter
Institute for Orthopaedic Research and Biomechanics, University of Ulm, Helmholtzstrasse 14, 89081 Ulm, Germany.
Langenbecks Arch Surg. 2003 Oct;388(5):316-22. doi: 10.1007/s00423-003-0396-0. Epub 2003 Sep 9.
Revascularization of a fracture depends on fracture stability and fracture gap conditions. The aim of the study was to determine quantitatively the revascularization and tissue differentiation in an animal model with different fracture gaps and controlled biomechanical conditions.
The study was performed on ten sheep with an osteotomy on the right metatarsal. The fracture was stabilized by an external fixator that allowed adjustable axial interfragmentary movement. Two groups of five sheep each were adjusted to a medium sized gap (M, 2.1 mm) and a large gap (L, 5.7 mm) under comparable interfragmentary strain (30-32%). The animals were killed after 9 weeks, and the metatarsals were prepared for undecalcified histology and analysis of tissue differentiation and vessel distribution.
Group M showed significantly more revascularization (M=1.62, L=0.85 vessels/mm2), more bone formation (M=37.2%, L=13.9%) and less fibrocartilage tissue (M=18.1%, L=39.1%) than group L. Larger vessels (>40 microm) were found mainly in the medullary channel, and smaller vessels (<20 microm) mainly in the peripheral callus. Histologically, group M showed partial bony bridging of the osteotomy gap, and the group L had delayed healing.
A good reduction of a fracture with small interfragmentary gaps is important for its revascularization and healing.
骨折的血管再生取决于骨折稳定性和骨折间隙情况。本研究的目的是在具有不同骨折间隙和可控生物力学条件的动物模型中定量测定血管再生和组织分化情况。
对10只右跖骨截骨的绵羊进行研究。骨折通过外固定器固定，该外固定器允许可调节的轴向骨折块间移动。在可比的骨折块间应变（30 - 32%）下，将两组各5只绵羊分别调整至中等大小间隙（M组，2.1毫米）和大间隙（L组，5.7毫米）。9周后处死动物，对跖骨进行不脱钙组织学处理并分析组织分化和血管分布。
与L组相比，M组显示出明显更多的血管再生（M组 = 1.62，L组 = 0.85条血管/平方毫米）、更多的骨形成（M组 = 37.2%，L组 = 13.9%）和更少的纤维软骨组织（M组 = 18.1%，L组 = 39.1%）。较大血管（>40微米）主要见于髓腔通道，较小血管（<20微米）主要见于外周骨痂。组织学上，M组显示截骨间隙有部分骨桥接，而L组愈合延迟。
骨折块间间隙小的良好复位对其血管再生和愈合很重要。
