Table 1.
The variables for outcome assessment.
Figure 1.
Microdamage in peri-screw bone stained with basic fuchsin.
Diffuse damage was contacted with bone edge (large arrow), behind which larger linear cracks (small arrows) were visible. Linear cracks often mixed with diffuse damage (arrow heads) in the area adjacent to the bone-screw interface.
Table 2.
Comparison of microdamage related parameters in peri-screw bone between different time points after surgery.
Figure 2.
Resorption cavities in peri-screw bone (1 month after surgery).
A) cutting cavities (arrow) were covered by a thin layer of basic fuchsin stained tissue and contacted with microdamage; B) closing cavity (arrow) was covered by a thick seem of osteoid, on which there was a single layer of cuboidal osteoblasts attached.
Table 3.
Comparison of bone resorption related parameters in peri-screw bone between different time points after surgery.
Figure 3.
The distribution frequency of bone resorption cavities in different areas of peri-screw bone.
The distribution patterns were similar in 2-weeks, 1-month and 2-months groups. In the region of 500 µm from the bone-screw interface, about 40% of the resorption cavities were located in the area of <100 µm from bone edge.
Figure 4.
The morphology of microdamage and bone resorption cavities in peri-screw bone.
A) microdamage adjacent to the bone-screw interface was composed of diffuse damage and linear cracks (1 day after surgery). The microcracks not only cut through osteocyte lacunae and canaliculi in bone matrix, but also destroyed the surface of Haversian canal (arrows); B) cutting cavities (arrows) in damaged bone (2 weeks after surgery); C) closing cavities (arrows) in damaged bone (2 months after surgery). Extensive osteocyte lacunar-canalicular network was visible in newly formed bone beneath the osteoid (top arrow).
Figure 5.
Huge bone resorption cavities in the cross section of peri-screw bone.
A) irregular and bifurcated resorption cavity (arrow) in damaged bone; B) Huge resorption cavity (long arrow) with cutting zone (short arrow) in damaged bone and closing zone (arrow head) behind (1 month after surgery).