title: Three-dimensional morphology of microdamage in peri-screw bone: a scanning electron microscopy of methylmethacrylate cast replica.
abstract: Screw implantation inevitably causes microdamage in surrounding bone. However, little is known about the detailed characteristics of microdamage in peri-screw bone. In this study, we developed a method to construct microdamage cast with methylmethacrylate (MMA) and observed the cast using scanning electron microscopy (SEM). In basic fuchsin stained bone sections observed by bright-field and fluorescence microscopy, diffuse damage, cross-hatched damage, and linear cracks were all presented in peri-screw bone. Using MMA casting/SEM method, we found numerous densely packed microcracks in the areas with diffuse damage. The osteocyte canaliculi and the microcracks consisting of diffuse damage had a similar diameter (or width), usually <0.5 μm, but their morphology was largely different. In the area with cross-hatched damage, the orientation of microcracks was similar to that in diffuse damage, but the number was significantly decreased. Many microcracks were thicker than 1 μm and associated with a rough surface. Large linear cracks (∼10 μm in diameter) occurred in different areas. Plenty of microcracks were present on the surface of some linear cracks. In conclusion, the MMA casting/SEM method can demonstrate the three-dimensional morphology of different types of microdamage, particularly the microcracks in diffuse damage, which are unable to be shown by light microscopy.
authors.affiliation: Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Department of Orthopedics, Shanghai Institute of Traumatology and Orthopedics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, PR              China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Jin
authors.initials: J
authors.lastname: Shao
authors.forename: Tingjun
authors.initials: T
authors.lastname: Ye
authors.forename: Lianfu
authors.initials: L
authors.lastname: Deng
authors.forename: Shijing
authors.initials: S
authors.lastname: Qiu
mesh_terms: D000818:Animals; D001863:Bone Screws; D002370:Casts, Surgical; D004285:Dogs; D005269:Femur / Q000293:injuries / Q000648:ultrastructure*; D021621:Imaging, Three-Dimensional; D020366:Methylmethacrylate; D008855:Microscopy, Electron, Scanning
chemical_list: D020366:Methylmethacrylate