An internal locking plate to study intramembranous bone healing in a mouse femur fracture model

Abstract

In most murine fracture models, the femur is stabilized by an intramedullary implant and heals predominantly through endochondral ossification. The aim of the present study was to establish a mouse model in which fractures heal intramembranously. Femur fractures of 16 SKH-mice were stabilized by an internal locking plate. Femur fractures of another 16 animals were stabilized by an intramedullary screw. Bone repair was analyzed by radiographic, biomechanical, and histological methods. At 2 weeks, histological analysis showed a significantly smaller callus diameter and callus area after locking plate fixation. Cartilage formation within the callus could only be observed after screw fixation, but not after fracture stabilization with the locking plate. Radiological and biomechanical analysis after 2 and 5 weeks showed a significantly improved healing and a higher bending stiffness of fractures stabilized by the locking plate. Fractures stabilized by the locking plate healed exclusively by intramembranous ossification, which is most probably a result of the anatomical reduction and stable fixation. The fractures that healed by intramembranous ossification showed an increased stiffness compared to fractures that healed by endochondral ossification. This model may be used to study molecular mechanisms of intramembranous bone healing. ß

In vivo gait analysis in a mouse femur fracture model

“…During the last few years, a considerable number of implants for fracture stabilization in mice have been developed, including locking nails (Holstein et al, 2007), intramedullary screws , locking plates (Histing et al, 2010), pinclip devices and external fixators (Cheung et al, 2003). Our results indicate that further studies are required to characterize the effect of these different osteosynthesis techniques on the mouse gait and motion pattern recovery.…”

Positive effect of tadalafil, a phosphodiesterase-5 inhibitor, on fracture healing in rat femur

“…[1][2][3][4][5] Because bone is highly vascularized, angiogenesis plays an extremely important role in bone formation during both bone development and fracture healing. [6,7] Previous studies have demonstrated that the angiogenic and osteogenic factors associated with the proteins of vascular endothelial growth factor (VEGF) and cysteine-rich 61 (CYR61) are involved in the process of fracture healing, [6][7][8][9] and that reduced vascularity at the fracture site is one of the most significant risk factors for delayed fracture healing.…”

Pseudofracture: An Acute Peripheral Tissue Trauma Model

“…[16][17][18][19][20][21] The challenge in experimental murine trauma modeling is long term investigation, as fracture fixation techniques in mice, can be complex and not easily reproducible. [22][23][24][25][26][27][28][29][30] This pseudofracture model, an easily reproduced trauma model, overcomes these difficulties by immunologically mimicking an extremity fracture environment, while allowing freedom of movement in the animals and long term survival without the continual, prolonged use of anaesthesia. The intent is to recreate the features of long bone fracture; injured muscle and soft tissue are exposed to damaged bone and bone marrow without breaking the native bone.…”