Development of a femoral non-union model in the mouse.
OBJECTIVE
Advancements in our knowledge of fracture healing have occurred in large part by the understanding of this process on a microscopic level. The ability to develop experimental non-union models in animals will assist in the investigation of this problem and are likely to lead to novel treatments. We report on a technique for developing experimental non-unions in mice.


METHODS
Femoral fractures were created in 48 CD1 mice, 24 mice underwent standard closed femoral fractures, and 24 mice underwent creation of a femoral non-union through an open osteotomy and fracture devascularisation method. All fractures were subsequently rodded. Histological examinations of the fractures were then conducted at eight time points post-operatively.


RESULTS
The control group showed normal fracture healing with histological evidence of bony fracture bridging by 28 days and mature bony remodelling at 63 days. The non-union group showed delayed fracture healing at all time points and no evidence of bony healing at 63 days.


CONCLUSIONS
This is the first report of a reliable method to develop fracture non-union in mice. We believe this technique will be critical to further the investigation of fracture non-union in normal mice and provides the great advantage of using the plethora of transgenic and knockout mouse models to analyse non-union at the cell and molecular level.
Oetgen
Matthew E
ME
Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT 06520-8071, United States. Matthew.oetgen@yale.edu
Merrell
Greg A
GA
Troiano
Nancy W
NW
Horowitz
Mark C
MC
Kacena
Melissa A
MA
D000818:Animals; D016723:Bone Remodeling; D004195:Disease Models, Animal; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology / Q000601:surgery; D017102:Fracture Healing; D005599:Fractures, Ununited / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D051379:Mice; D010027:Osteotomy; D011859:Radiography