title: An Intramedullary Locking Nail for Standardized Fixation of Femur Osteotomies to Analyze Normal and Defective Bone Healing in Mice.
abstract: Bone healing models are essential to the development of new therapeutic strategies for clinical fracture treatment. Furthermore, mouse models are becoming more commonly used in trauma research. They offer a large number of mutant strains and antibodies for the analysis of the molecular mechanisms behind the highly differentiated process of bone healing. To control the biomechanical environment, standardized and well-characterized osteosynthesis techniques are mandatory in mice. Here, we report on the design and use of an intramedullary nail to stabilize open femur osteotomies in mice. The nail, made of medical-grade stainless steel, provides high axial and rotational stiffness. The implant further allows the creation of defined, constant osteotomy gap sizes from 0.00 mm to 2.00 mm. Intramedullary locking nail stabilization of femur osteotomies with gap sizes of 0.00 mm and 0.25 mm result in adequate bone healing through endochondral and intramembranous ossification. Stabilization of femur osteotomies with a gap size of 2.00 mm results in atrophic non-union. Thus, the intramedullary locking nail can be used in healing and non-healing models. A further advantage of the use of the nail compared to other open bone healing models is the possibility to adequately fix bone substitutes and scaffolds in order to study the process of osseous integration. A disadvantage of the use of the intramedullary nail is the more invasive surgical procedure, inherent to all open procedures compared to closed models. A further disadvantage may be the induction of some damage to the intramedullary cavity, inherent to all intramedullary stabilization techniques compared to extramedullary stabilization procedures.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, Saarland University; tina.histing@uks.eu.
authors.forename: Tina
authors.initials: T
authors.lastname: Histing
authors.affiliation: Institute for Clinical & Experimental Surgery, Saarland University.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Menger
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, Saarland University.
authors.forename: Tim
authors.initials: T
authors.lastname: Pohlemann
authors.affiliation: RISystem AG.
authors.forename: Romano
authors.initials: R
authors.lastname: Matthys
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, Saarland University.
authors.forename: Tobias
authors.initials: T
authors.lastname: Fritz
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, Saarland University.
authors.forename: Patric
authors.initials: P
authors.lastname: Garcia
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, Saarland University.
authors.forename: Moritz
authors.initials: M
authors.lastname: Klein
mesh_terms: D000818:Animals; D005264:Femoral Fractures / Q000601:surgery; D005269:Femur / Q000601:surgery; D005593:Fracture Fixation, Internal; D005594:Fracture Fixation, Intramedullary; D017102:Fracture Healing; D051379:Mice; D010027:Osteotomy