An experimental rat model allowing controlled delivery of substances to evaluate fracture healing.

We present a method to study the in vivo delivery of any substance in a rat femur fracture model that allows precise administration with control of both substance dosage and temporal application in a reproducible and predictable manner. This method is easy to perform, requires no expensive materials, and provides the benefit of internal stabilization of the femur fracture. In this model, all wounds are closed after surgery with no external ports or catheters, significantly reducing the infection rate and the risk of dislodgement due to animal intervention. This model allows the study of different substances given at different times in the same animal, providing the potential to improve our understanding of the interactions of various substances on normal fracture healing.