Establishing a new rat model to investigate pathophysiology and bone healing in posttraumatic lymphedema

Posttraumatic lymphedema is a common complication after open and closed fractures with soft tissue trauma. Even though there is quite certain consensus about the basic mechanisms of lymphedema formation, the pathophysiology on a cellular and molecular base is largely unknown. Furthermore, there is currently no data on the interaction of lymphedema and bone regeneration. Subsequently, the aim of this study was to establish an animal model specific to posttraumatic lymphedema, which can be used to conduct future investigations into the pathophysiology and bone regeneration in lymphedema.

The test animals (rats)In wild-type Fisher 344 rats were divided into three groups: group one had an isolated bone defect, group two had an isolated soft tissue defect, and group three had a combination of bone and soft tissue trauma.

Using volumetric and circumferential measurements, a significant increase in circumference and volume in the sense of lymphedema could be detected, particularly 3-4 weeks after trauma in the groups with soft tissue trauma, whereas the creation of a bony defect did not appear to have a significant influence on the swelling. Microscopic images of the lymphatic drainage pathways verified the lymphatic drainage disorder weeks after soft tissue trauma.

Consequently, the established model can be used to investigate the exact pathophysiology of post-traumatic lymphedema. Furthermore, it seems to be suitable as a model for investigating bone regeneration in manifest lymphedema.