TY - DATA T1 - Isolated metaphyseal injury influences unrelated bones PY - 2017/01/27 AU - Love Tätting AU - Olof Sandberg AU - Magnus Bernhardsson AU - Jan Ernerudh AU - Per Aspenberg UR - https://tandf.figshare.com/articles/journal_contribution/Isolated_metaphyseal_injury_influences_unrelated_bones/4591624 DO - 10.6084/m9.figshare.4591624.v1 L4 - https://ndownloader.figshare.com/files/7432141 KW - Isolated metaphyseal injury influences KW - untraumatized control animals KW - cell populations KW - contralateral tibia N2 - Background and purpose — Fracture healing involves different inflammatory cells, some of which are not part of the traditional bone field, such as B-cells and cytotoxic T-cells. We wanted to characterize bone healing by flow cytometry using 15 different inflammatory cell markers in a mouse model of metaphyseal injury, and incidentally discovered a previously unknown general skeletal reaction to trauma. Material and methods — A bent needle was inserted and twisted to traumatize the cancellous bone in the proximal tibia of C57/Bl6 female mice. This is known to induce vivid bone formation locally in the marrow compartment. Cells were harvested from the injured region, the uninjured contralateral tibia, and the humerus. The compositions of the immune cell populations were compared to those in untraumatized control animals. Results — Tibial metaphyseal injury led to substantial changes in the cell populations over time. Unexpectedly, similar changes were also seen in the contralateral tibia and in the humerus, despite the lack of local trauma. Most leukocyte subsets were affected by this generalized reaction. Interpretation — A relatively small degree of injury to the proximal tibia led to systemic changes in the immune cell populations in the marrow of unrelated bones, and probably in the entire skeleton. The few changes that were specific for the injury site appeared to relate to modulatory functions. ER -