Indomethacin Impares Fracture Healing in Mice


Anti-inflammatory treatment increases angiogenesis during early fracture healing.

Both inflammation and angiogenesis are crucial for normal fracture healing. The goal of this work was to determine how anti-inflammatory treatment affects angiogenesis during early stages of fracture repair.
Tibia fractures were created in adult mice and animals were treated with indomethacin (2 mg/kg/day), a non-steroidal anti-inflammatory drug, or PBS once a day beginning from 1 day before fracture and continuing to 6 days after fracture. Animals were killed at 7, 14, and 28 days after injury for histomorphometric analysis of fracture healing. A second group of animals were killed at 3 and 7 days after injury to measure tissue levels of VEGF and interleukin-1 beta (IL-1β). A third group of animals were killed at 3 and 7 days after injury for stereology analysis of macrophage and neutrophil infiltration and tissue vascularization.
Indomethacin significantly decreased bone and cartilage formation at 7 days after fracture compared to controls. Indomethacin decreased the tissue levels of IL-1β at 3 days after fracture but did not affect the recruitment of macrophages or neutrophils to injured limbs. Indomethacin-treated fractures had similar length density and surface density of vasculature as the controls at 3 days after injury. At 7 days after fracture, vasculature in indomethacin-treated fractures exhibited higher length density and surface density than that in controls. By 28 days after injury, indomethacin-treated fractures still exhibited defects in fracture repair.
Anti-inflammatory treatments using indomethacin impair bone and cartilage formation and increase tissue vascularization in the callus during early fracture healing.

Lu C, Xing Z, Wang X, Mao J…
Arch Orthop Trauma Surg Aug 2012
PMID: 22622792