Glucocorticoids inhibit shaft XXXX healing but not metaphyseal bone regeneration under stable mechanical conditions.

@entity32 @entity619 @entity174
OBJECTIVES: Healing in cancellous metaphyseal bone might be different from midshaft @entity174 healing due to different access to mesenchymal stem cells, and because metaphyseal bone often heals without a cartilaginous phase. @entity32 plays an important role in the healing of a shaft @entity174 , but if metaphyseal injury is different, it is important to clarify if the role of @entity32 is also different. The biology of @entity174 healing is also influenced by the degree of mechanical stability. It is unclear if @entity32 interacts with stability-related factors. METHODS: We investigated the role of @entity32 in three different models: a metaphyseal screw pull-out, a shaft @entity174 with unstable nailing (IM-nail) and a stable external fixation (ExFix) model. For each, half of the animals received @entity619 to reduce @entity32 , and half received control injections. Mechanical and morphometric evaluation was used. RESULTS: As expected, @entity619 had a strong inhibitory effect on the healing of unstable, but also stable, shaft @entity174 . In contrast, @entity619 tended to increase the mechanical strength of metaphyseal bone regenerated under stable conditions. CONCLUSIONS: It seems that @entity619 has different effects on metaphyseal and diaphyseal bone healing. This could be explained by the different role of @entity32 at different sites of injury. Cite this article: Bone Joint Res 2015;4:170-175.
