English to French Science Zoology bones

I need to translate the prase "internal brace system" in reference to an animal's bone. Here is the description I have:

"there are growths inside the bone that look like support beams; similar to flying buttresses inside a cathedral that keep the walls from buckling inwards. They’re arranged in particular directions and the direction shows you where the bone needed the most reinforcement, where it needed the biggest push from the inside to keep it from collapsing."

No problem to translate this part, but later in the text, the whole explanation is summed up as: "the bone's internal brace system".
I would like to know if there is a specific term for this phrase, or what would be the most accurate way to translate it.

Thanks!