Cortices is the plural form of Cortex.  Bone cortext would be the outer
layer, as opposed to the inner layer such as the marrow.  Thin bone
cortices are not the same thing as osteoporosis, although I wouldn't call
them a good thing.  I'm not aware of anything showing a high degree of
critical hip fractures or spinal deformity, which are commonly observable
in those suffering from osteoporosis.   Of course the Inuit's shorter
lifespans would have something to do with that, though Stefansson indicated
that it was not unusual for Inuit to live into their 60s.

A high degree of compression fractures isn't particularly meaningful unless
we can compare it to the rate for other hunter/gatherer peoples.
Compression fractures can be caused by a rough lifestyle (high school
football players get them all the time; I got one myself a few years ago
from a hard fall on my butt that also cracked my tailbone) and I would
expect them to be somewhat common among any people whose existence was so
dependent upon hunting with spears and fishing stuff out of holes in ice.

I am not entirely sure what to make of Staffan's references.  I obviously
need to read them.