Bone is made up of two different types of bone: cortical and trabecular. Trabecular bone, also called cancellous bone, makes up about 20% of the skeleton. Trabecular bone is found predominantly in the spine and at the ends of the long bones.
Rods and Plates
Trabecular bone is a network of connecting plates and rods aligned in a pattern that provides maximal strength. This arrangement provides a large bone surface for mineral exchange.
Effects of Bone Loss
Bone loss usually occurs more rapidly in trabecular bone than dense cortical bone. The plates and rods thin or may even break with bone loss creating porous, fragile bone that is more susceptible to fracture.
Skeletal sites rich in trabecular bone like the spine also show the greatest response to treatment with osteoporosis medicines. Typically, your lumbar spine bone mineral density (BMD) on a DXA scan will increase more than your total hip, which contains more cortical bone.