Paralytic osteoporosis

Bones stay strong partly because muscles pull on them and because they bear weight during standing and walking. When someone experiences paralysis, such as after a spinal cord injury, stroke, or severe nerve damage, the affected limbs no longer get this normal mechanical loading. Without that stimulus, bone breakdown starts to outpace bone building, and density drops, often faster than the bone loss seen with aging or menopause alone.

This process tends to be most noticeable in the legs and pelvis for people with lower-body paralysis, since those bones are the ones that normally bear the most weight. The bone loss can begin fairly soon after the injury and may continue for some time before leveling off. Because the bone becomes fragile, fractures can occur with very little force, sometimes during routine care like transfers, repositioning, or physical therapy.

Doctors may track bone density with scans and watch for risk factors like duration of immobility, extent of paralysis, and other health conditions. Treatment decisions, including whether medications or rehabilitation strategies are appropriate, belong to the treating physician, who will weigh the person's overall health, mobility goals, and fracture risk. Staying engaged with medical follow-up is especially important for anyone living with paralysis.