For how long would a compression fracture of the spine take to heal for a very healthy 85 year old woman?

3 months. I usually recommend a brace when out of bed or kyphoplasty if the patient is in severe pain or not improving with time. Check out spine-health.Com.
While the pain can. Decrease, and the bones can heal, the compression of the vertebra does not normally occur. The wedge deformity that occurs from a compression fracture will usually remain until it is fixed with a vertebroplasty or surgically. Bracing can help a great deal.