Surgery to remove a screw in the very old may be too risky. In the ankle, plates and screws are customarily removed. Fixators and internal fixation devices are used also for some mid-bone fractures. The surgeon may graft bone to replace a missing segment that had to be surgically removed due to infection. Though dead tissue, cadaver bone provides a scaffold for living bone to grow into and remodel the graft.
Healing takes longer than with an autologous graft.
Another option is a substitute bone graft, fashioned with help from nonhuman substances. It derives from marine coral, whose spongy calcium structure resembles human cancellous bone. When these substitute grafts are placed next to healthy bone, the body remodels them in the same way it remodels human grafts. A bone filler paste now under investigation, however, is as strong as bone within 12 hours, according to a report of a study of patients whose wrist fractures were injected with the paste. Also under investigation are injections of growth factor proteins, such as morphogenic protein and transforming growth factor-beta, found naturally in the body in very small amounts.