As a patient with a pseudoarthrosis bends, the hardware rods and screws are also stressed back and forth, and they may eventually snap. This occurrence can turn into an emergency if the spinal hardware protrudes from the body or if it is in a position that is damaging muscles or nerves. Sometimes patients do not know that a piece of spinal hardware has broken, however, or that a screw or a hook has become loose and is moving in their backs. Virtually every spinal fusion utilizes autologous bone, self-donated by the patient from the hip or ribs during surgery. The mixing of the patient's own new and old bone results in a more dependably solid fusion.
Adults can even develop permanent slight lung impairment as a result of a thoracoplasty.
In addition, the use of autologous bone, whether from ribs or hips, increases the length of time of surgery and causes more blood loss, so it may not be desirable in certain populations of surgery patients, such as the older people. The surgeon may also choose to use bank bone if the patient has developed pain, unrelated to the spinal correction, in a previous bone donation site. There is reportedly no danger in contracting HIV, the virus that causes AIDs, or other diseases from bank bone.