Screws and metal plates are used to hold a bone together after a fracture until healing takes place. There usually isn’t a joint involved and no motion at that site occurs.
In the spine, screws will hold the bones steady and reduce motion. However, studies show that this is only a partial fix. Motion is still possible because there are several joints that give the spine movement in the same area where the screws are placed.
Too much stress or load on the screw can cause it to break off or the bone to fracture. Sometimes, the screws “migrate” or move from where they are placed. This causes even more problems. Screws can be used on a trial basis for a week to see if relief from painful symptoms is possible. After the trial, the screws are removed and a fusion is done.