These screw heads can break for many reasons. If the hardware was defective, you may have a product liability case. If the hardware was implanted improperly, there may be a malpractice case, although that is less likely. The specific facts are going to determine whether there is a case. We would need more information to give better advice. Texas has a 2 year statute of limitations, which probably runs from the sate of the surgery in the malpractice case, and from the date of the failure of the implant in the product liability case.