If you have an injury or degenerative disease that caused you to be seriously hurt in a wreck that likely wouldn’t have injured someone else, your new pain was caused by the wreck. That means you’re entitled to compensation.
There is no legal fault in having a condition that makes an injury possible or more likely. This is known as the Eggshell Plaintiff Doctrine or Eggshell Skull Rule. It says that a defendant is liable for any injuries magnified by the victim’s pre-existing condition or characteristics such as herniated discs or osteoporosis.