Chances are that your former employer is not liable.   Several years ago, because perceived abuses in the worker's comp field, Texas placed a cap on what employees could recover as a result of work related injuries.  The changes were made even prior to your injury 19 years ago.  If your employer elected to participate in the worker's comp system, you would have received several different types of benefits, and possibly a payout claim.  Once those administrative remedies are exhausted they are gone.  You may have a chance depending on how your claim was resolved, if your employer opted out of the worker's comp system, and if there was a more serious level on negligence on the part of your employer.  Even assuming you can find a limited exception, the intervening injury is going to be another problem because you will have to show whether your continuing pain and suffering is a result of your work injury or the other injury.  Because some expections could apply to your situation under a limited set of facts, it would be worth a visit to a couple of personal injury attorneys to get a first and second opinion about the facts of your case.  Gather as much of your documentation as possible and have a person injury attorney review them.