First and foremost, if you have not consulted a workers compensation attorney you should do so right away. It is unbelievable how many workers do not know all their rights under workers compensation and fail to pursue all of those rights. In your case, there could be such claims for temporary total disability, permanent partial disability, retraining benefits, loss of earning capacity among others.
Now as for your question. Under Wisconsin workers compensation law, workers compensation is the exclusive remedy for a workplace injury. However, if there was a safety violation that contributed to your work related injury you may have an additonal claim against the employer under workers compnesation law. If the injury was the cause of a party unrelated to the employer then you may be abl;e to sue that party, e.g., if a company sold a defective machine to the ER and the defectiveness of the machine contributed to the work related injury.
From experience, I can tell you that ER's and the workers compensation insurance carrier DO NOT usually have the EE's interests at heart. That is why you should consult with a work comp attorney. The usually send you to their doctor who is working for them, not you.
You probably cannot sue your employer for a work related injury you are limited to filing a WC claim withe the state agency in WC that regulates WC in your state.
THESE COMMENTS ARE NOT LEGAL ADVICE. They are provided for informational purposes only. Actual legal advice can only be provided after consultation by an attorney licensed in your jurisdiction. Answering this question does not create an attorney-client relationship or otherwise require further consultation.