US employers like controlling our health insurance, because it makes us dependent on them for survival, giving them lots of leverage. But repetitive strain injuries like carpal tunnel, and other neck, shoulder, hand, and arm injuries that are costly to treat are [workplace injuries](https://www.nhs.uk/conditions/repetitive-strain-injury-rsi/). That means your employer should be paying for medical treatment for your injury as a [workers compensation claim]( Workers' Comp for Repetitive Strain or Stress Injuries (mycomplawyers.com)). Any adverse action taken against a worker for making a workers compensation claim is typically actionable, depending on your State's law, as illegal retaliation.
Don't spend your wages on healthcare your employer should be providing.