Is it legal in Texas to drive with left hand cast?

It is generally not illegal to drive with a cast on your left hand in Texas, as long as you are able to safely operate the vehicle. Driving with a medical condition that could impair your ability to drive is generally discouraged, and it is your responsibility to ensure your safety and the safety of others on the road. In case of any doubt or concern about driving with a medical condition, it's advisable to consult with a physician and follow their recommendations.