I broke my right arm and have slight muscle (bicep) deformation.
In any kind of curl, my right arm always fails first. So, if doing alternating reps, I just stop working out my left arm once my right arm fails. I will continue doing this until they are on par again. Unless the muscles/tendons are severely injured, you should be able to return to proper, equal strength eventually. But it may take a long while, so be patient when working them and try to give the weaker part the same workout as the stronger part so you stay proportional.