Back in 2014, Megadeth's Dave Mustaine underwent spinal surgery, and even further back in 2002, Mustaine suffered severe radial nerve damage which extensively damaged his left arm. At the time, it was a big deal, as Mustaine and Megadeth were in the middle of playing Big Four shows with Metallica, Slayer and Anthrax, and Mustaine almost missed the NYC show, but due to God watching him, he made it through. He ended up cancelling a bunch of dates afterwards.
Citing the 2014 surgery, Mustaine tells South China Morning Post one of the hardest parts of the whole thing was not being able to head bang, and unfortunately the damage to his left hand is still very present.
"The hardest thing was not headbanging – I just do it without thinking,” he says. “You don’t know what it’s like to be in my body. There are some days when my left hand can’t even play. I don’t practise – I save it all for the tour."
That doesn't sound good. Hopefully Mustaine can get help with the arm in the future, unless he's eventually just going to be solely the frontman for the band? That, or hang it all up, which sucks.