I am hella weak for the JLA seeing Bruce take damage and shrug it off so often that they just straight up forget that said damage accumulates over time. He's one of their few (if, sometimes, only) regular human members. He doesn't have a healing factor or anything like that. He gets lucky. He works his ass off with three broken bones and a myriad of chronic wounds and pain. His medical chart is a mile long.
And the league only remembers this one day when they have to cart him back from a battlefield and he's been banged up pretty bad. They need to do more in depth diagnostic testing but the moment someone from the med team says anything related to an MRI Bruce has to be the one to stop them going "I have a multitude of metallic shrapnel inside my body, I can't do an MRI. You'll need to do a CT scan."
And he says this super nonchalantly. Like they should've already known about it. Hell, Bruce thought they did, because they're usually so nosy about his personal life otherwise. They would have, probably, if they hadn't been wearing those rose tinted glasses whenever seeing Bruce go to medical alone in prior instances of injury. He gets stabbed and shot all the time but gets back up so they just shrug it off in their heads. He's gotta be fine, right? Being told he's actually got a lot of spinal hardware and numerous injuries that have never quite healed right, and he's on chronic pain meds and physical therapy regimens for Life cleanly puts this into perspective for them.
Bonus points for any "we're stuck in this place for awhile" au's where Bruce is disconnected from his medications and goes into withdrawal plus the chronic agonizing pain returns. The league has never seen him like this before, and it scares the shit out of them. Because They Didn't Know (or, alternatively, Didn't Care To Know.)
