I recently began wondering about Aizawa's amputation because I want to write about it. However, because I cannot be normal, that means I looked into more than I needed to, and I would like to share some of my (admittedly obvious) findings:
So when amputating his leg (below the joint), it was said to be a 'clean-cut' from the job of his knife. In medical terms, he had a traumatic 'guillotine-type' amputation. Which, by the way, is insane skill for him to do! His knife must've been sharp as hell AND had the force and swing to back it up, its no easy task to cut THROUGH bone (that's why there are bone saws in the medical field! I own a vintage one from WWII) The thing is, reattachment rates for these types of amputations is a high rate of success (around seventy to ninety percent) if done in the six to twenty-four time frame. This led me to question why Aizawa didn't reattach his limb.
In the world of advanced healing and quirks, reattachment that quick could be possible. Aizawa's injury would count as high priority due to how important the quirk erasure is, and the loss of blood. These types of amputations have low-risk of infection too due to no skin flaps and all layers being even with each other (not that this type of amputation doesn't get infected ever! Just lower than other (non)traumatic amputations). Of course, there would be downside of relearning your limb— reattachment/replantation isn't perfect— but that would happen regardless.
However, there are also many factors on why Aizawa couldn't get reattachment surgery (which is roughly a two-step surgery). Obviously, one being the quirk-destroying bullet. I am unsure how the quirk-destroying bullets work on a more technical level, but I am sure it's by entering the blood stream and being transferred to the quirk factor. Aizawa was hit by an original Shie Hassaikai bullet, so if it reached his quirk factor he would lose erasure forever. If a drug or any kind of infection is present in the amputation sight, reattachment is not possible due to the short time frame and the bloodstream not being cleared.
The drug would then be stagnant and stay in the severed limb as it is no longer connected to the liver or the kidneys. Which means, if Aizawa ate his severed limb like how I want him to, his limb cutting would be null and he would still lose his quirk. This obviously puts a damper on my plans, and now I am stumped and on the edge of there being a detox quirk for severed limbs only.














