Yes, this is real, although I haven't personally experienced it. You can try searching for the phrases "surgically-induced neuropathic pain" or "post-surgical neuropathy". And chronic pain of any sort makes it hard to think clearly and can impact your personality, which you would notice, as his partner. If both his surgeon and his primary care doctor are at a loss, consider asking for a referral to a pain clinic or a neurologist who specializes in neuropathies. With any sort of chronic pain, the longer it goes untreated, the greater the risk that it will become harder to treat. So if you get a referral but the next available appointment won't be for several months, it's worth asking if you can get on a waitlist for an earlier appointment if one opens up -- you may have to change your plans on the fly because it will be short notice, but it will be worth it.