Setting: Modern Russia (or perhaps a bit in the future); United States (same time period)
Background: I have a character who was adopted from Russia by an American woman when he was a toddler. He is now an adult (mid-twenties), speaks fluent English and Russian (his mom enrolled him in Russian classes as a child, and he majored in it in college) and has a job that frequently has him traveling between the two countries. During one trip to Russia, he was able to locate his birth mother (I'm aware that Russian adoptions are closed, but it's possible; I've read accounts by people who have done it) and learned that he has a nephew (the mother was his half-sister) who is living at a local orphanage and is up for adoption.
After meeting and getting to know the child (he's somewhere in the 7-9 age range) he decides to adopt him. Now, single men aren't generally allowed to adopt in Russia, but there are extenuating circumstances (blood relation, approval of the birthmother, some powerful friends in the business/political world who are willing to pull some strings for him, etc.) and I think the scenario is at least plausible. The story isn't really focused on the legal aspects, anyway.
My question: The nephew is in need of some sort of surgery when he arrives in the U.S. I'm hoping for some sort of condition that he either would have been born with or would have developed shortly after birth, as I was planning on having my MC blame the condition for why his nephew wasn't adopted when he was little. I've considered something like strabismus, but I'd like it to be little more serious than that, if possible. It can't be for a life threatening condition or he probably wouldn't have survived for as long as he has, but I'd like for him to have at least a minor physical disability that can only be fixed with surgery. I'd also like it to be something that would not have severe long term affects after the surgery (e.g. no transplants because he'd need to be on immuno-suppressants for the rest of forever). Finally, it shouldn't be something that would affect his mental development; his mental health is as sound as it can be given the circumstances.
(Note: He does not have RAD or fetal alcohol syndrome. I'm aware that they're legit concerns in adopting older children from orphanages in real life, but they don't fit the story. I've also ruled out cleft palate for the same reason -- doesn't fit the story.)
I apologize if that's overly vague. I'm really open to anything, provided it fits the above restrictions. Even if someone can just point me in a direction to look, I'd be grateful. The only surgeries I can think of that children might need are for things like removing tonsils, which wouldn't be something he'd have had since he was a baby, or for really serious diseases such as cancer. Any suggestions?
Search terms I tried: "childhood surgery," "children and surgery," "childhood illness surgery," "surgery," "minor surgery," "minor surgery in children," and about a bajillion variations thereof. Most of the sites I've found are about preparing children for generic surgery, and don't include examples as to what they might be getting the surgery for. I've also searched "common russian genetic disorders," "russian adoption genetic disorders," etc. for ideas that might be specific to Russian orphans, but most of those websites only briefly mention genetic diseases (your child might have one, see a doctor if you have concerns) and then jump right into discussing RAD and other common PI problems.
Eta: Think I'm all set now. Thank you for everyone's ideas! :)