I had a total knee replacement. Will I be able to pack trekking poles in my carry on bag?

If you’re tracking poles, have a point on the end I don’t think even a note from your doctor it will work. You would have to be using them at that point. I’ve been to potentially fly but putting them in your carry-on because you might need them when you get there probably isn’t going to work.

As has been said, poles with points are a no-no.
We both have mobility issues and so have bought, quite cheaply, adjustable folding walking sticks.. These would fit in your back pack, have a rubber ferrule, and adjust rto 38 inches tall - possible not as tall as a Nordic walking pole, but they work very well for two people at 5'10ins.

As Carol said, if your poles have a point on the ends, even if they are covered by a blunt rubber tip, they will not be allowed. You will need to check the bag. That's not the end of the world. Or as Lin C mentioned, buy ones that onlyhave the blunt tip.

As for modifications to your touring, related to your knee; that will vary completely from person to person. Everyone heals at different rates. Everyone's capacity to handle distances, uneven surfaces, stairs, and hills will be different. The best person to ask is your physiotherapist or surgeon. At 4 months I could only manage a mile on a fairly level smooth sidewalk. My neighbour was golfing 18 holes without a cart and biking 20 km at a time.

I travel a ton (I live internationally) and have ankle issues (have had surgery and will have an ankle replacement down the road). As others have said, trekking poles in carry on won't be allowed. Have you considered bringing a pair of crutches? Mine fold up and you can bring them in addition to your carry on. They've been handy for hikes/ long walks as well as while in the city. And four months post-surgery, they'll offer a lot more support than trekking poles will.

On another note, what modifications, if any, did you make during your travels to account for your still healing knee (I will be traveling at 4 months post surgery)? I'm grateful for any ideas!

This is not the same, but I tore my meniscus while traveling in Ireland last year. I was able to finish the trip with a good knee brace and crutches. It was a very supportive brace with hinges and it really helped keep my knee stable.

When I traveled later in the year after four months of PT, I brought a good supply of Alleve and the knee brace. I didn’t need to use the brace on that trip. I’m planning on bringing a supportive knee sleeve on future trips just in case I need it.

Always check official sites
https://www.tsa.gov/travel/security-screening/whatcanibring/items/hiking-poles
Blunt tips, yes
Sharp tips, NO

I too was worried about traveling after my knee replacements. I had to travel at 5 weeks post op, but just a 2 hour flight. Still just not being at home made me nervous but I was fine with a cane. Then we went to Iceland and Amsterdam at 4 months post op and had no issues whatsoever. I did not need a cane or any pain meds, not even Tylenol. I had the other knee done just a couple weeks after we got home. I know everyone’s recovery is different but I share mine to give you some encouragement.

I have also travelled long haul about 4 months after a knee replacement. I was warned to move about during the flight and to wear flight socks (apparently one is still at risk for blood clots). The flight and walking around generally were ok, but I found the aftermath of the flight and the travel itself much more exhausting than I normally would, so perhaps be aware of pacing yourself in case they affect you too?

My husband has folding hiking poles he uses as walking sticks. Wr fold them and put them in his backpack and have not had any problems.

This doesn't address your specific question, but maybe it will help folks avoid the mistake I recently made.

I have a terrific set of hiking poles. They, however do not even fold into a medium suitcase. We recently traveled to Australia and flew carry on size bag only, which I checked because of Jetstar's luggage limits. I purchased poles that folded smaller from Amazon. When I tried to use them in Australia, we couldn't get them to stay fixed once unfolded. My husband is an avid camper/backpacker, so he has experience, but neither of us could figure them out, so I didn't have poles to use. I ended up not desperately needing them, but they would have helped.

My husband's most helpful comment was, "equipment should always be tested before traveling". Well, he was a Boy Scout, I was not!! The poles are likely defective, and past the return time limit. I just got the idea that I should take them into REI, where we are members and frequent customers and see if they can determine the issue.

As another aside, I also have "funky knees", though I do a lot of hiking. I decided I didn't need them for the short to mid range hikes we planned for Hawaii. Well, it has been raining there, A LOT!! After a few days closure, the trail on the Napali coast did open but there were a few muddy slick areas. I fell, badly. Another hiker insisted I use his pole for the rest of the hike. It made a huge difference and I don't think I'll be hiking again without poles!

@Jules....excellent advice from your husband. We've got several sets of poles around the house. There is one set that needs to be thrown away because it does not always stay extended so I know exactly what you mean. We just need to pitch them out as soon as we come in from attempting to use them otherwise we forget which ones they are.

And yes, REI might be able to troubleshoot for you.

After I busted up my knee and had metal put in, I needed some type of support, at least on occasion.

I have routinely traveled with a pair of hiking poles, either using one and one in my carry-on, or both in my carry-on.

The set I have (I bought in Germany) fold down to less than 16", and have a flat carbide tip that will grip in rock, plus a rubber cap for street walking.

TSA does allow the blunt tip poles, especially if they are a walking aid. Of course, any final decision is up to the individual agents.

While not this brand, my poles (and the tip) are similar to these: https://www.dickssportinggoods.com/p/quest-cork-folding-trekking-poles-23queucrkfldngtrkcac/23queucrkfldngtrkcac?sku=24039812&camp=CSE:DSG_2385384643675_pla_pla-2385384643675_139387230222_18513991327&segment=&gclsrc=aw.ds&gad_source=1&gad_campaignid=18513991327&gbraid=0AAAAADv4bTZI-HrzJ1HnWdCg3PTnU70I7&gclid=Cj0KCQjw7IjOBhDyARIsAFzrWQwSI2wixucP4AU4IDnBT5HrGawJKmWVhF7EMnaJI0nn8vcF2Xi-cLMaAvLoEALw_wcB

Note this important statement on TSA website regarding blunt tip poles:

The final decision rests with the TSA officer on whether an item is
allowed through the checkpoint.

You could have the bluntest of blunt poles but the agent decides what passes through. No doctor note will help you there. Instead of worrying about yours being confiscated, consider purchasing an inexpensive pair when you arrive in Germany. Decathlon is an often mentioned store that carries outdoor equipment.

And of other modifications, bring several sturdy ziplock bags to use as ice packs along with whatever pain reliever works best for you. If that happens to be a highly regulated med like an opioid, be sure to keep in original container and bring your written Rx.

@Pam, yes, but perhaps selected a different moment to provide his opinion!

Recent discussion on hiking poles in carry-on bags

https://community.ricksteves.com/travel-forum/beyond-europe/hiking-poles-6cb450c7-1e1f-4a78-8f8f-2ddd289c5b80

Thanks to all of you for your suggestions!

Maureen,
Just a hopeful note....at four months post-surgery you may do better than you think. Of course, be prepared, but with each of my TKRs (done a year and a half apart) I was walking pretty well after 4 months, and although the swelling may take a good year to go down, the pain lets up way before that. You may only need Tylenol by 4 months and, except for stairs, your walking may be quite good. Perhaps just a cane will suffice, for balance more than support. No problem taking a regular cane on the plane.
Everyone is different of course, but I hope your recovery is quick and full. In my case, I was very strict with myself about all the exercises the PT therapist gave me and I must say that they know their business. My knees were done at age 78 and 80, just fyi. Wew were in Provence, Paris and the Dordogne 7 months after my first surgery, so your 4 months is closer. My only real difficulties were the uphill trek to Castelnaud and getting out of the kayak after a ride on the Dordogne River. It wasn't a pretty sight! I will keep my fingers crossed for you that all goes well. Have hope!