Walking boot for small fracture : Croatia trip

I've only been to a few of the places on your itinerary. I've never dealt with a broken bone at home much less on vacation, but I have badly sprained both ankles on a trip. That wasn't fun, but I pushed through it, and I was most certainly not pain-free. The biggest issue was the risk of reinjury, which did happen (I am a world-class klutz), no doubt significantly slowing my recovery. I'd be worried about dealing with cobblestones and unpaved surfaces (the Mljet forest sounds iffy), less so about smooth pavement.

When is your trip? Do you have time to test the situation at home for a while before you have to make a decision? I think at the very least you need to be prepared to peel off from the walking tours and move around more carefully and slowly on your own in some places.

Is this a stress fracture or some other kind?

Really, you need to speak to a doctor, not a bunch of travel enthusiasts.

The doctor is ok with me going
Yes, it is a stress fracture
If this was the US I would know what to expect

my question is Croatia specific. I don’t know the terrains, distances…
are cobblestone the standard surface in every location? or mainly Dubrovnik,?
are the surfaces such that I Could bring a kneeling scooter as back up ?

I can only tell you about a few of these places.
Dubrovnik- the stradun, main avenue is limestone. Either side you enter on is fine, the pile gate has a ramp or steps. You can get a feel for the city and walk around or scoot enough without going up and down all the steps. Don’t attempt walking around the wall. Ston is vey small city and their attraction is their wall - think Great Wall of China. Mostly stairs. Korcula you can get around. There is one main staircase to get into the old city, but all around is flat. You can see it on a webcam (I just google webcam Korcula. You can webcam many of these sights) I have been there 1/2 dozen times are am trying to remember if it is mostly cobblestone or limestone. Ugh. I will look at some of my pictures and update. Split is pretty flat and the main streets are limestone. If anyone remembers differently please let us know.

I was on a knee scooter for months. No, I would not take one on a trip. It is not that easy to use. Even a stair or two will mean someone has to lift it up. A cobblestone can cause it to tip or stop abruptly with potential of a fall. With a boot, you can get most any place even if slow. I assume you have a good boot that pumps up to give good support.

If you can get information--even incomplete--about where the walking tours will go, you can take a look at Google Maps' Satellite View. Zoom way in and drag the little yellow man to the streets you expect to traverse. You should be able to see what kind of surface the sidewalks have.

An acquaintance just returned from a similar cruise/Croatia trip. I know she stayed on board instead of an excursion at least one day.
If that's a possibility on your trip, maybe better than staying home another year?

Is this a group of friends or family going with you, cause I can then understand why you would want to go. These kind of trips are often not repeated. If you are going solo it would be difficult not having anyone to move slow with you or help along the way. It’s a tough call.

In 2015, I was boarding the aircraft when I found that I could not lift my right arm higher than my shoulder. I had fallen and caught myself. Turned out to be a rotator cuff tear. It didn't make the trip impossible, but I was much less capable.

In 2019, I fell 3 weeks before the trip and banged the ... out of my right knee. Again, took the trip. Pretty much limped through the entire thing. Definitely slowing and debilitating. Later that summer, I had a situation in which both hip joints became very inflamed and swollen. Finally got a couple doses of cortisol or something in each, and that fixed it.

What I would do is go for a long walk pretty soon. See what you think. Go up and down some steps. Carry your suitcase. Only you can decide how annoying this will be. And don't take a pain-killer before. That can mask your situation.

Sound like you are going on a small ship cruise of which we completed one in 2019.
I am including a link to my trip review of small ship cruising.
The walking will be constant and on a variety of surfaces.
On board you will encounter steps needed to board and ascend/descend between two and three levels to reach your cabins, dining area and sun deck. Most decks and stairs are hard surface and can become quite slippery when wet. Be Careful!
If you are booked on a lower deck you might inquire if an upper deck is available to avoid using stairs to your cabin.
Most small cruise ships dock adjacent to each other so going through the passages of one ship to another to access land will require the assistance of a fellow traveler. All decks are not at the same level and you also need to watch your head height to avoid going bump on your noggin.
In port you will encounter a variety of surface materials (cobblestone, concrete, pavers, etc) which are predominantly safe to navigate. We dealt with steps in every port in order to reach desired sites.
In my opinion you will definitely be hampered in ability to effectively visit these destinations and need to adjust your "walking time" to enjoy the experience.
Some thoughts......
1) stay hydrated starting the day prior to your visit as this time of year is quite hot. Hydration will assist with recovery time for your body
2) be okay with getting off your feet during port time to sit at an outdoor cafe, in the shade, and watch the world go by while taking a few drinks. Engage the servers to learn of nearby places to visit which may match your needs. Croatians are super friendly and willing to assist travelers.
3) Pace yourself so everyday can be enjoyed. Yep, your trip will be hindered BUT you are getting to travel and as RS believes you don't need to cover lots of geography to enjoy a great journey. Don't risk overdoing the first few days to where you are cabin bound recovering for the remainder fo the trip.
4) Croatian airports do not always offer gates connecting to the planes. Hence you will need to use stairs down to the tarmac, up and down the bus going to and from the plane, and then up and down stairs to the plane . Don't underestimate the amount of steps you will encounter.
5) This is the perfect trip to practice MINIMUM packing in order to Maximize your ability to get around.
6) get ahead of the daily pain by downing your favorite pain killer. Watch out for overcompensating your injured foot by over stressing your knees or other foot. Take your time walking and if you feel weary then take a break by getting off your feet.

Forthrightly if you could defer the trip then I would do so. There is so much to see in each of the locations you mentioned in your post. However, if you cannot, then please study YouTube videos for each destinations to gain a sense of what you value visiting and try to determine your priorities.

Be well!

https://community.ricksteves.com/travel-forum/trip-reports/a-small-ship-cruise-in-croatia-october-2019

If you do take the trip and find that you just cannot keep up with all the walking tours, I suggest stopping at the local tourist office to ask its advice about what interesting part of town you could visit without too many physical obstacles.

You might also do some pre-trip research about nice scenery in the environs of your port city. I have been known to take a bus to a town an hour or two away just to see the scenery. The drivers were a bit puzzled about why I was (sometimes) on the next bus back to town, but so what? You could also ask the tourist office folks to recommend a bus trip somewhere that would allow you to see something other than the port town. I find those folks are pleased to have a traveler ask their opinion about what to do rather than just automatically going to the same place everyone else wants to see.

First, follow advice of your medical professional. Is it OK to travel or would it be BEST not to travel?

Second, recongize that the walking boot may at best slow you down because you will need to shorten your step and at worst may be an agility/trip hazard. Will you need crutches?

Third, the general advice for fractures is usually to "rest".

NECROPOST by n484588 reported to Webmaster for embedded link **(edited to add) and thus removed. I debated removing my post but decided to leave it so people would understand why the thread was bumped to the top.

OP was going to travel in summer and is doubtless back and with a healed foot.