Hi Sarah! I had a bit of this, when I began walking longer distances outside on the cement sidewalks. It is a real significant soreness, isn't it?
Shin splints are most likely due to increasing the workload as you are improving with your lovely new hip. I used ice packs after my walks to help ease the soreness and resulting inflammation.. then I skipped the walks for a week or maybe ten days? I really can't recall now. Then instead, I just worked on the recumbent bike.
I think I nipped it in the bud because it didn't return when I resumed my walks. Oh! I also did some stripping massage and in lieu of that, the rolling massager works pretty good, too. Like a rolling pin?
Hopefully if you can ice and ease up on the walking or like you said, avoid the harder surfaces, maybe that will do the trick for you, too.
On another note, what was your weather today? We hit 61 degrees here with brilliant sunshine.. so nice.
- that's me with a spring flower