We were on the Big Island for a week, while there I hiked to a place called the End of the World, which is out over a lot of uneven lava rock, where people jump into the water. We didn't jump this time, water was rough, and I wouldn't have been able to climb out, but anyway we also went to Volcanoes State park, and I hiked from the top of a crater all the way down, and about halfway across it. This was a huge accomplishment for me, we had not done this on a previous trip there in the summer when it was jut too hot for that kind of hike. We walked from our condo to the beach down the street each day, just everywhere we went involved some walking. It was a thrill for me to do all that, thinking about how much pain I would have been in if I had not had the surgery. I think your goal of hiking in 6 months is totally doable, and I think you will be surprised how much you will do even sooner, especially with the anterior. I had posterior and feel my recovery was pretty quick, overall.