@Mr.Clean Hello, again. I'll try and answer your questions with my experience with a complete release at the lesser trochanter. It has now been almost exactly 4 years since my release.
After conservative measures for my tendinitis due to acetabular prosthesis cup overhang, I had arrived at 2 options: revision of the cup or IP tendon release. I decided for the release as it was minimally invasive (all arthroscopic) and had little down time. In fact, I had my surgery on a Tuesday and my OS said I could go back to work on the following Monday if I wanted. I took 2 weeks as I had a very physical job and some good friends willing to fill in. My OS pointed out that he did a complete release for all of the THR patients that came to him as they found that it eliminated the possibility that the partial cut might not be enough or would heal shortened again and have to be repeated. He also allayed my fears in telling me that, once recovered, I shouldn't experience much, if any, muscle weakness. There are other muscles that fill in for the iliopsoas. That has proven to be true.
I only have a slight decrease in active range of motion in lifting (flexing) my leg past 90 degrees when standing. I have no issue with passive range of motion. None of this impacts my quality of life in any way. As far as I know, there have been no other physical impacts from the release. However, the tenotomy has positively impacted my quality of life by removing the daily pain I had, allowed me to get back to my favorite physical activities (no restrictions there except for what I already had from my THR-no jumping. marathon running, extreme sports.) It was so nice to be able to walk straight upright again and feel the complete relief that I had been anticipating with my THR. It took a few months for the strength to completely return to my leg but it had been down a long time from my arthritic hip and then the tendinitis. I still did not need to go to PT but that was always an option if I had decided to.
Someone from the forum was very helpful to me as I tried to decide which course (revision vs tenotomy) to take. Their observation: if the tenotomy doesn't work, you can always proceed with the revision. There are no guarantees here, as you well know. Every body reacts differently and recovers differently. You have to find an experienced specialist in arthroscopic hip procedures that you are comfortable with and then they have varying approaches as well. That being said, all things being equal, I would do it again without hesitation. I hope that was helpful. If you have any other questions or concerns that I can help you with, please don't hesitate to ask by tagging me. Blessings.