hey that other johnny was not me, i never have met cattey so cannot answer any questions re cattey....
i am the johnny who did go to germany. dr muschaweck did two open surgeries for bilateral sports hernias.
i cannot help with all the technical mumbo jumbo re the pelvis. all i know is that i had massive, debilitating pains from this injury that radiated all over the pelvis. i got that book because i initially was being "treated" by a urologist. i always suspected that he was wrong and eventually bought the headache in the pelvis book since it discusses the condition the ur "diagnosed" me with. the book talks about the soft tissue in the pelvis and how it is suseptable to injury and thus musclular changes and imbalances. even more importantly, it discusses how the muscular problems can be treated, and when that happens, other dysfunctions and pains can resolve.
after reading that book, i took a new approach and eventually ended up getting surgery for the right thing.
as far as imbalances go- i hear that the sh is brought about by muscle imbalances; it can make one prone to the overloading of the wrong tissues which can cause AP to begin. i already had imbalances from long-standing knee problems. it took me 15 years to get my meniscus tear fixed since i was convinced that i was invincible and always ignored the pain since it didn't really interfere with my sports all that much. once it began to bother me, i noticed, but not carefully enough, how the pains had caused my knee to work differently (via compensatory patterns). and it works from there, spreading throughout.
i know some say the sh is caused by a collegen disorder that can be passed down genetically, but maybe those same collegen issues play a role in muscle imbalances...
either way, if you are going in for surgery, try to treat your tightened muscles (from pain/injury) and get them loose and relaxed before you go under, and of course, try to get the hip flexors strong if you have already seen lots of atrophy since the symptoms kicked in. it can only help you heal.
not too sure where to send you, i am no doctor, just going on my own experiences. i guess a good pt can help, as can a good do or a rolfer.
hope it helps.