It is my understanding that this muscle is cut during surgery?? and I assume repaired.
There are muscles cut during a hip replacement so that the surgeon can gain access to the hip joint in order to remove the arthritic portions of bone to be replaced with the metal implant. Any muscles cut would be repaired and should heal with no problems.
During recovery while doing a sidelying hip abduction I tore a muscle (there was little or no resistance opening my leg}. I've had groin, inner side leg and groin pain since then.
Surgeons will sometimes advise against doing side steps early in recovery and it's unfortunate that you received a muscle tear. Especially since you had pain after this event, you should have consulted your surgeon. Did that happen and, if so, what was his opinion for treatment of the tear?
I had a Magnetic artifact reduction MRI that showed "expected postsurgical tearing of the obductor internus and obductor externus".
The term "expected postsurgical tearing" confuses me a bit. It's not "expected" that muscles will tear during recovery from a hip replacement. Perhaps they mean that the tear was expected due to your complaints about the pain.....I'm just not sure of that part of the radiologist's report. Depending on the extent of a muscle tear, it may need some medical intervention, though. Your surgeon is the best person to determine this and discuss options with you.
Am I right the muscle is cut and repaired? And if so and torn can this be my problem?
Any muscles that are cut during surgery are repaired and expected to heal properly during recovery. Long term pain because of this process does not usually occur.
Unfortunately there are a variety of things that might impact post op pain a year or more out from surgery. It can be very difficult to pinpoint the issue. Your surgeon is the best person to start with to get answers to your questions. He will be able to tell you what muscles might have been cut and repaired. He should also be able to offer an opinion on the muscle tear that imaging shows you have. But there can also be impingement problems with the various soft tissues and the acetabular cup. Bursitis is sometimes a problem, as is tendonitis or bursitis.
I'll be interested to hear how your next meeting with your surgeon goes. I'm sorry I don't have any definitive answers for you, but hopefully my post can help you begin a good discussion with your surgeon.