My semitendinosus muscle ruptured from the pelvis due to massive degeneration of the muscle in the following of the harvesting. The doctors say it is probably caused by either too aggressive harvesting or physical therapy after training. I described my physical therapy that I got and they agree that the training was way too harsh.
A good doctor should be able to diagnose muscle semitendinosus rupture by using his fingers and ultrasound sonography. If the muscle is ruptured from the pelvis then it should be little loose there when you stretch the muscle and also some atrophy should be visible at that place.
Later on my gracilis muscle ruptured, first from the pelvis and then from knee. I have had a total of 5 successful operations to correct the mistakes from the first surgery. My doctors are Uffe Jorgensen, Parkens Privathospital, Copenhagen , Denmark and Sakari Orava, Mehilainen, Turku, Finland.
I advise you to find a world class doctor who can help you.