I do not think he has found the right doctor. Pain is a sign of injury...he needs to keep pushing his way through the maze of Doctors until someone hears him. It is wrong not to do more tests. MRI, CT and even an angio if they cannot find it as he needs treatment ,as it could heal incorrectly and have problems all his life.It mght be a tendon but they still need to address it.
as far as he knows there was no injury
please dnt take offence to this but is your boyfriend a bit on the big side not fat but does he carry a little bit of wait. because that can cause really bad problems for your knees and elbows does he experiance any problems in pain with his elbows. i am on the heavy side and my knees are like that but my knee allso pops out of place and cracks alot. ive had many x-rays to see if there is another reason for this happanin and they cnt find any other answer i hope i have helped and not just insulted you if i have i send my apologe's (sorry for the spelling as well)
he is not large enough to put enough stress on his leg to cause the amount of pain he is in, also the pain is at a point that he no longer is able to exercise.
oh right. sorry i couldnt have been of more help then and i hope you find out what the source of the pain is soon.
Welcome to the MedHelp forum!
Pain in the front portion of the knee can be caused by bursitis (inflammation of the lining of the joint), arthritis, or injury to the patella cartilage (front portion of the knee). Try and consult a rheumatologist and also see if MRI of the knee joint was done. If not then a MRI should be done. Take care!