Femur pain - bone excision - cancer biopsy negative

[exsoccerplayer]

I have developed an excruciating pain in my left femur - close to my left knee.  After getting 3 separate opinions, my 3 orthopedic surgeons have been at a loss in diagnosing my condition.  Two months ago, my latest surgeon performed a biopsy.   The biopsy revealed no cancer.  However, my MRIs continue to show a "shadow" near the left knee.  The "shadow" has not increased in size during the last 2 years.  However, the pain associated with this condition has increased to the upper part of my leg and hip.  I live in excruciating pain every day.  This same surgeon is suggesting an excision of the bone and a possible bone graft to replace the removed bone piece. After reading articles that describe several different bone diseases, and after finding similarities to my symptoms accross the board, I stand confused, frustrated and unable to get answers about my condition.

Do you have any suggestions for the possible disease/condition that I am experiencing?  
Do you see any problems with the removal of the bone piece and bone grafting process for my condition?  
Are there any potential problems that could be triggered through the removal of the bone piece that my surgeon should be considering - e.g., a bone fracture due to the weakening of the bone.  My doctor rules out any potential problems with the proposed surgery.  

Any information would be greatly appreciated.