A neuroma is a benign tumor made up of nerve cells. Benign means it’s not cancerous and not dangerous. It can be, however, quite painful. The most common cause of this type of neuroma is direct injury to the nerve.
When the tendon was harvested from your knee, the nerve was most likely cut. This is a common problem with this operation. Knee pain prevents the patient from kneeling or moving around on the knees. Once it happens, there isn’t much that can be done. Prevention is now possible with an alternate method of operation. This uses the tendon from behind the knee instead of the front.