My hunch is that the nodule you see is a prominent osteophyte (also called a bone spur).
An osteophyte is a distinct mass of bone that forms in response to inflammation or injury. They can be small . . . or quite large (even the size of an egg).
Bone is a living organ and is constantly remodeling. After an injury to a bony area (like your knee injury several years ago), the ratio of bone building cells (called osteocytes) can outnumber the exceed the bone recycling/turnover cells (osteoblasts), resulting in a boney outgrowth or osteophyte. The skewed response of bone overgrowth can continue well past the initial injury leading to a prominent outpocketing of bone.
A large osteocyte can be painful and irritating. The lump of bone has nerve and blood supply. Hitting your osteophye on the edge of the table likely felt like stiriking your elbow’s “funny bone” (which really is the ulnar nerve). The pain is strong, sharp and immediate.
You may want to have your physician look at your knee osteophyte. Larger osteophytes can encapsulate tendons or ligaments and interfere with range of motion and be a source of inflammation and pain (which leads to the body to respond by trying to heal the area, sending more osteoblasts to the area . . . and the osteophyte grows larger).
Osteophytes that are troublesome can be shaved or filed down (think of a drummel nail file for dogs) or excised.
There is always some risk that the osteophyte can return as over-reactive healing response that promoted the original is osteophyte is not easily extinguished and attempts to remove the osteophyte heighten a similar healing response.
Osteophytes form due to an underlying inflammatory and healing response where the body’s goes into hyper-mode and the healing response is excessive.
I am sorry that you are dealing with yet another health Issue. I would have your physician or surgeon take a look at it, just to make sure that it is at lesser monitored and does not become larger or discomforting.
Post Edited ((Seashell)) : 2/12/2019 7:09:14 AM (GMT-7)