Mystery Metal

I recently had an X-ray performed of my right knee. The reason was that I had a strange pain in my knee, but only when I was on all fours (table-top pose in yoga) and only if I rolled my knee in the right position.

It feels like a pin or tack poking into my bone when I am positioned properly. I asked the Doctor and he claimed (with much certitude and haste) that I have a torn meniscus.

I went for the X-ray and he called a few days later to tell me that he had, "Some weird news."

I have a 2.5 centimeter piece of metal in my knee.

I have no idea when this happened. I do not recall any such incident, and the candidates for such an inclusion are so large that I can't believe I would not have noticed them inserting themselves into my flesh.

The photo is a collection of likely suspects I gathered from around my house.

I am going to see the X-ray Monday (13 October) so the mystery may be solved then, but I might not know for sure until the thing is removed.

The objects are:

• shirt pin (round head)
• flattened staple from a staple gun (my personal favorite)
• shirt pin (flat head)
• finish nail

Enter your favorite in comments.