The femoral head is the round bit at the top of your thigh bone, your femur. It's the ball in the ball-and-socket joint of your hip.
In a total hip arthroplasty (a hip replacement, in other words), a titanium rod gets inserted a little ways down the center of the femur*. That part is meticulously measured and the rod is planted solidly. After the rod fits and the artificial socket up on the cup-shaped hip bone fits (that's the acetabulum, by the way), then the last bit in is secured to the top of the rod; this is the artificial dealio, made of titanium or ceramic or some other space-age material, that will become the de facto femoral head.
The femoral head is (on most adult people) slightly larger than a golf ball, smaller than a cue ball. Sitting there in a little metal tray, it can look awfully bewildered. Even, dare I say it, a little sad. A minute ago, it was an important body part, and now it's been replaced by some fancy-schmancy bionic thing. It's suddenly become medical waste. Hard to preserve your dignity in that situation, but the femoral head is nothing if not practical. It does retain some of its natural poise and beauty, despite being totally irrelevant at this point in the operation.
I thought it was sort of like the way a pitcher looks, when the manager walks out to the mound in the bottom of the fifth, with only one out and two of their guys on base, and says "nice work today, kid, but we need more juice out here right now. Hit the showers, willya?"
Except with more awe and respect. Not enough awe to make my brain seize up, though. Too much musing on the thin gossamer thread of every human's mortality, or the sacred yet profane work of we the blessed healers, can get in the way of people doing their jobs. And people doing their jobs is worthy of respect and awe, right there.
So, uh... yeah. I've had the chance to do some shadowing. Surgery is very, very cool. It's interesting to be aware of myself as someone barely scratching the surface. I know the names of most of the parts, and I understand much of what's going on. Yet outsider-style ideas and observations still bubble up. I'm hoping that I can hang on to some of that, along with all the actual knowledge and skill I'll be needing, when I'm standing in one of those other spots.
Total hip info (complete with gory photos) can be found here:
* Some marrow gets sucked out to make this work properly, and for some reason that part wigs me out more than all the rest of it -- including the part where the surgical team gets to be standing there in the first place, looking down into an open wound at the bones of a live person, like a bunch of guys eyeballing the half-disassembled transmission from a 1993 Ford Escort. And also, shaping the bones so they'll fit snugly with the implant. Shaping them with a saw. And a hammer and chisel. Ortho is cool as hell, and that's partly for the way it is not at all glamorous. It's clearly science and art, and one of the specialties that can make a person perspire from the physical effort of practicing it. As an Emergency kid, this is something I can respect.