"Gender-sensitive" knee implant designs
Apparently this is the next big thing in TKA (total knee arthroplasty). Back in 2006, both Stryker and Zimmer were touting their latest TKA designs; each claimed to be the first with a design created specifically with the female anatomy in mind.
The resulting debate in business and medical forums provided me with both amusement and annoyance. (Apparently I wasn't the only one rolling my eyes over the whole argument; back in March 2006, when the advertising campaigns for Zimmer's
Gender Solutions High-Flex Knee and Stryker's
Triathlon Knee System were running in high gear -- both designs were highlighted at the annual meeting of the American Academy of Orthopedic Surgeons -- Colin Barr of TheStreet.com included the marketing tug-of-war in his column,
"The Five Dumbest Things on Wall Street This Week.")
The idea of a gender-specific knee is an important step forward in the slowly evolving area of TKA. There are many well-documented differences between the male and female knee, including fat distribution, anatomical alignment, and bone structure; for example, the female femur and tibia are narrower and more elliptical in the sagittal plane. This idea makes a lot of sense to me.
There are skeptics. DePuy and Biomet, for example, have gone on record with the opinion that the anatomical differences between the male and female knee are not sufficient to warrant a gender-specific TKA design. However, I'm still working on digging up any out-and-out refutations of the pro-gender-specific arguments, of which there seem to be no particular shortage.
Further reading:
"The Female Knee: Anatomic Variations" (S. Conley et al.),
J. Am. Acad. Orthop. Surg., 2007.
"Total Knee Replacement for Women" [PDF, 3.6 MB] (J.N. Argenson),
European Musculoskeletal Review, 2006.
"Gender Specific Knee Replacement Implants" (J. Cluett),
About.com Orthopedics, 2007.
"Knee Replacements, Designed for Women" (A. Aubrey),
National Public Radio, 2007.
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Labels: engineering, science
Go Montana!
This kind of thing gives me hope that my constitutional rights are still relevant.
From the
Washington Post (full article >>):
"Montana officials are warning that if the Supreme Court rules in the D.C. gun ban case that the right to keep and bear arms protects only state-run militias like the National Guard, then the federal government will have breached Montana's statehood contract.
"Nobody is raising flags for the Republic of Montana, but nobody is kidding, either."If it comes to a Republic of Montana vs. a Big Brother kind of America, well, I know which side of the border I'll choose. I'd rather not leave my personal safety and that of my family in the hands of someone else, especially in light of the legal implication that
the police are not obligated to protect the citizenry. Also, I can't afford to hire a personal bodyguard.
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Labels: everyday, my future, ponderings
Car accident injuries
Before your next car accident, let's consider some of the myriad factors that affect how things may or may not go horribly wrong.
Occupants:- Front
>> Outboard only: driver and passenger- Rear
>> Outboard (2) and centerImpact/collision types:- Front
- Rear
- Side
- Oblique (bi-axial)
- Rollover
Vehicle safety features:- Seatbelts
>> Lap and shoulder belts
>> Belt auto-catch mechanism- Head restraint (headrest)
>> Height and distance away from head- Seat
>> Frame stiffness (resistance to bending and/or failure)
>> Seat stiffness (cushioning; resistance to loading by the occupant's torso)
>> Contouring (when the seat is loaded by the torso, how will the shape and relative stiffness of different sections of the seat affect the forces that build up on the torso?)- Airbags
>> Front, side, etc.Other factors:- Safety feature performance
- Internal structural failure
>> Displacement of vehicle components (e.g., if the door panel fails, you might end up with a piece of sheet metal in your ribcage)- External structural failure
>> Penetration of extravehicular objects into interior space (e.g. tree branches, signposts, meteors)- Occupant orientation at moment of impact
>> Is the torso twisted? Are the legs crossed? Etc.- Occupant's voluntary reactions to impact
>> E.g. bracingSome possible injuries and causes:- Steering column impact injuries
>> Usually seen only in frontal impacts; unique to driver position- Upper extremity injuries
>> Usually due to occupant bracing- Lower extremity injuries
>> Especially prevalent in frontal impacts; usually due to compressive loading- Whiplash-related injuries (neck)
- Head injuries
>> Especially prevalent in side impacts; can occur in frontal impacts due to poor shoulder belt performance- Torso injuries (thoracic, abdominal, pelvic)
>> Especially dependent on belt and seat performance- Injuries due to excessive loading of shoulder and/or lap belts
Now, doesn't that just make you want to go out and get into a high-speed rollover crash?
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Labels: engineering, imagine yourself here, travel
Sunrise over the Nevada desert
Once upon a winter morning, in the middle of nowhere in Nevada, I come to realize that the desert can be startlingly beautiful in its own way.
There is a hint of the pink-tinged, gold-warmed edge of dawn in the sharp, cool, dry brand-new-morning air. Dusty white frost powders the scrub brush, clinging low to the packed, sandy earth; sparse and brown-green, sagey, yellowed, the brush has a marathoner's wiry robustness, scrappy and thin like the deep, hidden water that the desert so jealously hoards. Thin, delicate sprites of clouds hang wispily around the mountaintops, the kind that burn away before the dry warmth of day. The sun works up slowly, hardly enough for warmth but enough to paint the brown, gullied mountains in a sweet, sugary, candied-fruit shade of orange-pink. It glimmers, shimmers, little baby heatwaves illusioning through the raspy dry air. Thin ice barely covers the green creek that winds in that corrosive, sinewy, side-twisting way through the painstakingly eroded gully in the flat spread of land ahead of the foothills. A low, single-wire fence gives substance to some hypothetical line through the desert; the fence is no taller than the scrubs, just man's attempt to toe a line in the shifting sands, no good hindrance to anything save a few plodding cattle and the uprooted vagrant tumbleweeds.
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Labels: imagine yourself here, ponderings, travel
The Great Mouse Jihad
My mother has declared holy war on the mice in our garage. I think it really became an issue when she discovered droppings on the shelf where she keeps her special gluten-free beer. The beer was fine after she washed the bottles a few times, but since then she's been a little crazy about it. I think she's taking it personally. Every time I see her, she says "I REALLY HATE THESE MICE!!!" and I'm at the point where my stock response is, "Yes, Mom, we know, thank you."
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Labels: everyday
Appalachian mornings
A typical early morning in the Appalachian Mountains has its own slow, distinct charm. A wide, still river slides placidly along beneath its shroud of mist; vaporous fingers trail languidly through the reeds along the water's edge, silent over the marshy ground, settling stealthily into the hollows -- lying in wait, perhaps, or merely in molasses-thick lethargy. Thin white mist floats over a dirt lane, fills the fresh-plowed furrows in the quiet fields, hangs like smoke under the trees, swirling in the low spots between the worn hills like an old banjo tune. The morning light is soft and diffuse in the solid humidity pooling near the ground, blanketing but not quite touching, hovering shadow-like, light and airy, between gravity and evanescence, smoking down out of the slowly warming air.
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Labels: imagine yourself here, ponderings, travel
I went to Salt Lake City and all I got was...
- Dry, irritated eyes and nasal membranes (really, their air quality isn't great)
- Bigger sleep deficit (Discovery Channel in the hotel, and not sleeping in my own bed)
- Up-front, standing-room-only view of Chris Sharma's awesome whipper off the top crux move of the USA Climbing men's national final route
- Bad case of nerves from seeing a bunch of tractor-trailers and RVs blown sideways off of I-80 by strong cross-winds in Wyoming
- A new perspective on pantry management
It's really the last item that I'm here to talk about. When we were in town in late January, the local supermarket chain Macey's was having their annual "Family Preparedness Sale." They were advertising great sale prices on gallon-deep cans, five-gallon buckets, and ten-pound (and larger) sacks of freeze-dried blueberries, dried beans, rolled oats, cracked wheat berries, instant milk powder, powdered eggs, and myriad other items, pretty much all you could hope for.
I don't have anything against Mormons personally; I'm not going to tell anyone what they should or shouldn't believe. However, there are two things I really admire about the whole Mormon culture: this preparedness thing (if the apocalypse ever comes, the world will be rebuilt afterward by Mormons, and by fortified back-country mountain folk and the paranoid freaks who have fully-stocked fallout shelters in their back yards), and their work ethic. There's a lot to be said for a serious work ethic, too.
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Labels: everyday, food, philosophy, ponderings, travel
