I was recently kicked with the heal of a skate blade......?

Question

I was recently kicked with the heal of a skate blade on the back of my thigh, a little above my knee. The ER doctor that stitched me up said that the blade hit a small artery and that it was a very deep cut but he just closed the skin with 8-10 stitches but I went to see my family doctor he said that I should of had stitches to close the muscle that was cut too. I am a figure skater so my legs are very muscular and have very little fat on them. Now that its healed I can feel a hole under the skin in the back of my thigh when I put my hand over it, what could that be caused by?

Answer 1

that little depression is where the muscle was not sewn back together and so healed apart. Your doctor was right, if the wound was that deep, you should have had a small surgery to repair the muscle as well as stitches to close the skin.

Answer 2

under my skin
A few weeks ago I went on a weekend bike ride along the Mount Vernon trail here in DC, braving the throngs of roller bladers, speed walkers, joggers, other bicyclists, and baby strollers. I should have just stayed home. The trail was even more crowded than usual, plus some bureaucratic meddler had put up metal crowd control barriers along the edges of the trail. Those barriers proved my undoing: I swerved to the side to avoid running down a jogger who looked like he was about to pass out from fatigue, and ran headlong into one. Failing to unclip from my pedals in time, I toppled over, skinning my knee.

A skinned knee is hardly a life-threatening injury, so I washed off the blood and bits of gravel with water and went on my merry way. When I got home, however, and did a more thorough cleaning, I discovered the wound was quite a bit deeper than I'd realized. Hydrogen peroxide and Neosporin were in order, along with a kneecap-sized adhesive bandage. (Jen-Luc Piquant recommended a honey and sugar paste, which supposedly has natural antimicrobial properties and reduces the chances of permanent scarring. Scientists aren't sure how the paste does the latter, but they suspect it curtails excess collagen production. Whatever. I'll stick with my tried and true Neosporin.) It was teetering on the border of the "cavity wound" category, in which a chunk of tissue is scraped away, leaving a cavity of some sort (mine barely qualified, but still...).

Be grateful I don't own a digital camera, otherwise you would have been treated to a series of photos detailing how this grotesque wound proceeded through the various healing stages. (What a great idea; I've got to break down and buy a digital camera so I'm prepared to document the next festering open wound I develop.) Those stages are very well documented, it turns out. Skin cells attach to a net-like mesh of proteins (an extracellular matrix) to orient themselves, a construction that some people have likened to eggs sitting in an egg carton. For cavity wounds, the body "fills in" the hole from bottom to top by building new tissue. I can verify that healing wounds appear bright red during this stage, as connective tissue cells multiply and form collagen, which in turn forms little red fleshy masses called granulation tissue, and this continues until the entire cavity is filled up and all that remains is a bit of scar tissue.


My biggest concern in the days immediately following my encounter with the metal barrier was staving off infection -- because don't you just hate the resulting pus-like seepage when that happens? I sure do. Fortunately, in addition to old standbys like Neosporin, you can now buy Band-Aids with antibiotics built into the protective gauze -- I have a box of them in a variety of bright fluorescent shades -- and last year researchers at the University of Florida took the concept one step further with the development of a new type of wound dressing to stem the spread of antibiotic-resistant bacteria in hospitals. (Sobering statistic: Nearly two million Americans per year contract a staph infection while hospitalized, and of those, several thousand die.) The University of Florida wound dressing features a microbial coating that can be chemically bonded not just to gauze bandages, but also to socks, hospital bedding and gowns. The anti-fungal coating makes the material super-absorbent so that it pulls excess moisture away from the healing wound, killing the most common and harmful bacteria in the process.

Getting rid of excess moisture is important not just to reduce infection; at some point the wound scabs over for protection to help expedite the healing process. I did what Mom always advised during my tomboy childhood: exposed the wound to air after a bit to let the telltale scab form. The problem is that it was right below the kneecap, a major joint, so every time I walked, or bent the knee in any way, the scabby covering would crack. Picking at scabs always makes it worse. That's because removing the scab also removes some of the newly regenerated tissues growing underneath, impeding the healing process. Scientists at Stanford University have been looking into why this might be the case by studying fruit fly larvae.

Michael Galko and Mark Krasnow stabbed the helpless larvae with needles to create deep puncture wounds, then studied how they healed. The usual blood clotting and spreading of new skin cells occurred, and they noticed the similarity in this process to the fruitfly's developmental stages. So they looked more closely at the genes involved, and discovered that one particular cell signaling pathway kicked in during peak healing -- specifically, it controlled the regeneration of the epidermis (but not the scab formation stage). They concluded that each stage of wound healing is controlled by distinct genetic pathways triggered whenever the body suffers such a wound. And the same probably holds true for mammals, not just Drosophila melanogaster.

Of course, one could argue that I prolonged the healing process by refusing to give up my usual gym workouts, which only exacerbated the cracks in the scabby covering. But this must be balanced against the recent finding that exercise helps speed the healing process by as much as 25%. And the faster a wound heals, the less likely it will become infected. This is based on a recent study at Ohio State University involving 28 healthy "older adults" (ages 55 to 77, with an average age of 61), each of whom agreed to receive a small puncture wound and let the researchers document how it healed. None of the participants had exercised regularly for at least three months prior to the study. Half of them were told to exercise three times a week for three months, while the other half maintained their sedentary ways.

The results: the skin wounds healed an average of 10 days faster in those who exercised compared to those who didn't. The biggest surprise was finding sharply boosted levels of cortisol in the exercisers, a hormone typically associated with stress. Yet exercise is widely believed to reduce stress -- which is why I make such frequently gym excursions. (To quote Robert DeNiro's anxiety-ridden mobster in Analyze This, "I got stress!") The working hypothesis for this result was that the stress of exercise enhances the regulation of cortisol, indicating one of those crucial biological pathways in the complex healing process.

These are all examples of the kinds of cutting-edge research that will be conducted at the four new Centers for Innovative Wound Healing being established by the National Institutes of Health, to be located at the La Jolla Institute for Molecular Medicine in San Diego, California; the University of Illinois in Chicago; Johns Hopkins School of Medicine; and Montana State University. It's a $13 million project intended to create more innovative therapies for things like burns, diabetic ulcers, gunshot wounds, and bedsores, not to mention cavity wounds and the odd skinned knee. And it's interdisciplinary in nature: the NIH seeks to bring together experts from fields as diverse as microbiology, dermatology, mathematics and engineering.

Math, you say? Well, bioinformatics and combinatoric methods, specifically. Andrew Baird is a molecular biologist who heads the new wound healing center at La Jolla. He plans to use these and other methods to evaluate simultaneously millions of individual molecules to determine which have the most potential for speeding up the usual healing process. Such molecules could be used to accelerate healing, deliver gene-based therapies to promote tissue repair, and perhaps even study how stem cells in bone marrow contribute to tissue regeneration. (Baird might be interested in the latest research by Brown University's Jay Tang and Jim Valles, who believe the physics of microtubules could hold an important piece of the puzzle when it comes to cell division and organism development.)

So mathematics can prove very useful in shedding light on the dynamics of wound healing, which is why it's been an active area of investigation since at least 1995, per this article unearthed from the New Scientist archives. More recently, Philip Maini is a professor at Oxford University in England who is applying mathematical modeling to study how cancer cells grow and woulds heal -- specifically, he's using the same equations used by engineers to model the stresses and strains in buildings to model human biological tissue. And equations describing diffusion -- "the process by which different substances mix through the random movements of their atoms and molecules" -- can also yield insights into chemical signaling in biological systems, including the chemical signals released by damaged tissue that turns on the generation of new cells to repair a wound.

In short, there's a lot we don't know yet about the underlying mechanisms beneath the skin that the body uses to heal itself. My knee has healed up nicely, for the most part, although there's still a pink patch where the wound used to be. Perhaps one day we can cover up such unsightly remnants as scars and pink patches with artificial skin. This is a very active area of research, particularly as it pertains to robots. For instance, a Japanese collaboration between cosmetics manufacturer Kao Corporation and Keio University have developed a new artificial skin that feels almost as soft as the real thing, despite being made of elastic silicone and urethane. (Item found via Rod van Meter's Live From Tokyo blog.) Jen-Luc Piquant somewhat snidely observes that this should bring joy to socially maladjusted perverts everywhere who dream of realistic sex with synthetic robots. But hey, she's virtual -- what does she know about the glories of the sense of touch? That sort of thing can make or break a robotic sexual encounter... um, or so we've heard.

Scientists at the University of Nebraska in Lincoln might end up giving a whole new meaning to the term "afterglow" with their electroluminescent robot skin -- essentially a thin film sensor that glows in response to applied pressure. That light can be recorded by a digital camera to produce a very high-resolution image. The layers of gold and semiconducting nanoparticles (cadmium sulphide) -- separated by insulating layers of polymer -- self-assemble out of solution, making it easier to "build" such sensors to conform to complex shapes, like human body parts or surgical instruments. The result: a thin film just 100 nanometers thick.

The Nebraska researchers came up with a fun way of illustrating the power of their new sensor: they pressed a shiny new penny against the device, producing a detailed image of Abraham Lincoln -- so detailed, one can see the wrinkles in Honest Abe's clothing and the letters "TY" in "LIBERTY." In addition to robot skin, or skin for prosthetic devices, such sensors could also be used in medical instruments. For instance, place such a sensor over an endoscope, and a surgeon would be able to remotely "feel", as well as "see", tissues inside the body. It's similar in concept to the pressure-sensitive, flexible electronic skin developed last year by scientists at the University of Tokyo, who embedded sensors in a thin plastic film that could be wrapped around objects, such as eggs.

All of which demonstrates that sometimes scientific truth can be stranger than fiction. Or not, at least when it comes to science fiction. Technovelgy.com reminds us that Roger Zelazny's classic sci-fi novel, This Immortal, features Rolem, a wrestling robot with pressure-sensitive skin. So perhaps this is more a case of science fiction once again inspiring real-world science.