Dissolvable Glass For Bone Repair 168
gpronger writes "Sticks and Stones May Break My Bones, but Glass Will Certainly Mend Them! The old schoolyard ditty may be changed to reflect developments using metallic glass that will dissolve in situ instead of the traditional stainless steel or titanium hardware, which require removal by surgery once the bone has healed. Physics World reports that researcher Jörg Löffler at ETH Zurich has created an alloy of 60% magnesium, 35% zinc, and 5% calcium, molded in the form of metallic glass. Through rapid cooling, the alloy forms a molecularly amorphous glass that slowly dissolves over time, supporting the injury long enough for healing, then slowly dissolving away."
Re:end to casts? (Score:3, Informative)
Only if you have a compound fracture, if you have a internal only fracture you will still need a cast.
Great news for outdoorsy types (Score:1, Informative)
The proper fusion of bone has always depended on the lateral strength of the bracing mechanism. While this does away with the need for painful pins and rods, it still requires the use of casts and other immobilizers. In the case of compound fractures, the bone splinters may be dislodged away from the point of fracture and still need surgery to remove.
Breaking a bone is never a pleasant experience, but rapid healing and non-invasive resetting should make recovery faster and less scarring. This particular advance in recovery medicine should help pave the way for technologies such as tricorder automatic healing and other non-touch healing techniques.
On the battlefield and anywhere where injury risk is very high and away from medical help, this type of at-the-scene treatment can help preserve not just bones and limbs, but lives too.
Kudos to the team for a great job!
Re:end to casts? (Score:5, Informative)
excessive soluble Magnesium in the body depletes calcium.
I'm sure they probably have thought about this. One could see this working both ways. Perhaps having magnesium in the replacment helps precipitate calcium in a useful place near the bone replacment. On the other hand soluble magnesium is know to rob bones of calcium, so a large source of soluble calcium especially concntrated near a weak bone might undermine it.
I have no idea what the right answer is here, but it does seem like something that need to be considered strongly.
Re:end to casts? (Score:4, Informative)
This technique is a lot more invasive than casting, and it's not injectable. They cut you open and place it just like the metal counterpart; the improvement is that you don't have to be cut open twice. So, better than bolting a metal rod down your leg, then removing it a couple months later, much worse than putting some plaster over your skin to keep you in place.
Re:Somehow... (Score:1, Informative)
Well, if it is, gpronger will be there to report on it. Hopefully while he's learning to fucking spell. 'Dissovable', 'hardwar'? Then there's the grammar FAIL of "hardwar[e], which require[there should be an S here] removal".
Re:reply (Score:1, Informative)
Minor misuse of /in situ/ (Score:5, Informative)
http://en.wikipedia.org/wiki/In_situ [wikipedia.org]
In biology, in situ means to examine the phenomenon exactly in place where it occurs (i.e. without moving it to some special medium). This usually means something intermediate between in vivo and in vitro. For example, examining a cell within a whole organ intact and under perfusion may be in situ investigation. This would not be in vivo as the donor is sacrificed before experimentation, but it would not be the same as working with the cell alone (a common scenario in in vitro experiments).
That is, the use of the phrase in situ implies that the person is dead. in situ literally means "as it is," and is more synonymous with untampered. In a literal sense, the bone could heal by itself in situ, but with an implant, tampering has already occurred, and the process is actually occurring in vivo, in a live organism. It's a minor quibble, but don't use Latin when you can just say "in place," "without further intervention," or "on its own." These would have been better choices, and clearer because they are plain English.
--
Toro
Spot the English major in this post. :^)
Re:Minor misuse of /in situ/ (Score:4, Informative)
In medicine, as distinct from biology, "in situ" has long been used to mean "where it already is inside the patient's body," whether "it" is something that occurred internally (e.g. a tumor) or something that was introduced from outside (e.g. orthopedic equipment.) "Dissolvable in situ" is a phrase used to describe dissolving internal sutures, which is probably the precedent here. Sometimes it refers to things that definitely don't dissolve; as a military medic, I often ran across the usage "bullet left in situ" in older patient records ... and that sure as hell constitutes "tampering," I think you'll agree. (This is much, much rarer in modern military medicine; most such records were those of retirees from the Korean War and WW2 eras, although it still does happen even today.) You may not like the usage, but it's standard enough now that calling it a "misuse" is a mistake.
Re:reply (Score:4, Informative)
First, it's not clear to me that "fluid" and "liquid" have different meanings.
Second, glass is actually a solid. Flowing glass is a persistent, but untrue, urban myth.
Re:I'm involved in something closely related. (Score:4, Informative)
Oh, for God's sake. The undeniable corruption in the relationship between the medical manufacturing industry (drugs and devices) and the medical industry proper (physicians and other health care providers) is absurd, no one's denying that. Yes, there are serious problems. Yes, enormous amounts of money go to people who neither create new medical technologies nor provide them to patients. Yes, a lot of doctors are easily influenced by hot pharmacy reps in low-cut blouses. Yes, this leads to all sorts of injustice.
But at the end of the day, advances in medical technology still help people. Next time you get sick or injured, if you want to restrict yourself to the level of medical care that was available in, say, 1850, out some abstract sense of justice ... go ahead. Nobody will stop you. But just during my nine years in patient care, from 1989 to 1998, I saw new devices and drugs that helped our patients get better come on the market at a dizzying pace. You'd better believe we were glad to have them, and our patients were too. Now I work on the research side of things, and while I know that there are a lot of parasites between "bench and bedside," in the long run I really don't care that much. What I care about is that something I do might, possibly, help patients recover who otherwise couldn't.
Also, I broke my leg rather badly four years ago, and I was lucky enough to get the absolute best orthopedic technology out there. I still have a chunk of titanium where bone ought to be, and it will still be there when they put me in the ground -- but before such technology was invented, I'd probably have been on crutches or at least a cane for the rest of my life. Guess which one I prefer? I don't know if my orthopod chose the brand of "nail" he did because he genuinely thought it was the best out there, or because some sweet young thing fluttered her eyelashes at him. What I do know is that it's very very good, substantially better than similar constructs I saw put into patients just a decade before my injury. And I'm not a member of "only the wealthiest" by any stretch of the imagination. Too bad dissolvable bone implants weren't on the market when it happened ... if future patients with the same type of injury are luckier, then this is a good thing.
Re:end to casts? (Score:4, Informative)
My point is that I'd hope parts aren't left in place if they interfere even minimally with movement.
As a side note, I enjoy handing the part to folks and asking them what they think it is. Typically, they'll turn it over and over, examining the screw and slide mechanism (this part went into the femur's ball) and puzzle over it for a while. The usual guess is "bicycle part". When I tell them what it is, while they're still handling it, the result is usually a study in ballistic trajectories. Even funnier was the little bit of gristle left lodged in the threads that, before it completely decayed away, would invariably invoke a look of horror when I pointed out it was a chunk of me.
Re:I'm involved in something closely related. (Score:3, Informative)
In situ? (Score:0, Informative)
If it is to be useful as a biomedical device then perhaps they should demonstrate that it is dissolved and resorbed in vivo.
Dissolvable in situ is ambiguous. We are able to create an in situ environment which will dissolve almost anything. eg. aqua regia.
in vivo is used to indicate within the biological system. in situ only indicates within the solution phase.
The most effective candidates are still those based upon hydroxyapatite (HA) and similar ceramic materials. HA is the natural matrix secreted by osteoblasts. Limitations are related to porosity and the ability of the osteoblasts to move through and remodel the biomedical implant as they would natural bone structure.