Monday, October 3, 2011

New Medical Device = Guinea Pig Patient

     By now almost all of my readers have probably read about the horrific results that have developed and will  continue to develop in some patients whose artificial hip is the new one of metal-on-metal rather than the old one of metal-on-plastic.The old artificial hip used a metal rod with an attached metal ball to replace the upper half of the femur, and installed a plastic cup into the acetabulum, or that part of the pelvis with  which the femoral head fitted and subsequently pivoted, rotated and articulated , just as in the old hip joint. The new artificial hip used a metal cup instead of plastic so there was constant grinding of metal-on-metal.

     Unbeknownst to anyone, this constant grinding of metal on metal created thousands if not millions of tiny metal splinters and released them around the joint space. The white blood cells engulfed and tried to destroy them as if they were foreign invaders (which is why an unattended splinter in your finger turns red and the surrounding area gets tender). The subsequent release of inflammatory chemicals generated by the white blood cells apparently caused chronic pain and also damaged some of the leg muscles around the joint, necessitating the replacement of the new metal-on-metal joint with the older metal-on-plastic one.

     I mention this not to criticize the inventor of the new artificial joint, but to illustrate the dangers inherent in replacing a " tried-and-true" device with a new one that has theoretical advantages. There is no experimental way to mimic the effect of inserting a medical device into a human being for five minutes, let alone five years. In my opinion unless a medical device immediately provides a tangible benefit that no previous device did, you should let someone else be the guinea pig and have it inserted in them for the first six months to five years of the release of the new device. BTW, did you know that the salesman for the new orthopedic device often accompanies the surgeon into the OR to verbally instruct in  the insertion of the device? You certainly have the right to (a) ask the surgeon how many of these devices he/she has personally installed, and (b) ask that only doctors, nurses, etc. be allowed into the OR while they are operating on you, or that you be told who besides the surgeon will be present.

     The FDA clearance of a device does not imply verification of its "duty cycle" This is an engineering term. A light switch has a (tested) duty cycle of, say 10,000, meaning that it can be turned on and off at least 10,000 times before it fails to work., A light bulb has a defined duty cycle based on how often it is turned on and off, and for how long it is kept lit each time. A soldier's rifle has a tested duty cycle, as does your car's ignition and  your electric garage door opener. (For a wonderful movie  about the vibration duty cycle of the tail of an airplane, I heartily recommend "No Island in the Sky", based on the novel of the same name by Nevil Shute, and starring James Stewart as the airplane designer and co-starring Marlene Dietrich and Glynis Johns.) But the duty cycle of any device inserted into a human being is NEVER tested under true operating conditions. Thus we have had some  heart valves that shattered, or some that  clotted in an unacceptable way. We have had new materials inserted into human bodies that were subsequently rejected by the body and had to be removed. If any doctor wants to insert a new material into you (and to me "new" means being on the market for less than 5 years), I would think carefully before agreeing. The same would apply, for different reasons, if a new drug has been out for less than six months, unless no other drug does what it does, e.g. oral Dabigatgran. And remember also that you may be able to tolerate a brand-name drug, but be allergic to the products that are use to constitute the tablet that contains the generic drug.

     What this means is that any new product implanted in your body is a potential time bomb, similar to the cardiac (heart) permanent pacemaker wires that broke inside the body after months of use, or the use of Xrays to treat childhood acne which  greatly increased their risk of developing thyroid cancer, or the rush of men to treat their prostate cancer with external beam radiation rather than surgery in the belief that this treatment lessened their chance of becoming impotent which has been shown not to be the case. When it comes to surgery, newer is not necessarily better, and we should not confuse the French work "neuf" with the French word "nouveau".Remember that the purpose of all advertising, including the advertising of medical services and products, is an effort to convince you to buy or insist on using the advertiser's product, just as in the 1920's tapeworm eggs were advertised and sold to women as a guaranteed method of weight loss.

     Finally, remember that the government always has its own agenda, and you might not know what it is truly looking for. To mention some of the more egregious government-sanctioned medical "experiments" on unwitting human guinea pigs (and Wikipedia can give you further information on each indicent) we have had (1) The Tuskegee experiment where Negro men in the USA were infected with syphilis without  being told what was being done, and with treatment then being withheld so the doctors could study the "natural" course of the disease, (2) The infecting of Guatemalan natives with gonorrhea, again without telling them what was being done to them, or offering any treatment (3) the testing of the efficacy of Birth Control Pills on females in Puerto Rico who were told that they were getting a free pill to prevent pregnancy, but  50% of the women received sugar placebos instead without being told of the substitution. I won't even mention the escape of nerve gas from the U.S.Army Proving Ground in Dugway, Utah that killed over 6,000 sheep, or the CIA putting LSD into the drinks of unsuspecting drinkers at bars in the 60's to study the effects of LSD on unsuspecting users.

     And be very careful about announcing that the (government) agent is wearing no clothes. In 1947 or so, a noted atomic physicist, Lewis Branscomb, was appointed head of the National Bureau of Standards, In the course of his government-directed studies, he conclusively demonstrated that an advertised additive did not extend the useful life of a car battery. He was subsequently hounded and persecuted by the Senator from the state in which the additive was manufactured.



  1. An article on the front page of today's NY Times Business Section (Friday, Dec 23) quoted a study that reviewed hip and knee implants in Australia between 2003 and 2007. The study found no improvement, that 30% of the patients did worse than with the old implants, but the newly designed implants cost more, of course.

  2. In today's (Wednesday, Feb 15)NY Times one of the headlines on a front page story is: "Hip Implants U.S. Rejected (by our FDA)Sold Overseas".

  3. On the front page of today's (Wednesday, Feb. 22) NY Times, in the business section, that Johnson and Johnson had discussed the failure rate of their all-metal hip replacement among themselves.

  4. On the second business page (p.B2) of today's NY Times (Wednesday, Feb.29) was an announcement that Great Britain has advised all patients who received an all-metal hip replacement that they should be examined annually to look for any tissue damage that the artificial hip has caused.

  5. An article in the British journal Lancet (13 March, 2012) showed that metal-on-metal hips are more likely to fail within the first five years of implant than other artificial hips, and that women are at greater risk than are men.

  6. On January 17, 2013, the FDA issued a Safety Warning for orthopedists to discuss with their patients before implanting a metal-on-metal hip.

  7. The January 23, 2013 issue of the NY Times had a front page story that one maker of metal-on-metal artificial hips knew from their clinical studies and follow-ups that there was a 40% failure rate in 5 years, and some of these hips have been taken off the market. Once again it may be unwise to be the first patient in whom a new medical device is implanted.