Implanted medical devices are one of the most profitable businesses of the U.S. healthcare industry. While many devices help extend and improve quality of life, a great many others may not be necessary. In some cases devices such as stents, screws, and artificial joints do not work well or are not any better than a cheaper procedure; in others, the risks may not be worth the benefits. All of the devices place a large cost-burden on U.S. medical spending, whether entirely effective or not.

• Read: The Eleven Most Implanted Medical Devices In America

On a yearly basis, medical device companies across the world bring in over $200 billion in revenue. In the U.S. alone, these companies take in over $85 billion a year. A large portion of that is for devices that are implanted in the human body.

On the whole, there is little concentrated information on the industry. Data on which company makes what device; sales figures of each individual implants per medical device companies; or the number of procedures done for each implant each year are not always readily available. More troubling, there is little information gathered in any one place about the potential dangers and flaws of these devices, or the complications that occur due to their implantation procedure.

24/7 Wall St. has examined National Health Survey data, multiple professional physician services, peer-reviewed journals, and SEC filings to complete a list of the most frequently implanted medical devices today. While many of these are life saving, controversy swirls around several others. In some cases, we found exact total costs from self-reporting by physician sub-specialties. In others, we estimated costs based on medicare outlays, industry reports, and academic publications.

Many of the devices implanted are medically necessary and do their jobs extending lives and improving quality of life, the 24/7 Wall St. research shows. Some products, such as artificial knees may even be underutilized. Others, like implantable cardio-defibrillators, may be over-utilized. What is certain in most of the cases we reviewed is that the effectiveness of these devices is not as well researched or understood as their widespread use may imply.

These are 24/7 Wall St.’s Eleven Most Implanted Medical Devices In America.