From my experience in industry I have seen several product failures, and one of them was particularly interesting. The product was a spinal implant with unique fixation features. During development of the product, there was a lot of excitement because of the novelty of the device, and it was predicted to do very well once it launched. After launch and introduction to the market, it did not take off as expected, and instead sales remained quite flat. It was surprising, and we spent a lot of time trying to figure out why the product was not selling. We finally determined that the main cause for this was that the surgeons were having issues with the instrumentation that was used to insert the device. The lesson learned from this was that no matter how unique and innovative a device is, if the surgeon cannot insert it efficiently and easily it will not sell well.

The FDA recalled GE MRI in 2015.
Reason for Recall: Some MRI units may have been modified by service personnel or by equipment users to disable the Magnet Rundown Unit (MRU).
The MRU is one method used to shut off the magnetic field of the MRI in case of an emergency, such as when a metal (ferrous) object is brought into the magnetic field. In such an emergency situation, a delay in shut off can potentially result in life-threatening injuries. There were two reported injuries when hospital employees entered the MRI room carrying a metal container.
The use of affected product may cause serious adverse health consequences, including death.

I have worked on another project where it failed because of issues that it was having in the field. Our company acquired the product from another small start up company, and since the product was already 510k cleared and released to the market, my company decided to ramp up production and sell as much of this product, since it was being sold at a premium and was very profitable. That is when all kinds of issues started popping up in the field, with failures being reported. In the meantime we were working on integrating the product into our systems and procedures, to make sure the product conformed to our standards, and as all of these issues were popping up in the field we also were finding many gaps in the DHF and manufacturing processes. We then made the decision to recall the product and after finding out that we really could not fix the issues without a major redesign, we just canceled the project altogether. A couple lessens learned was that companies need to be very vigilant and thorough in their due diligence, and when acquiring a product, don't immediately ramp up production before fully understanding the production processes and before checking to make sure everything is up to good quality standards.

My office is a little unique in which we have a lot of products that we ultimately out-license to larger device companies. We develop the products and file patents on them and in some situations the market just isn't there. Most of our products fail because there is a competitor in the market and our product isn't differentiated enough to induce adoption. For example a manual surgical instrument is similar to an existing one or the procedure is now performed laparoscopically or robotically. In these cases, we ultimately abandon the patent.