Implant Identification, A Needed Service

by James D. Hundley, MD


Total Knee Prosthesis,
Model and Manufacturer Unidentified

From time to time I have been confronted with an implant that I did not recognize and could not find out what it was. Who hasn’t seen or heard of a bent femoral rod from trauma? If you haven’t, you likely will. Another example was an intramedullary rod that had been in a femur for thirty years and had to be removed for a total knee replacement. There are knee and hip prostheses that had been implanted at “Elsewhere General” and needed to be revised.
When I looked for a source that listed implants, I couldn’t find it. That’s when was conceived. That has proved to be immensely popular and useful for finding sources of implants, but we needed more. You still had to know what you were looking for. The next stage of evolution was “Implant Identification”.
As orthopaedic surgeons and operating room nurses know only too well, removing implants can be tricky and is not as easy to do as the x-ray might “suggest”. Various rods have a variety of cap screws, removal threads, locking screws, etc. You must have compatible instruments. If you are revising a total joint replacement implant and don’t need to revise all components, it is essential to know the brand and model of the device. Thus, you can match compatible components and preserve that which seems better left in place than removed.
Naturally it’s better to get the operative notes from the original surgery, but too often they don’t describe the implants. The best source I’ve seen are the implant package labels that the OR nurse affixes to the operating room record, but they are not always available.
At the suggestion of an orthopaedic professor, we started collecting x-ray images of identified implants on a few years ago. Since this is something that will always be evolving and since we wish to provide free access to our colleagues all over the world, we chose the Internet as our platform. Our library of implants has grown but needs to grow more. To do so, we need your help. Why would you wish to go to the trouble?
1. As time passes, more and more devices will be implanted in younger patients. Many will live into old age. When the time comes to do something, records may be unavailable, the surgeon may no longer be in practice, the surgeons and product representatives who may recognize these implants will be gone, and so on. By going to our library of X-Rays, you at least have a chance of figuring it out.
2. Please remember that what is familiar to you in your time and locale may very well be unfamiliar to someone else in another place or time. Thus, we are not just looking for what you consider uncommon, but we’re looking for what you implant in your everyday practice.
3. Some implant companies have their own library of images of their implants, but they are predominantly specific to their implants and not necessarily available to us.
4. Privacy rules are making it harder to obtain records, even with signed releases from our patients. I know about that from experience.
5. Our population is aging and people move around. There will be more and more people with implants. A growing number will need second surgeries in places different from the original hospitals.
6. The educational benefit has been an unanticipated bonus. Nursing and technical schools use our images to train their students. Medical schools in some countries do the same. At least one large orthopaedic manufacturer uses our service to train their new representatives. Furthermore, surgeons can send their patients to the site to see what various implants look like, including some cases that they have performed.
7. Those who give presentations need illustrations for their slides. You/they can copy the images from “Implant Identification” for those presentations.
8. We will make a donation to the Orthopaedic Research and Education Foundation in honor of those who submit images of x-rays.
9. You can post “unknowns” yourself in hope that our colleagues will help you identify your inherited, troublesome implants.

So, how does one submit an x-ray? Go to and “roll over” “Implant Identification” on navigation bar near the top of the page. Click on “Submit an X-Ray”. The rest should be easy. If you have problems, please contact us at
Oh, how about patient privacy? When you submit images just crop out information that may identify the patient.
Thanks for your help. We’re all in this together for the benefit of our patients.

Dr. Hundley is a retired orthopaedic surgeon with forty years of experience. He is the president and a founder of