Interview with Dr. Patrick Foye on tailbone pain

By Michelle Dela Rosa, PT

I had the privilege of speaking with Dr. Patrick Foye, a longtime expert in the treatment of coccyx--or tailbone--pain. Below is a transcript of our interview highlights on the enigma of tailbone pain.

---

Dela Rosa: I'm here with Dr. Patrick Foye, who is the Medical Director and Founder of the Tailbone Pain Center at Rutgers New Jersey Medical School and Professor of Physical Medicine and Rehabilitation. Thank you so much for speaking with me today. In your experience, why has tailbone pain been challenging to diagnose and manage outside of the Tailbone Pain Center?​

Foye: I think that the biggest problem is that the vast majority of physicians unfortunately have a huge blind spot when it comes to understanding coccyx [tailbone] pain. We learned almost nothing about the coccyx in medical school. This leads to four main problems.

1. First, unfortunately many patients suffer for months and years before anyone even figures out that the pain is coming from the coccyx.
2. Secondly, most doctors do not really try to figure out what is causing the tailbone pain. Instead they label this as "coccydynia"; which literally just means coccyx pain, which is a symptom. We need to find the cause of that symptom.
3. Thirdly, the doctors often do not take the pain seriously, telling the patient that it is “just“ your tailbone. They minimize the symptoms and are sometimes even dismissive, in a way they would not treat patients with pain at other body regions.
4. Fourthly, doctors will incorrectly tell patients that there is nothing that can be done to treat tailbone pain, or that the only treatment is surgically amputating the coccyx (coccygectomy). Those ideas are completely outdated and completely wrong.

Dela Rosa: Your book Tailbone Pain Relief Now! describes the many reasons why people end up with tailbone pain. Are there 1 or 2 causes of tailbone pain that are more common than others?

Foye: Great question! By far the most common cause coccyx pain is when there is an unstable joint between the bones of the coccyx. Many medical textbooks and websites incorrectly state that the coccyx is a single fused bone. But that is rarely true. In the vast majority of humans, there are 3 to 5 individual coccygeal bones, with variability in whether there is fusion between any of those bones. Most people have at least a few coccygeal joints. And most people with coccyx pain have joint hypermobility (excessive movement) as the source of their pain.

The second most common cause of coccyx pain is a "bone spur"; extending from the lowest tip of the coccyx. When this happens at the bottom of the coccyx, there is thickening of the bone that projects backwards, often coming to a sharp focal point. It’s almost like a tiny icicle made of bone. This bone spur pinches the skin between the spur and the chair where the patient sits, and especially when they sit leaning partly backwards.

Dela Rosa: Thank you for clarifying the common causes of tailbone pain. In your book, you detail some of the seat cushions and medications that may help. People ask about injections for pain. As a pain management doctor, would injections be helpful for these causes and if so, could you describe how and what kind?

Foye: Sure it's a great question. Medications by mouth have a couple of big problems with them, which is why a lot of times medication given focally by a small local injection could be superior. 

When medications are given by mouth, number one they go through multiple places throughout the body. If you're taking medication by mouth, they can cause side effects in the stomach, the intestines, the liver, and the kidneys, so the side effects can be quite limiting. 

The second problem with medications by mouth is that because the medicine travels throughout the entire body, it gets diluted out. So only a minuscule amount of the medication actually makes it to the tailbone where the patient needs it the most. Many of these patients do respond to medication given locally at the site. Typically, that's done under fluoroscopic guidance. Fluoroscopy is like x-ray up on a computer screen, and using fluoroscopy we can target a specific location at the tailbone. I'm generally opposed to blind injections, which is where injections are done without any image guidance because 1) you can't guarantee where the medication is going to go and whether it's actually given at a place where it's going to be helpful, and 2) you also can get into problems if it's given in the wrong place - it can cause side effects. 

So back to your question, which was about the diagnoses like hypermobility or a bone spur... Absolutely those can respond very, very well to placing medication locally at the spot under image guidance. Often that's a combination of steroid which helps to fight inflammation, and also local anesthetic which can be given as a nerve block and can be very helpful when there's hyperactivity or hyperirritability of the nerves.

Dela Rosa: How is the x-ray your center performs different than how many other facilities perform the test?

Foye: Here at the Coccyx Pain Center, the biggest difference is that we take coccyx x-rays while the patient is sitting down, since that is when tailbone pain hurts the most. I have trained the radiology technicians here regarding how to properly perform this technique, which was first developed in France. Very few places in the United States have ever heard of this approach and even fewer are experienced at doing these x-rays properly. We have evaluated and treated thousands of patients with tailbone pain, many of whom fly in from around the country and internationally. And it is extremely common that patients had previous imaging studies that were read as being normal. But then they come here and our seated x-rays show that when the person sits down and leans backwards (putting their body weight onto the coccyx) they often have very dramatic dislocations or other abnormalities that would be completely undetected if the x-rays had not been done while the patient was sitting. It is a huge relief for patients to finally have an answer as to what is causing their pain. Then, when we have identified a specific cause for their pain, we can provide treatments for that specific cause, which is much more likely to be helpful than generic treatments done blindly without a diagnosis.​

Dela Rosa: Great thank you! Another follow-up question to the x-rays...I was amazed to learn that many x-rays that are meant to look at the tailbone don't even include it! So, what is your advice to a person with tailbone pain to ensure that the x-ray that they're getting (if they're not getting it with you), is accurately capturing the image of the tailbone? ​

​Foye: A lot of this goes back to and starts with the general lack of awareness that physicians, radiologists and radiology technicians have about tailbone pain. Frequently, they lump it all in with low back pain. Lumbosacral pain is thousands of times more common than tailbone pain. A lot of the automatic checkoff boxes that people have on their radiology x-ray or MRI forms will have a box to check off for lumbar spine or lumbosacral spine, but they will not have a box to check off for the coccyx or tailbone just because it is thousands of times less common. So what happens is that the primary care doctor, or the orthopedic surgeon, or the pain management doctor, will check off the box and order lumbar or lumbosacral x-rays or MRI, and then that doesn't even include the tailbone at all. 

The next problem then is that the study gets done and the patient is told that there's nothing wrong, and that there's no explanation for their pain when really the images did not even include the symptomatic area, or worse yet, it shows an incidental finding of the lumbar spine that may not be causing any symptoms at all. But now they start down the treatment path of epidural injections, and even spine surgery and other things for a part of the body that wasn't even causing the problem. So basically back to your question about what the patient can do: 1) look at the orders, look at the x-ray or MRI orders, make sure that the ordering physician has specifically explicitly requested imaging of the coccyx, and 2) when you go into the radiology center, make a point of talking to the radiology technician and being crystal clear with them that this is not your lumbar spine, that this is not up in the small of your back at the belt line, that the pain is specifically down at the coccyx, and make sure that the radiology technician is going to include that part of the anatomy within the study. It really does require a certain amount of self-advocacy by the patient unfortunately to fight this uphill battle against the ignorance that's out there.

Dela Rosa: I'm just curious, have people come to you from outside of the US? Or are you mostly seeing people domestically?

Foye: Most of my patients travel in from out-of-state and about a third of my patients fly in. It's maybe 5% or less that are international. Within the last six to 12 months, I've had patients from Japan, Sweden, Africa, the UK, New Zealand, and I think two from Australia. Which really just gets back to that there's this unmet need out there and patients who are not able to find local clinicians who will either take them seriously or that know the appropriate testing and treatments to provide.

Dela Rosa:  How do you work with pelvic floor physical therapists in the treatment of tailbone pain?​

​Foye: As a physician specializing in Physical Medicine and Rehabilitation (PM&R), I'm a strong advocate for the role of physical therapists in treating patients who are suffering from painful musculoskeletal conditions. Historically, a big problem was that very few physical therapists were comfortable or experienced in treating pelvic floor problems. Fortunately, that has been improving in recent years.

The pelvic floor is often described as being like a muscular sling, or hammock, which supports and holds up the pelvic organs. The back end of that sling has attachments to the coccyx. Pelvic floor physical therapists and I often collaborate on figuring out the "chicken and the egg" phenomenon. By that I mean that we assess whether a patient is having tailbone pain due to pulling and tugging onto the tailbone caused by tightness and spasms of the muscles that attach to the coccyx. Or, sometimes it could be just the reverse: a painful condition at the coccyx itself might be causing reactive muscle spasm and guarding of the pelvic floor. If evaluation and treatment at one location is not providing adequate relief, then it often makes sense to collaborate and to consult each other, to help the patients find the answers and relief that they deserve.​