Could my SI joint be contributing to the coccyx pain?

Susy -

Posted 2011-03-27

I first began having coccyx pain in the winter of 2009 when I started training for a triathlon and was riding a stationary bike (regular stationary bike, not spinning bike) at the gym. I was riding twice per week, from about 30 to 60 minutes each time. I noticed coccyx pain, but it was not severe and was really more of an annoyance. The pain would usually not persist for long after I stopped riding. Once it was warm enough to ride outside, I began riding my own bike and did not have any pain. I went on to complete four sprint triathlons between June and September with no coccyx pain or other problems.

In October of 2009, I decided I would try spinning as an off season training option. About half way through my first class I felt the same coccyx pain I had experienced in the previous winter. I tried a few more classes with trying out different bikes and making sure I was fitted properly. However, by the last class, the coccyx pain was so terrible I almost could not complete the one hour class and decided spinning was not for me. The pain would persist somewhat after spinning classes, but not for more than a day or so. During this time I would also feel some mild coccyx pain when sitting for long periods of time (all day meetings, plane trips, etc), but nothing severe. At the end of December I purchased an indoor trainer for my road bike and used that all winter. I felt some coccyx pain on my first couple of rides on the trainer, but then it went away.

Fast forward to March one weekend I did a two-hour swimming clinic on Saturday, took my road bike out for the first outdoor ride of the season and went for a short easy hike on Sunday. Monday morning I had terrible coccyx pain that persisted through the day and made it nearly impossible to make it through the work day. The pain improved a little bit in the next couple of days, but was still quite severe for about 3 days. I then had some improvement and would feel fine during normal work days, but found that when I had to sit all day at a meeting, the pain would become almost unbearable. At this time I was also experiencing some lower back pain and decided to see my doctor.

I saw the nurse practitioner at my doctor's office who told me I likely had muscle strain in my back and a bruised tailbone and sent me for an x-ray to rule out a fracture. She recommended I see the chiropractor and if that didn't help, I should try physical therapy. The x-ray showed everything to be normal. I went to the chiropractor for about 2-3 months and felt some improvement in my back pain, but not much relief in my coccyx pain. During this time I was exercising 5-6 days per week, running, swimming, and biking. I would have pain in my coccyx when I had to sit for long periods of time without getting up, but would generally feel fine when just doing my normal workout routine and going to work. After the chiropractor did not really fix my problem, I tried physical therapy. I did physical therapy for about 6 weeks until it became apparent that my pain was definitely getting worse not better. I was now feeling pain every day and even after sitting for short periods of time. Getting through the work day was becoming quite a challenge. I cut back on my workout schedule and my primary care physician sent me for an MRI and recommended a spine center. By the beginning of August, I stopped exercising completely, with the exception of walking my dog.

The MRI results showed that I had a slightly bulging disc (at L4/L5) with a minor annular tear, and minor spondylosis, but the radiologist's report said there were no abnormalities with my coccyx. When I saw the spine specialist (mid-August), he told me that the MRI did show inflammation in the coccyx. He diagnosed me with coccydynia and said that he felt this was separate and unrelated from my lower back problems. He wanted to treat one problem at a time and thought it was best to treat the coccyx pain first as it was causing the most discomfort. He recommended two intercoccygeal steroid injections, two weeks apart. I had both of the injections and felt no relief after either of them. I then when back to the see the spine specialist and he said that the fact the injections were not effective probably meant I had a mechanical issue rather than just inflammation. He recommended I try acupuncture and if that was not successful, I should go see the only surgeon in Boston (Dr. Kirkham Wood at Mass General see Doctors and specialists in the USA, Massachusetts) who does coccygectomies. I had not been particularly impressed by the spine specialist, so I decided to not take his advice and go a different route.

Both my primary care physician and an acquaintance had recommended a comprehensive pain care center in the area, so I decided to give them a try. The doctor there also agreed that the back pain and coccyx pain were separate issues. He wanted to treat each with cortisone injections. Over the course of a few months, I had an epidural cortisone injection, a coccyx cortisone injection, multiple facet joint cortisone injections, and radiofrequency ablation (RFA) for the facet joints. I got some partial temporary relief from my back pain from the facet cortisone injections, but none of the other treatments, including the RFA, resulted in any improvement.

Completely frustrated with lack of progress, I decided to go see Dr. Wood, the coccygectomy surgeon, and made an appointment with him in early February. Dr. Wood said I fell into the category of people who have coccyx pain with no known cause. There is nothing in my x-rays or MRI to indicate a problem. He said there are lots of things you can try (many of which I have tried already), and if those are not successful, the surgery is another option. He told me it was a relatively simple surgery and successfully relieved pain in about 85 percent of cases. He did not give me a recommendation either way as to whether or not I should have the surgery, but left it up to me to decide what I wanted to do. I wasn't quite ready to decide on surgery yet without trying some more things.

The same week I saw Dr. Wood, I went for a follow-up appointment with my doctor at the pain care center. After further examination and questioning, he determined that my back pain was not caused by the facet joints as had been suspected, but by an issue with my sacroiliac joint. He recommended I have a diagnostic SI joint injection to confirm this diagnosis. I then went home and read all about SI joint dysfunction and it matched my symptoms exactly (my back pain was primarily on one side and radiating into the left side of my butt and my left hip). While I did not read anything that indicated SI joint problems could cause coccyx pain, I started to suspect the SI joint was causing both of my problems. I did have the SI diagnostic injection and was pain free for 6 hours, so my diagnosis was confirmed. At the same time he also gave me a diagnostic coccyx injection, and I also had no coccyx pain for several hours. However, the doctor wanted me to have RFA for the SI joint and I refused because I wanted something that would fix the problem rather than just killing the pain for a few months.

So, now here I am trying to figure out what to do next. I really feel that my SI joint may be contributing to the coccyx pain, but I don't know if this is actually possible. I am curious if there are other people out there who have coccyx pain and SI joint problems. I am headed back to my primary care physician this week and then to another spine specialist next week. After over a year of being in pain, I am certainly frustrated!

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