Sir,
We praise your journal and authors Gonnade et al., on the excellent recent publication titled, “Ganglion impar block in patients with
chronic coccydynia.”[1] Their study of patients with chronic coccydynia (coccyx pain) showed that ganglion
impar injections with local anesthetic block and corticosteroid significantly decreased
pain and disability scores even at the maximum length of study follow-up, which was
6-month postinjection.
The authors clearly described injecting the ganglion impar via the sacrococcygeal
junction. We would like to point out that other needle approaches can also be done,
depending on the patient’s anatomy. Specifically, interventional physicians should
be aware of alternative approaches via the first[2] or second[3] intracoccygeal joint (between coccygeal vertebral bodies one and two, or between
coccygeal vertebral bodies three and fourth, respectively). These approaches have
been referred to as being transcoccygeal, intracoccygeal, or coccygeal transdiscal.
These newer approaches have some potential advantages. First, since the sacrococcygeal
joint is fused in 51% of humans,[4] these newer approaches provide access through joints that are more likely to be
patent. Second, human cadaver studies have shown that the ganglion impar is usually
located at the upper coccyx, rather than at the sacrococcygeal joint.[5]
We noted that the authors excluded from treatment any patients who had imaging abnormalities
that would explain their tailbone pain. This surprised us since our experience is
that coccydynia patients often respond extremely well to these impar injections, regardless
of whether they do or do not have coccygeal imaging abnormalities. We would be very
interested in the authors’ thoughts on their exclusion criteria.
We hope our comments and the authors’ reply will provide even more insights on relieving
pain via these injections.
