November/December 2007
Volume 3, Issue 6

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Coccydynia: A Painful Tale

An Original Contribution by Stacey Lendener, M.D.

Coccydynia, pain associated with the tailbone, is a relatively common ailment that is encountered frequently in pain management. The word coccyx is derived from the greek cuckoo, reflecting the likeness of the bone’s shape to that of the cuckoo’s beak. The condition, first described in 1588, has remained poorly understood and thereby often is untreated. Traditionally, patients suffering from coccydynia were often been disregarded and their complaints dismissed as psychological in nature.

Coccydynia is more common in women and while trauma following childbirth or a fall and tumor can cause coccydynia, most often the pain is idiopathic. While in most cases symptoms resolve within weeks to months, cases of intractable coccyx pain do occur, and pose a formidable challenge even to seasoned practitioners. In 80% of humans the coccyx is comprised of 4 fused vertebrae. There is variation in the number of segments as well as their degree of fusion between those segments, affecting the segmental mobility. The shape, angulation, and mobility of the coccyx have all been suggested as contributing to predilection to coccydynia. The coccyx serves as an attachment site for numerous muscles and ligaments, including the levator ani muscle group that supports the pelvic floor and assists in continence. The sacrococcygeal ligaments, and fibers from the sacrospinous and sacrotuberous ligaments attach to the coccyx as well, stabilizing the inferior spine and pelvis. While in the seated position, the coccyx is the midline component of a weight bearing tripod formed with the bilateral ischial tuberosities; thus, patients who suffer with coccydynia often lean forward or shift their weight to one side or the other when sitting to relieve the pain. The pain is typically felt between the gluteal muscles at the gluteal cleft above the anus. The pain of coccydynia is typically sharp and can radiate to the rest of the pelvic floor lasting from a few minutes to constant. A common complaint is tailbone pain that worsens with prolonged sitting or with rising from seated position.

Some cases are caused by direct trauma due to fall or injury during child birth, but most cases are idiopathic. One hypothesis, most described by Maigne, is based upon hyper-mobility at the sacrococcygeal segment. Dynamic radiographs can be performed in the seated and standing position to measure the angulation and degree of mobility. MRI, CT scan, or bone scan occasionally are ordered if there is any suspicion of more significant pathology such as malignancy.

Beginning treatment in the early stages helps reduce the likelihood of developing chronic coccygeal pain. There are several effective treatments available ranging in degree of intervention from a donut seat cushion to complete coccygectomy. For most mild cases which are often self-limited anti-inflammatory and over-the-counter pain medications, a wedge or doughnut seat cushion will suffice. Physical therapy including pelvic floor stabilization and coccygeal mobilization can often bring relief. Occasionally treatment of trigger points in the pelvic floor musculature are required. If symptoms persist and are severe interventional pain procedures may be of benefit. Caudal epidural injections with fluoroscopic guidance can often bring relief of coccygeal pain, particularly if any underlying radicular pathology exists. Additionally, neural blockade of the ganglion impar can significantly reduce or eliminate coccygeal pain. The procedure involves placing a needle under flouroscopic guidance through the sacrococcygeal ligament to deliver anesthetic to the impar ganglion anterior to the sacrum. Additionally, spinal cord stimulation may be helpful in severe, refractory cases of coccydynia. Coccygectomy has been used as a treatment of last resort, however no convincing evidence supports these procedures and complications have been reported.

Figure 2 illustrates the Lateral view of the pelvis and coccyx. The bracket shows the area of focus for radiographs that would provide a coned-down view of mainly the coccyx and distal sacrum. A more common lateral view would often also include larger bony structures, such as the lumbar spine and femur, all of which would make it difficult to optimize visualization of the small bones of the coccyx. In patients with coccyx pain, these coned-down, lateral views of the coccyx can provide important diagnostic information. Coned-down images obtained in the weight-bearing (seated) position can be compared with those obtained in a non-weight -bearing position (e.g., side lying), thus allowing assessment for dynamic instability (e.g., dislocations that occur only while seated).§