The tailbone (coccyx) is the last part of the spinal column. It is a remnant of a rudimentary tail-like protrusion that is present in a fetus at about the 4th week of development. The coccyx is made up of between 4 to 5 underdeveloped vertebral bones. The uppermost coccygeal vertebra fuses with the sacrum while the lower 3 to 4 bones fuse together. The joint between the sacrum and coccyx is almost immobile joint (synchondrosis). The coccyx, like the lower half of the sacrum, bears no weight when standing. Instead weight is transferred to it while sitting, particularly when sitting backwards. Pain emanating from this bone or the sacrococcygeal joint is known as coccydynia.
Causes of Coccydynia
Tailbone Pain in Women
Tailbone pain (coccydynia) is not an uncommon condition. It is sometimes just passed off as low back pain or buttock pain or in women as menstrual pain. Coccydynia is more common in women since the female pelvis is wider and the coccyx is therefore exposed. Very thin women are at even greater risk since the fat padding of the buttock is minimal and does not cushion the coccyx when sitting. These days coccydynia has become more common as the modern lifestyle has become largely sedentary and involves sitting for long periods of time.
Tailbone Pain During and After Pregnancy
During pregnancy, the high levels of hormones causes the sacrococcygeal joint to become more flexible. This is necessary for childbirth. However, the coccyx serves as an important site for the attachment of certain ligaments and muscles via tendons. With increased flexibility there may be abnormal movement of the coccyx thereby increasing the tension on these tendons and ligaments. With prolonged labor, the coccyx may also run the risk of dislocation despite its increased flexbility. These are important possible causes of tailbone pain during and after pregnancy.
General Causes of Tailbone Pain
Coccydynia does not only occur in women. Men are also at risk of developing tailbone pain although it is more common in women. Possible causes of and risk factors for tailbone pain in men, women and even children include :
- Injury, particularly impact to the buttock like a kick or falling on the buttock.
- Fracture of the coccyx.
- Excessive pressure on the coccyx with prolonged sitting and long distance cycling.
- Neuritis, especially of the pudendal and sciatic nerves.
- Pilonidal cyst
- Meningeal cyst
- Piriformis syndrome
Many cases of coccydynia occur for no known reason (idiopathic).
Signs and Symptoms of Coccydynia
Tailbone pain (coccydynia) is a symptom itself and not a disease. It is a pain felt between the “cheeks” of the buttock (intergluteal cleft). The pain is worse when sitting backwards and eases with sitting or stooping forward. Bowel movements and intercourse may exacerbate or even trigger the pain in severe cases. Other signs and symptoms apart from the pain may vary depending on the cause and any other underlying conditions of the buttock, vertebral column or pelvis and perineum.
Treatment of Coccydynia
Tailbone pain itself can be treated conservatively with a seat cushion, reducing the sitting time or at least sitting in an appropriate position that reduces weight on the coccyx. Physical therapy may also be helpful.NSAIDs help to reduce the inflammation and control pain. In more severe cases corticosteroid and even anesthetic injections may be necessary. Although extremely rare, surgical removal of the coccyx (coccygectomy) may be considered for patients with severe tailbone pain who do not find relief with other therapeutic measures.