Coccydynia
Synonyms and keywords: Coccygodynia, coccygeal pain, coccyx pain, coccaglia or (in layperson's terms) buttache.

# Overview
Coccydynia is a medical term meaning pain in the coccyx or tailbone area, usually brought on by sitting.

# Natural History
In many cases the exact cause is not known.
Coccydynia is often reported following a fall or after childbirth. In some cases, persistent pressure from activities like bicycling may cause the onset of coccyx pain.   Coccydynia due to these causes usually is not permanent, but it may become very persistent and chronic if not controlled.
Rarely, coccydynia is due to the undiagnosed presence of a sacrococcygeal teratoma or other tumor in the vicinity of the coccyx.  In these cases, appropriate treatment usually involves surgery and/or chemotherapy.

# Diagnosis
A number of different conditions can cause pain in the general area of the coccyx, but not all involve the coccyx and the muscles attached to it. The first task of diagnosis is to determine whether the pain is related to the coccyx. Physical examination, high resolution x-rays and MRI scans can rule out various causes unrelated to the coccyx, such as Tarlov cysts and pain referred from higher up the spine. Note that, contrary to most anatomical text books, most coccyxes consist of several segments: 'fractured coccyx' is often diagnosed when the coccyx is in fact normal or just dislocated at an intercoccygeal joint  .
A simple test to determine whether the coccyx is involved is injection of local anesthetic into the area. If the pain relates to the coccyx, this should produce immediate relief .
If the anesthetic test proves positive, then a dynamic (sit/stand) x-ray or MRI scan may show whether the coccyx dislocates when the patient sits .
Use of dynamic x-rays on 208 patients who gave positive results with the anesthetic test showed:
- 22% Posterior luxation (partial dislocation of the coccyx backwards when sitting)
- 5%  Anterior luxation (partial dislocation of the coccyx forwards when sitting)
- 27%  Hypermobility (excessive flexing of the coccyx forwards and upwards when sitting)
- 14% Spicule (bony spur) on the coccyx
- 31% Not possible to identify the cause of pain
This study found that the pattern of lesions was different depending on the obesity of the patients: obese patients were most likely to have posterior luxation of the coccyx, while thin patients were most likely to have coccygeal spicules.

# Clinical Features
Activities that put pressure on the affected area are bicycling, horseback riding, and other activities such as increased sitting that put direct stress on the coccyx. The medical condition is often characterized by pain that worsens with constipation and may be relieved with bowel movement. Rarely, even sexual intercourse can aggravate symptoms.

# Non-Surgical Treatment
Since sitting on the affected area may aggravate the condition, a cushion with a cutout at the back under the coccyx is recommended (the donut cushion traditionally recommended by doctors is generally useless for this condition). If there is tailbone pain with bowel movements, then stool softeners and increased fiber in the diet may help. For prolonged cases, anti-inflammatory or pain-relieving drugs may be prescribed. The use of anti-depressants such as Elavil (amiltriptyline) may help alleviate constant pain. Local nerve blocks are often beneficial. Tailbone pain doctors specializing in Physical Medicine and Rehabilitation at New Jersey Medical School have published that sometimes even just a single local nerve block injection at the ganglion impar can give 100% relief of coccydynia when performed under fluoroscopic guidance. Reference Foye 2006

# Surgical Treatment
In rare cases, surgery to remove the coccyx (coccygectomy) may be required.

# Related Chapters
- Ganglion impar
- Coccyx (tailbone)