Coccydynia

Coccydynia or Coccygodynia
Classification and external resources
Specialty	rheumatology
ICD-10	M53.3
ICD-9-CM	724.79
DiseasesDB	32571
eMedicine	pmr/242
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Coccydynia is a medical term meaning pain in the coccyx or tailbone area, usually brought on by sitting too abruptly.

Coccydynia is also known as coccygodynia, coccygeal pain, coccyx pain, or coccalgia.

Coccydynia occurs in the lowest part of the spine, the coccyx, which is believed to be a vestigial tail, or in other words the “tail bone”. The name coccyx is derived from the Greek word for cuckoo due to its beak like appearance. The coccyx itself is made up of 3 to 5 vertebrae, some of which may be fused together. The ventral side of the coccyx is slightly concave whereas the dorsal aspect is slightly convex. Both of these sides have transverse grooves that show where the vestigial coccygeal units had previously fused. The coccyx attaches the sacrum, from the dorsal grooves with the attachment being either a symphysis or as a true synovial joint, and also to the gluteus maximus muscle, the coccygeal muscle, and the anococcygeal ligament.

There are four different orientations for the coccyx, as described by Postacchini and Massobrio. In type I the coccyx is curved anteriorly with its apex facing downward and caudally. In type II this forward curvature is more dramatic and the apex extends forward. Type III is where the coccyx angles forward sharply. Lastly, type IV is characterized by the coccyx being subluxated at the sacrococcygeal joint.

There are common pathophysiological ways that a person may develop coccydynia. The two main causes for this condition are sudden impact due to fall, and coccydynia caused by childbirth pressure in women. Other ways that coccydynia develops are partial dislocation of the sacrococcygeal synchondrosis that can possibly result in abnormal movement of the coccyx from excessive sitting, and repetitive trauma of the surrounding ligaments and muscles, resulting in inflammation of tissues and pain.

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