Coccydynia

Coccydynia refers to pain in and among the area of the coccyx. It is characterised by coccygeal pain which is typically provocated by pressure. It may remain unclear in origin owing to the unpredictability of the source of pain 1.

No accurate data about the frequency of coccydynia is reported but may account for <1% of all backache. It is approximately five times more common in females than males. 

As the name suggests, pain is considered to be the primary symptom of coccydynia. However, pain is extremely varied and may be related to sitting, bowel movements, radiculopathic or generalised coccygeal pain. The coccyx may be tender on examination. 

 Coccydynia can be classified into:

  • idiopathic (most common)
  • secondary coccygeal pain
    • abnormal mobility of the tailbone:
      • hypermobility  
      • rigid coccyx with abnormal features at its tip
      • anterior and posterior subluxation of the coccyx 7   
      • unstable or dislocating coccyx is the 
    • morphological abnormality of the coccyx:
      • coccyx scoliotic deformity
      • increased intercoccygeal angle
    • trauma
      • post falls
      • childbirth
      • partial dislocation of the sacrococcygeal synchondrosis
    • tumor, e.g. chordomaschondrosarcoma
    • inflammation/infection of the coccyx (rarely)

Coccydynia is essentially a clinical diagnosis, but imaging modalities are helpful in assessment and possible identification of the aetiology.

Considered the first line of imaging of painful coccyx ref required. Two types of radiographs:

  • standard radiograph
    • coccyx scoliotic deformity (AP and lateral)
      • number and morphology of coccygeal segments
      • intercoccygeal angle ( between the first and last segment of the coccyx)
      • in idiopathic coccydynia was greater than that of traumatic
      • useful radiological assessment to evaluate the anterior angulation of the coccyx and its deformity
      • normal pivot of the coccyx lies between 5 and 25°
        • < 5° this means immobility or better say rigid mobility.
        • > 25° this means hypermobility 7
  • dynamic stress films or weight bearing radiograph
    • sitting and standing positions.
    • superior than standard radiograph because it can detect measurement of the sagittal rotation of the pelvis and the coccygeal angle of incidence

Described features include ref required:

  • rigid coccyx with a spicule or spur at its tip
  • bursa along the dorsal surface of the coccyx
  • presence of fluid collection within the sacrococcygeal synchondrosis
  • large draining vein on the ventral coccyx
  • any inflammation or soft tissue abnormalities around the coccyx

Conservative treatment includes rest, coccygeal cushion, physiotherapy and massage. In traumatic coccydynia the joint may heal spontaneously over weeks or months

Interventions include:

  • injections of local anaesthetic and steroid
  • radiofrequency ablation of coccygeal discs and Walther ganglion
  • removal of the coccyx by surgery either partial or total (coccygectomy) in refractory cases
    • limited coccygectomy may to resect a mobile segment 5

The word coccyx originates from the Greek word "cuckoo" (kokkyx), on the basis of resemblance to the structure a cuckoo's beak. The term was used in practice for the first time by Simpson in 1859, although was described as early as 1600s. It is also called the "tailbone" because it is located anatomically at the end of the vertebral column below the sacrum.

Causes of pain in the coccygeal region include:

Share article

Article information

rID: 31409
Section: Gamuts
Synonyms or Alternate Spellings:
  • Tail bone pain
  • Coccygodynia
  • Sacrococcygeal joint pain
  • Coccygeal pain
  • Coccyx pain
  • Coccalgia
  • Os coccygis pain

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 1: with anterior angulation of coccyx
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.