Coccyx fracture
The coccyx is illustrated in red at the end of the spine under the pelvic ring

Definition

A fracture of the coccyx involves a break of the lowest portion of the spine also named tailbone, which curves into the pelvic ring.

The coccyx is held together by ligaments that attach it to the pelvic bones

Pathology

The coccyx is a small triangular bony structure formed by 3 to 5 bones held together by ligaments and joints. There are differences in its structure from person to person. The bones of the coccyx are not fused but kept together by ligaments and joints allowing minimal movement. The coccyx is connected to the sacrum by a fibrocartilaginous joint (sacro-coccygeal symphysis). A traumatic fracture to the coccyx results into a pathological condition defined coccydynia (pain, discomfort) that is also common to coccyx dislocation and bruising. Coccyx injuries are more frequent in women as the broader conformation of pelvis exposes the tailbone outwards.

Colles' fracture with bone displacement seen before (left) and after closed reduction (right) in a cast

Classification

The fractures of the distal radius are defined with various classification systems including the AO (Arbeitsgemeinschaft fuer Osteosynthese) system. They relate to the mechanisms of injury and bone fracture characteristics and provide a guideline towards suitable treatments. The most frequent types of distal radius fracture are:

No 1.

Colles’ fracture is the most common type of fracture in which the distal bone of the radius tilts upwards following an outer bending of the wrist as it happens when falling on the hand

Smith’s fracture or reversed Colles’ fracture occurs when the distal portion of the radius tilts downwards following the inward bending of the wrist

Barton fracture is an intra-articular fracture of the distal radius with dislocation of the radiocarpal joint

Chauffeur fracture is an intra-articular fracture of the radial styloid process, also known as Hutchinson fracture or backfire fracture.

Left: Distal radius intraarticular, displaced fracture; Middle: Older distal radius fracture with callus formation; Right: Distal radius and ulna fracture, extraarticular and displaced

No 2.

Intra-articular fracture extends to the wrist joint (or articulation)

Extra-articular fracture is located outside of the wrist joint

Open fracture when bone fragments perforate the skin

Comminuted fracture when the bone breaks into multiple fragments

Non-displaced when the anatomical alignment of the bone is maintained or displaced when the bone fragments move apart.

Melone’s classification describes the characteristics of intra-articular fractures of the radius:

i    Stable fracture

ii    Unstable "die-punch"

iii   "Spike" fracture

iv Split fracture

v   Explosion injuries

Acetabular fracture of the pelvis

Acetabular fractures

These fractures are divided into:

Anterior pillar (not weight bearing part of joint)

Posterior pillar (often associated with dislocation of the hip including the weight bearing part of joint)

Transverse

Comminuted involving both column type 

Sacral / coccygeal fractures

The sacrum is a triangular-shaped bone formed by 5 fused vertebrae, which provide a posterior wall to the pelvic ring. At each side of the sacrum, the ala structures articulate with the ilium bones forming the sacro-iliac joints. Sacral fractures are usually parallel to the spine and can involve the ala. Less frequently sacral fractures may display an “H” shape, including a transversal fracture uniting both sides of the sacrum. Three zones are described where sacral fractures can occur that are along vertical lines relative to the alignment of the foramina. Sacral fractures may result in sacral instability and require treatment via sacroplasty (injection of bone glue into the fracture). Surgery is necessary in case of associated neurological symptoms.

Fractures of the coccyx involve the tailbone, the terminal portion of the spine situated below the sacrum formed by 3 to 5 fused vertebrae. Coccyx fractures occur when falling on a seated position. They are more common in elderly women and seldom require surgical treatment.

A fall on the buttocks may lead to a coccyx fracture

Causes

Coccygeal fractures most commonly ensue in various forms of trauma including:

Fall into a seating position

Direct blow (contact sports)

High pressure on the lower spine when sitting during sport (rowing, cycling, horse riding)

Childbirth

Growth of bone spurs

Unknown causes

Four stages of osteoporosis showing progressive loss of bone material

Risk factors

The risk factors for a fracture to the coccyx are:

Older age

Osteoporosis

Female gender

Reduced muscle mass in the buttocks

Contact sports

Assault

A coccyx fracture causes pain to the lower spine and buttocks

Symptoms

The symptoms resulting from a fracture of the coccyx include:

Pain in the buttock area becoming stronger when sitting, during defecation and intercourse (women)

Tenderness

Bruise

Nausea

X-ray of a fractured coccyx

Diagnosis

The history of the traumatic injury or other events possibly leading to the fracture of the coccyx is usually sufficient to form a diagnosis during medical examination. However, X-ray taken in seated and standing position confirm the presence of a fracture and the occurrence of associated injuries to other levels of the spine. Occasionally a diagnosed fracture of the coccyx is confused with a coccyx dislocation. Rectal and neurologic examination may be carried out if a coccygeal fracture, dislocation and nerve damage are suspected.

Treatment

A couple of days of bedrest is recommended after a coccyx fracture

Nonoperative treatment

A fracture to the coccyx is rarely treated with surgery unless there are severe complications involving the local nerves. Conservative management is standard care for this pathology and is mostly focused on one or two days of bed rest and pharmacological pain control. The prognosis is of approximately 4 to 6 weeks. Additional treatments include:

Non steroidal anti-inflammatory drugs (NSAIDs)

Analgesics (oral administration or local injection)

Laxatives (reduce pain during defecation)

Steroid injection locally (seldom)

Single local nerve block injection

Surgery is seldom and consists in the removal of the coccyx

Surgical treatment

It is very rare to treat the coccyx fracture with surgery. This is only recommended in a severe traumatic destruction of the coccyx or in case of prolonged pain. The procedure involves the removal of the coccyx or coccygectomy.

A ring cushion avoids pressure onto the fractured coccyx and improve comfort

Rehabilitation

A fracture to the coccyx may require a couple of days of bed rest. There are no specific exercises for the rehabilitation. General recommendations for recovery include:

Ice/heat treatment

Antiinflammatory therapy (NSAIDs)

Use of inflated ring or cushion when sitting to alleviate pressure to the coccyx

Calcium and vitamin D administration

Walking – general fitness

Drugs such as Vitamin D, biphosphonates and calcium may help in osteoporotic patients

Prevention

The main prevention is to avoid falls with the use of supporting devices and reduce falling hazards at home and in the work place. Delaying rather than preventing osteoporosis with the administration of the bisphosphonate group of drugs, calcium and vitamin D may also help vulnerable patients.