Unstable pelvic fracture: what it is, emergency care and recovery

The pelvis is not a single bone. Patient.info describes it as a ring of bones in a bowl shape that attaches the legs to the trunk, with the lower end of the spine (the sacrum and coccyx) at the back. The ring protects organs that sit inside it, including the bladder, the womb and ovaries, and parts of the bowel, which is why a pelvic fracture can sometimes also injure one or more of them.

Fractures are described as stable or unstable. In a stable fracture the broken bones are still properly lined up and the ring has kept its shape, usually with a single break. In an unstable fracture there are two or more breaks in the ring and the ends of the broken bones move apart. Patient.info gives 'open book' fractures, in which the pelvis is broken at the front and the back by severe force from the front, and sideways-force fractures as typical patterns.

Fractures can also be open, when injuries to the skin leave the broken bones visible, or closed, when the skin is not broken. Patient.info says open fractures are more serious because infection can easily reach the wound.

Patient.info lists road traffic accidents, crush injuries (for example being run over by a car or rolled on by a horse) and falls from a height as the causes of major pelvic fractures. Fractures caused by high-force or high-speed injuries are often unstable and need urgent hospital treatment, and there may be other associated injuries.

Not every pelvic fracture is dramatic. The same leaflet notes that less severe, undisplaced fractures can happen after falls or trips, particularly when bones are thin because of osteoporosis, so painful but stable fractures are more common in older people. The unstable pattern discussed on this page is the more serious end of the range.

Patient.info says major and unstable pelvic fractures are likely to cause severe pain and shock, meaning a loss of enough blood to cause serious symptoms. Pain may be felt in the pelvis, groin, back, tummy or down the legs. Because the pelvic bones have a rich blood supply they bleed heavily, and the blood may not be visible because it is inside the abdomen. People can look pale and clammy and be seriously unwell, perhaps unconscious.

The leaflet also makes a point that surprises many people: it is sometimes possible to move around, or even try to walk, immediately after a major unstable pelvic fracture, because adrenaline released after an accident can reduce or prevent pain. After significant trauma, a serious pelvic fracture is quite likely even in someone walking around.

• Pain and tenderness in the groin, hip, lower back, buttock or pelvis, worse on moving the hip.

• Bruising and swelling over the pelvic bones, or bruising in the groin, perineum or small of the back.

• Numbness or tingling in the genital area or upper thighs.

• Blood in the urine, blood from the back passage, or vaginal bleeding in women.

• Paleness, clamminess, faintness or drowsiness after a major injury: these are signs of serious blood loss and need an emergency ambulance.

Patient.info advises that anyone with a suspected pelvic fracture should be kept warm, for example by covering them with a jacket, and should not be moved by untrained people, especially if there is severe pain, until help arrives. At a serious road accident, people who are walking around should be asked to sit still, and anyone with pain in or near the pelvis should be assumed to be seriously injured. Call 999 and keep the person still and warm until the ambulance crew arrive.

After major injuries, Patient.info says X-rays of the pelvis are performed urgently, usually from several angles so doctors can see whether and by how much the bones are out of line. A CT scan, which builds a three-dimensional picture from multiple X-ray slices, is used in complicated cases to see the fractures better and to look for associated injuries. MRI is not usually needed except for stress fractures, and ultrasound and contrast studies may be used to assess internal organs.

The British Orthopaedic Association standard states that patients with suspected pelvic fractures from high-energy trauma should have a CT scan with intravenous contrast including head, chest, abdomen and pelvis on admission. It also says potential injury to the bladder or urethra should be suspected, diagnosed and managed, and that a well-applied pelvic binder can mask a serious pelvic ring injury, so a post-binder X-ray is needed after resuscitation.

Patient.info describes the main aims for an unstable fracture as first to stabilise the pelvis and prevent further blood loss, then to keep the bones still so they can heal. The BOA standard sets out the emergency steps for suspected bleeding in more detail.

After the emergency phase, Patient.info says initial treatment is with pain relief and bed rest, followed by mobilisation, and that it is very important to get moving as soon as possible because this is better for long-term recovery and reduces the risk of blood clots. Doctors usually prescribe blood thinners to reduce the risk of clots in the leg and pelvic veins, since pelvic fractures are known to increase it. Crutches or a walker may be needed for several weeks, and physiotherapists and occupational therapists help maintain strength and mobility.

The leaflet says most people who have a pelvic fracture regain full mobility, that recovery is quicker if the fracture is less severe and the person younger and fitter, and that a major pelvic fracture can sometimes affect mobility in the long term. Recovery also depends on other injuries, particularly any damage to the nerves to the legs. Your trauma and rehabilitation team can give a realistic picture for your own injury.

An unstable pelvic fracture is treated as an emergency through the NHS trauma system: ambulance, emergency department or direct transfer to a Major Trauma Centre, then surgery and inpatient rehabilitation. The BOA standard describes this as care within a trauma system with defined referral pathways.

Once the acute phase is over, some people use private physiotherapy or a private orthopaedic opinion for follow-up. These services complement rather than replace the NHS team that holds the operative and imaging records, so it helps to ask for copies of reports and to keep your trauma centre informed.