Fractures of the pelvis

Fractures of the pelvis are relatively common in osteoporotic elderly patients. In this age group they are low-energy injuries and may, in fact, be pathological fractures. A careful check should be made for abnormalities which might suggest a benign lyric lesion or a metastatic tumour. In young patients, a pelvic fracture is associated with very high-energy accidents and carry a mortality of up to 20 per cent. This is because of the associated injuries. The pelvis is a stable ring, made up of bones and ligaments. If there is a displaced fracture of the pelvis then it must be broken in at least two places, and the ring is likely to be unstable. Unstable pelvic fractures carry a very poor prognosis because they are associated with torrential retroperitoneal bleeding from the pelvic veins. Immediate temporary stabilisation of the pelvic ring may be life-saving by helping the pelvic veins to clot off through tamponade, and by reducing the chance of movement displacing the clot. Pelvic fractures are also associated with damage to the rectum, the vagina and the urethra (especially in the male). A careful examination of all these structures should be performed in any patient with a significant pelvic fracture.

Classification of pelvic fractures

  Fractures outside the ring

These fractures do not disrupt the structure of the ring and occur either following a direct blow or as a traction injury of an epiphysis. In fractures of the sacrum a careful check should be made for nerve damage as the sacral nerves are likely to be involved.

Fractures of the coccyx can occur when the patient falls on to their backside. The fracture is very painful but usually settles after a few weeks. If it does not, then treatment is very difficult as coccydynia (pain in the coccyx) seems to be associated with a neurotic personality. Neither injection of the fracture site with local anaesthetic and steroids nor excision of the coccyx reliably relieves the pain.

Traction injuries

The origin of rectus femoris can be avulsed when, for example, a patient kicks a heavy wet football. Similarly, in Fig. 23.1 the adductor tubercle can be avulsed if the leg is forcibly abducted. Both of these fractures settle with rest.

Fracture of the iliac wing

The iliac wing can be broken following direct trauma, or indeed when harvesting bone graft (Fig. 23.1). No active treatment is necessary.

Single fractures of the ring

These fractures are by definition undisplaced and commonly occur either through the pubic or ischial ramus (Fig. 23.2). They are common in the elderly following a fall and may be pathological, through a metastasis or even a lytic lesion created by hyperparathyroidism (Brown tumour).

Fractures in or around the acetabulum

A fall from a great height on to the feet or a direct blow to the greater trochanter can fracture the pelvis around the acetabulum. The femoral head can be driven centrally through the floor of the acetabulum into the pelvis (the central acetabular fracture) (Fig. 23.3). Alternatively, either the front wall (the anterior pillar) or the back wall (the posterior pillar) of the acetabulum can be fractured. In extreme cases a combination of these injuries occurs. A simple anteroposterior (AP) and lateral view of the pelvis does not reveal the true nature of the injury, and it is usual to take oblique X-rays which show more clearly the extent of the injury to the anterior and posterior pillar. Computerised tomography (CT) scans with three-dimensional reconstruction can give even further information about the nature and extent of the fracture, and the number and extent of displacement of the fragments. This information is important for planning the treatment. If there is damage to the posterior pillar of the acetabulum then a careful check must be made for damage to the sciatic nerve which runs close to the posterior pillar (Fig. 23.4).

Treatment. Fractures around the acetabulum can be treated nonoperatively with skeletal traction for 6—8 weeks. Although this method of treatment is uncomplicated and safe, the results are poor if there is a displaced intra-articular fracture.

Traumatic osteoarthritis of the hip is inevitable, and subsequent treatment with an arthrodesis or even a joint replacement will be required within a few years. This may, however, be the only option if the patient’s overall condition is so poor that major surgery is dangerous, or if the relevant surgical expertise is not available. The alternative is surgical reconstruction of the pelvis using plates bent to the contour of the surface of the pelvis and screws to stabilise fractures. This type of surgery is both difficult and complex, and carries a significant morbidity and mortality to the patient through blood loss and damage to the nerves around the pelvis. If, however, a stable congruent surface to the acetabulum can be recreated the prognosis to the patient is very good indeed.

Double fractures of the ring

Displaced fractures of the pelvis must by definition involve a fracture through two parts of the pelvic ring. It is not always possible to see the second fracture line as it may pass through the sacral iliac joint. These fractures are very high energy and are intrinsically unstable (Fig. 23.5). They are associated with a high mortality because of associated injuries and the massive retroperitoneal haemorrhage involved. Therefore for the reasons described above, they may need stabilising immediately with an external fixator to reduce haemorrhage when the patient is turned (Fig. 23.6).

They are also associated with damage to the nerves of the sacral plexus as well as injuries to the pelvic organs, particularly the male urethra.

Treatment. Initially these patients may be too sick to embark on a formal reduction and stabilisation of the pelvic ring (Fig. 23.7). The operation therefore may have to be delayed for up to 10 days. Beyond that the operation becomes difficult because callous formation prevents fracture reduction.