Fractures and dislocations of the pelvis and hip joint
The pelvis
The pelvis is a combination of five bones and three joints. These are:
- The bones are the Sacrum, coccyx, illium, ischium and pubis
- The joints are the two sacroiliac joints and symphysis pubis
The pelvis acts to support the pelvic viscera, the symphysis pubis has no notable movement in normal conditions, while the sacroiliac joints can achieve anterior and posterior tilt in the sagittal plane and depression and elevation in the frontal plane with left and right rotation in the transverse plane.
There are important neurovascular structures intimately associated with the posterior pelvic ligaments, and any damage to these carriers with it significant suspicion for injury of internal iliac vessels or lumbosacral plexus.
Patients with pelvic fractures are often at risk from severe bleeding due to the large number of high calibre vessels that pass through this area. In general fractures can be divided into the following:
- Avulsion fractures
- Single bone fractures
- Complex fractures
- Acetabular fractures
Avulsion fractures originate from the adductors, rectus femoris and sartorius muscles and are commonly seen in young athletes. Treatment is based on the severity of the injury and the degree of displacement, larger fragments may require nailing.
Single bone injuries are common in elderly patients with porotic bone or where there has been a well localized area of trauma. Fractures include pubic rami and the wing of the ilium. Occasionally there can be injury to the bladder or urethra. Treatment is early mobilization in uncomplicated injuries.
One common form of single bone injury is the wing of the ilium. The main function of the iliac wing is to provide a firm foundation for muscle attachment and the protection of pelvic contents, a fracture is generally caused by a direct blow or crush injury. Rest is generally sufficient for iliac wing healing, as it is well vasculated.
The pelvis is a ring structure and it is uncommon to be able to break the true ring in a single place, and fractures tend to be multiple, as such these are complex fractures. There are three main fracture patterns in a complex fracture:
- Anterior/posterior compression (open book)
- Side compression
- Vertical compression