Classic history and presentation: Acetabular fractures have a bimodal age and sex distribution. A motor vehicle crash or fall from a height can cause an acetabular fracture in any age group. Most acetabular fractures after falling from a standing height occur in older adult women with underlying osteoporosis.
Prevalence: Acetabular fractures are about 3% of all skeletal injuries.
- Age – Bimodal distribution; seen in younger, active adults and individuals older than 65 years.
- Sex / gender – Osteoporotic fractures are more common in women.
- Low bone mass or osteoporosis
- Smoking
- Low-estrogen states in women, such as from a prior hysterectomy or postmenopause
- Older age
- Northern European ethnicity
- Tobacco use
- Conditions that increase the risk of falling, such as alcohol use, prior fracture / fall history, and the use of fall-increasing drugs (eg, sedatives, opioids, dopaminergic agents, and anxiolytics / antidepressants)
Acetabular fractures occur when the femoral head is forcefully driven into the socket, exceeding the strength of the bone. The force's direction and magnitude determine the fracture pattern and could dislocate the hip joint. If the posterior wall is fractured, the hip joint could dislocate posteriorly and injure the sciatic nerve.
Grade / classification system: Most classifications, such as the Letournel classification system, rely on the anatomy and fracture pattern without referring to other factors that affect treatment decisions and outcomes, such as the degree of comminution and bone quality.
Letournel classification to determine the fracture pattern:
- What columns are involved (ie, anterior, posterior, or both)?
- Any separate wall involvement (ie, anterior, posterior, or both)?
- Is there any articular cartilage in continuity to the axial skeleton? (If yes, this is automatically considered a both column injury.)