Proximal femoral fractures (summary)

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This is a basic article for medical students and other non-radiologists

Proximal femoral fractures are a heterogeneous group of fractures that occur in and around the hip. The commonest type of fracture in this region is the femoral neck fracture.

They can occur anywhere between the joint surface of the femoral head and the upper shaft (proximal diaphysis) of the femur.

Reference article

This is a summary article. For more information, you can read a more in-depth reference articles: proximal femoral fractures, femoral neck fractures.

Summary

  • anatomy
  • epidemiology
    • incidence of 1/1000 in Western populations
    • high incidence of low-energy osteoporotic fractures in the elderly
    • smaller peak in younger patients involved in high-energy trauma
  • presentation
    • painful hip and inability to weight-bear
    • shortened, externally rotated leg
  • pathology
    • division into intracapsular and extracapsular fractures
      • capsular insertion medial to the intertrochanteric line
    • intracapsular
      • femoral head: fractures of the head that extend to the joint
      • femoral neck: extra-articular, intra-capsular fractures
        • subcapital: just below the femoral head (capitis)
        • cervical: across the femoral neck
        • basicervical: at the bottom (base) of the neck (cervical)
    • extracapsular
      • trochanteric: fractures that span the intertrochanteric line
      • subtrochanteric: fractures below the trochanters
  • radiology
    • pelvic with lateral hip radiograph
    • normal radiograph with persistent symptoms needs further Ix
      • CT or MRI can be used to find occult minimally displaced fractures
  • treatment
    • operative management
      • hemiarthroplasty for displaced intracapsular fractures
      • dynamic hip screw if hemiarthroplasty not required
  • prognosis
    • 10% die within 1 month
    • 33% die within 12 months
    • missed or maltreated intracapsular fractures risk avascular necrosis
Relevant anatomy

The hip capsule inserts just proximal to the intertrochanteric line. Blood supply to the femoral head is retrograde and dependent on the femoral neck. A displaced femoral neck fracture may disrupt the blood supply to the femoral head resulting in avascular necrosis.

Radiological features

Diagnosis of a proximal femoral fracture is usually possible on a plain x-ray. The x-ray also allows assessment of the type of fracture and the degree of displacement. Where a patient presents with symptoms of a hip fracture, but the x-ray is normal, additional imaging may be required, e.g. CT or MRI.

Plain radiograph

On the plain film, the fracture should be seen as a lucency that traverses the bone. The affected cortex may be disrupted in which case it will be discontinuous. The simplest way to look for a proximal femoral fracture is to trace the cortex of the femur looking for cortical disruption.

Once you have found the fracture, determine what type of proximal femoral fracture you are looking at:

  • femoral head fracture
  • femoral neck fracture (intracapsular)
  • trochanteric fracture (extracapsular)
Medical student radiology curriculum