Sub-trochanteric Fracture

Subtrochanteric Fracture

Subtrochanteric fractures are proximal femur fractures that occur between the lesser trochanter and a point 5cm distal to the lesser trochanter. This region of the femur experiences high compression and tensile forces, has less blood supply, has a dense cortex that is less prone to healing and has a lot of deforming forces in the proximal fragment. They may occur in the elderly and young patients following low-energy or high-energy mechanisms, respectively. Treatment is usually operative.

Subtrochanteric fractures account for 10% of proximal femur fractures.

Russell-Taylor classification (historical classification based on whether the fracture would be amenable to a standard IM nail (type I) vs. a lateral fixed-angle device (type II)

• Mechanism of injury
  • High-energy mechanism e.g. MVA in young patients
  • Low-energy mechanism e.g. fall from standing heigh in elderly patients
• Deforming forces (proximal fragment)
  • Flexion by psoas
  • Abduction by gluteus medius and minimus
  • External rotation by short rotators
• Patient history
  • Bisphosphonate use (atypical fracture)
  • Thigh pain before fracture
• Signs and symptoms
  • Hip and thigh pain
  • Inability to bear wait
  • Pain with motion
  • Obvious deformity (shortening and varus alignment)
  • Skin tenting (due to flexion of proximal fragment)
• Investigations
  • X-ray (AP and lateral hip, AP pelvis, full length femur including knee joint)
    • Transverse tension component on the lateral side and oblique compression component on the medial side in bisphosphonate related fractures
• Indications for non-operative treatment
  • Non-ambulatory patient
  • Co-morbidites that make the patient unfit for surgery
• Non-operative treatment
  • Rarely used due to strong deforming forces and inability to mobilize without surgery
• Operative treatment
  • Intramedullary nailing (cephalomedullary)
  • Fixed angle plate
• Complications
  • Varus or procurvatum malunion
  • Nonunion