Subtrochanteric Fractures

These fractures can occur at any age but are more frequent in younger patents and in the elderly.

Mechanism of Injury

These fractures usually occur as a result of a twisting injury or from direct violence.

Classification

Seinsheimer’s classification (1978) is most commonly used:

• Type 1 - any fracture with less than 2mm displacement
• Type 2 - two part fractures:
• 2A - two part transverse fracture
• 2B - two part spiral fracture with lesser trochanter attached to the proximal fragment
• 2C - two part spiral fracture with lesser trochanter attached to the distal fragment
• Type 3 - three part fractures
• 3A - three part spiral fracture. Third part is lesser trochanter
• 3B - three part fracture. Third part is a butterfly fragment
• Type 4 - four or more fragments
• Type 5 - any fracture with extension into greater trochanter

Clinical Features

They are similar to those of intertrochanteric fractures with the affected leg shortened and externally rotated and the thigh being swollen.

AP and lateral x-rays are needed to confirm the diagnosis: a fracture passing through or below the lesser trochanter.