What is the difference in treatment approach between intertrochanteric and subtrochanteric fractures?

Intertrochanteric vs. Subtrochanteric Fractures: Treatment Differences

Intertrochanteric fractures are best treated with sliding hip screws, while subtrochanteric fractures require cephalomedullary nails due to their biomechanical differences and healing characteristics. 1

Anatomical Differences

• Intertrochanteric fractures:

  • Occur between the greater and lesser trochanters
  • Located in cancellous bone with good blood supply
  • Often have significant comminution
  • Can cause substantial blood loss (may exceed one liter) 1

• Subtrochanteric fractures:

  • Occur below the lesser trochanter (within 5cm distal to it)
  • Located in cortical bone with less vascularity
  • Subject to high biomechanical stresses
  • Often have more complex fracture patterns

Treatment Approach Differences

Intertrochanteric Fractures

1. Preferred fixation device:

   • Sliding hip screw for stable intertrochanteric fractures 1
   • Antegrade cephalomedullary nail for unstable intertrochanteric fractures 1

2. Surgical considerations:

   • Shorter surgical time compared to subtrochanteric fixation 2
   • Requires restoration of the medial cortex (Adams arch) for stability 3
   • Allows for earlier weight-bearing when properly fixed

Subtrochanteric Fractures

1. Preferred fixation device:

   • Long cephalomedullary nails are strongly recommended 1
   • Distal locking is necessary, with dynamic locking preferred for axial compression 3

2. Surgical considerations:

   • Longer surgical time compared to intertrochanteric fixation 2
   • More challenging reduction due to deforming muscle forces
   • Greater risk of delayed union or nonunion compared to intertrochanteric fractures 4
   • May benefit from bone grafting to promote healing 4

Biomechanical Considerations

• Subtrochanteric region experiences forces up to 1200 pounds per square inch
• The proximal fragment in subtrochanteric fractures is typically pulled into flexion, abduction, and external rotation by hip muscles 3
• Reduction is more difficult in subtrochanteric fractures due to muscle tension on the proximal fragment 3

Special Considerations for Fractures with Extension

For intertrochanteric fractures with subtrochanteric extension (>2cm below lesser trochanter):

• Long nails show advantages in preserving mobility scores 2
• Standard nails have the advantage of reduced surgical time 2
• Both standard and long nails show comparable outcomes for mortality and complications 2

Postoperative Management

Both fracture types benefit from:

• Early mobilization to reduce complications
• Appropriate pain management
• Antibiotic prophylaxis
• Correction of postoperative anemia 1
• Regular assessment of cognitive function and nutritional status 1

Pitfalls and Caveats

1. Technical errors to avoid:

   • Insufficient reduction
   • Incorrect implant selection or insertion
   • Failure to restore medial cortical support 3

2. Potential complications:

   • Varus collapse (more common in intertrochanteric fractures)
   • Delayed union or nonunion (more common in subtrochanteric fractures)
   • Implant failure (higher risk in subtrochanteric fractures due to higher biomechanical stresses)

3. Management of complications:

   • Pseudoarthrosis or varus malalignment should be managed with valgus osteotomy
   • Femoral head or acetabular damage may require total hip arthroplasty 3

Understanding these key differences between intertrochanteric and subtrochanteric fractures is essential for selecting the appropriate fixation method and optimizing patient outcomes in terms of morbidity, mortality, and quality of life.