What are the guidelines for performing femur intramedullary (IM) nailing?

Guidelines for Femur Intramedullary (IM) Nailing

Intramedullary nailing is the preferred method for treating fractures of the femoral shaft, with specific technical considerations required to optimize outcomes and minimize complications. 1

Patient Assessment and Preparation

• Evaluate the entire bone length before decision-making to avoid missing femoral neck lesions 2
• For metastatic disease, assess:
  • Life expectancy
  • Mental status
  • Mobility status
  • Pain level
  • Metabolic status
  • Skin condition
  • Nutritional status 2
• For patients with metastatic disease, obtain a long bone survey or bone scan within 2-3 months to detect other sites of disease that may affect weight bearing 2

Technical Considerations for IM Nailing

Entry Point Selection

• Two viable starting points for antegrade nailing:
  • Piriformis fossa
  • Greater trochanter 1
• Retrograde nailing is an alternative approach with specific indications 1

Patient Positioning

• Patient positioning affects ease of nailing and incidence of malalignment 1
• Consider lateral decubitus position for better control of femoral rotation 3
• Proper positioning allows for better visualization of the femoral neck axis, distal locking holes, and femoral condyles 3

Surgical Technique

For Standard Femoral Shaft Fractures:

1. Ensure appropriate nail selection based on fracture pattern and anatomy
2. Consider anterolateral bowing of the femur when selecting and inserting the nail 4
3. Allow immediate weight bearing after IM nailing as this does not affect fracture union rates or implant failure 5

For Metastatic Lesions:

1. For diaphyseal metastatic lesions, there is no advantage to routine use of cephalomedullary nails as there is no high frequency of new femoral neck lesions after IM nailing 2
2. For peritrochanteric fractures with metastatic disease, consider arthroplasty instead of IM nailing 2

Special Considerations for Cemented Procedures

When cement is used during the procedure (such as in some cases with metastatic disease):

1. Communication between surgeon and anesthesiologist is critical:

   • Surgeon must inform anesthesiologist before cement insertion
   • Anesthesiologist must confirm awareness 2

2. Surgical technique for cement application:

   • Thoroughly wash and dry the femoral canal
   • Use a pressurized lavage system to clean endosteal bone
   • Apply cement in retrograde fashion using a cement gun with suction catheter and intramedullary plug
   • Avoid vigorous pressurization in high-risk patients 2

3. Anesthetic monitoring:

   • Maintain vigilance for signs of cardiorespiratory compromise
   • Use arterial line or non-invasive automated blood pressure monitoring
   • Aim for systolic blood pressure within 20% of pre-induction value
   • Prepare vasopressors for potential cardiovascular collapse 2

Complications and Prevention

• Monitor for bone cement implantation syndrome (BCIS) during cemented procedures:

  • Grade 1: Arterial saturation <94% or >20% fall in systolic BP (~20% incidence)
  • Grade 2: Arterial saturation <88% or hypotension >40% fall in systolic BP (~3% incidence)
  • Grade 3: Cardiopulmonary resuscitation required (~1% incidence) 2

• Watch for rotational malalignment, which remains a common complication 3

• Use radiological techniques to control femoral torsion intraoperatively 3

Post-operative Management

• Weight bearing as tolerated can be allowed immediately after IM nailing, regardless of nail size or fracture pattern 5
• Monitor for nonunion, which occurs in approximately 14.7% of cases, with OTA32B fractures having the highest risk 5
• Failure of interlocking screws occurs in approximately 4.4% of cases and is more common with older patients, osteoporotic bone, and larger diameter nails 5

By following these guidelines, IM nailing of diaphyseal femur fractures provides stable fixation with high union rates and low complication rates when vigilance is maintained during preoperative planning, the surgical procedure, and the postoperative period.