Is a cross-table lateral view necessary in fracture of the neck of femur (FNF)?

Cross-Table Lateral View in Femoral Neck Fractures

A cross-table lateral view is necessary in femoral neck fractures (FNF) as it provides critical information about posterior displacement and fracture stability that can significantly impact treatment decisions and patient outcomes. 1

Importance of Cross-Table Lateral View

Standard Imaging Protocol

• The American College of Radiology recommends a complete initial radiographic assessment that includes:
  • Anteroposterior (AP) view of the pelvis
  • Cross-table lateral view of the affected hip 1

Critical Information Provided by Lateral View

1. Fracture Displacement Assessment

   • Lateral view can detect posterior displacement/tilt of the femoral head that may not be visible on AP view
   • Strong correlation between posterior displacement on lateral radiographs and actual 3D displacement (correlation coefficient of 0.86, p < 0.001) 2
   • Posterior tilt >20° is associated with increased risk of treatment failure after internal fixation 2

2. Fracture Stability Evaluation

   • Helps identify posterior comminution, which is a key indicator of instability
   • Assists in determining Pauwels classification (fracture angle), which influences fixation choice 3

3. Detection of Lipohemarthrosis

   • A cross-table lateral view with a horizontal beam enables visualization of lipohemarthrosis, which is frequently seen with intra-articular fractures 4

Impact on Treatment Decision-Making

The lateral view directly influences treatment decisions by:

1. Guiding Fixation vs. Replacement Decision

   • Identification of displacement patterns that predict higher failure rates with fixation
   • Detection of posterior comminution that may necessitate arthroplasty over fixation 3

2. Implant Selection

   • Helps determine appropriate fixation method (e.g., sliding hip screws vs. cannulated screws)
   • Sliding hip screws are preferable for displaced/unstable fractures (Pauwels II-III, posterior comminution) 3

3. Surgical Planning

   • Provides information on reduction requirements and approach
   • Helps predict potential complications based on fracture pattern 1

Potential Limitations and Controversies

Some studies have questioned the routine use of lateral views:

• A 2012 study suggested that lateral view did not change management in the majority of cases 5
• A 2008 study found that lateral views changed classification in only 1 of 100 cases and did not alter management plans 6

However, these studies have limitations in sample size and do not address the importance of lateral views in specific fracture patterns, particularly Garden type I and II fractures where posterior tilt assessment is crucial 2.

Best Practice Recommendations

1. Always include cross-table lateral view in initial imaging assessment of suspected femoral neck fractures 1
2. Pay particular attention to posterior tilt in Garden type I and II (non-displaced) fractures, as this may change management 2
3. Do not omit lateral view even when AP view shows a fracture, as the lateral view can change treatment decisions in some cases 1
4. Include the pelvis in initial imaging to detect associated pelvic fractures 1

The cross-table lateral view remains an essential component of femoral neck fracture evaluation, providing complementary information to the AP view that can significantly impact treatment decisions and patient outcomes.