What is the preferred plating technique (parallel vs perpendicular) for treating distal humerus fractures?

Parallel Plating is Superior to Perpendicular Plating for Distal Humerus Fractures

Parallel plating configuration provides superior biomechanical stability compared to perpendicular (orthogonal) plating for distal humerus fractures, particularly in osteoporotic bone. 1

Biomechanical Evidence

The most recent and highest quality evidence from a meta-analysis of biomechanical studies demonstrates that parallel plating constructs offer:

• Greater axial stiffness and load to failure
• Higher torsional stiffness
• Superior posterior bending load to failure 1

This biomechanical advantage is particularly important in:

• Osteoporotic bone, where parallel locking systems showed improved stability compared to perpendicular systems 2
• Supracondylar fractures, where parallel constructs demonstrated better torsional stiffness 1

Clinical Outcomes

While biomechanical studies show advantages for parallel plating, clinical outcome studies show comparable results between techniques:

• A prospective randomized trial found no significant differences between orthogonal and parallel plating methods in terms of:
  • Clinical outcomes
  • Mean operation time
  • Union time
  • Complication rates 3

Specific Fracture Considerations

The choice between parallel and perpendicular plating may depend on specific fracture patterns:

• Parallel plating may be preferred for:

  • Fractures at the most distal end of the humerus 3
  • Cases requiring maximum stability in osteoporotic bone 2

• Perpendicular (orthogonal) plating may be preferred for:

  • Coronal shear fractures, where posterior-to-anterior fixation provides additional stability 3

Technical Considerations

When implementing parallel plating:

1. Use locking screws when possible, especially in osteoporotic bone
2. Be aware that parallel systems may be more sensitive to proper technique
3. Consider that some parallel plating systems may produce wear debris from their tapping systems 2

Rehabilitation Protocol

Regardless of plating technique, early mobilization is crucial for optimal functional outcomes:

• Both locking plate systems (parallel and perpendicular) allow for early mobilization in patients with osteoporotic bone 2
• For proximal humeral fractures, most can be treated non-operatively with good functional outcomes 4

Common Pitfalls and Caveats

1. Bone quality assessment: Stability for both constructs appears dependent on bone quality, with perpendicular systems being more sensitive to bone mineral density 2

2. Additional fixation: Consider additional independent interfragmentary screws with perpendicular systems in osteoporotic bone 2

3. Fracture pattern: The specific fracture pattern should influence the choice of plating technique, with parallel plating potentially offering advantages for the most distal fractures 3

4. Surgeon experience: The surgeon's familiarity with a specific technique remains an important consideration in achieving optimal outcomes

In summary, while both techniques can provide adequate fixation, the biomechanical evidence favors parallel plating, particularly in osteoporotic bone and for fractures at the most distal end of the humerus.