What is the principle of buttress plating?

Principle of Buttress Plating

Buttress plating is a fundamental fracture fixation technique designed to resist shear forces and prevent displacement of fracture fragments by providing mechanical support perpendicular to the direction of deforming forces, particularly in vertically oriented or metaphyseal fractures where traditional compression techniques are insufficient. 1, 2

Core Biomechanical Principle

The essential concept of buttress plating involves positioning a plate to act as a mechanical barrier that:

• Resists shear forces that would otherwise cause fracture fragment displacement, particularly in vertically oriented fractures where compressive forces alone cannot maintain reduction 1, 2
• Prevents varus collapse by providing lateral or medial support against deforming forces during weight-bearing and muscle contraction 1
• Neutralizes deforming forces without relying on compression across the fracture line, making it ideal for comminuted or vertically oriented fracture patterns 2, 3

Technical Application

Plate Positioning

• The plate is positioned perpendicular to the direction of the deforming force rather than parallel to the bone axis 2
• For vertical femoral neck fractures, a medial buttress plate resists the shear forces that occur with hip motion and weight-bearing 2
• For posterior wall acetabular fractures, superior buttress plating neutralizes shear forces on posterosuperior wall fragments 4

Fixation Strategy

• Screws proximal and distal to the fracture anchor the plate to intact bone, creating a mechanical barrier 1
• The plate itself acts as the primary stabilizing element, with or without screws crossing the fracture fragments 5
• Proximal screws on buttress plates significantly improve anti-shearing ability and reduce stress on the overall construct (increased stiffness by 3.75-8.31% compared to plates without proximal screws) 1

Clinical Applications

Metaphyseal Fractures

• Buttress plates are particularly effective for displaced metaphyseal fractures where large fracture fragments exist and normal bone mineralization is present 3
• This technique offers less tissue dissection and reduced interference with physiologic fracture healing compared to traditional plating 3

Acetabular Fractures

• For posterior wall acetabular fractures, buttress plating alone (without screws through the wall fragment) maintains reduction in 92-94% of cases at average 1.6-year follow-up 5
• Supplemental superior buttress plating improves reduction and better neutralizes shear forces in posterosuperior wall fractures 4

Vertical Femoral Neck Fractures

• Addition of a medial buttress plate to cannulated screws increases construct stiffness and decreases stress on screws and bone compared to screws alone 1
• This combination reduces maximal displacement of internal fixation and interfragmentary motion, critical for preventing fixation failure and varus collapse 1, 2

Key Advantages

• Minimizes soft tissue disruption compared to extensive plating techniques when using screw-wire systems in selected cases 3
• Avoids hardware complications associated with screws placed through fracture fragments, particularly in posterior wall acetabular fractures 5
• Provides immediate mechanical stability without requiring compression across comminuted or vertically oriented fracture lines 2

Critical Technical Points

• Patient selection requires large fracture fragments and adequate bone quality for optimal screw purchase 3
• The use of proximal screws on buttress plates is essential for maximizing anti-shearing ability and preventing re-displacement (reduces stress by 3.41-15.35%) 1
• Buttress plating is most effective when combined with anatomic reduction, as the plate prevents loss of reduction rather than achieving it 2