Is the backslab applied on the dorsal or volar aspect for a Smith fracture?

Backslab Application for Smith Fracture: Volar Aspect Placement

For Smith fractures (volar displacement of the distal radius), the backslab should be applied to the volar aspect of the wrist and forearm to provide appropriate support and counterforce to the fracture displacement.

Rationale for Volar Backslab Placement

Smith fractures are characterized by volar and proximal displacement of the distal fragment, which is the opposite displacement pattern of the more common Colles fracture. The backslab placement must counteract this specific displacement pattern:

• The volar backslab provides direct support to the volarly displaced distal fragment
• It prevents further volar displacement by creating a buttress effect
• It maintains the reduction achieved during manipulation

Technical Application

When applying a backslab for a Smith fracture:

1. Position the wrist in slight extension (dorsiflexion) to counteract the volar angulation
2. Apply the backslab on the volar surface extending from the distal palmar crease to the proximal forearm
3. Ensure the backslab covers approximately 2/3 of the circumference of the forearm
4. Maintain the thumb in a functional position
5. Secure with elastic bandage without excessive pressure

Imaging Considerations

Proper radiographic evaluation is essential before and after backslab application:

• Standard 3-view radiographic examination (PA, lateral, and oblique) is typically sufficient 1
• Evaluate for degree of displacement, fracture stability, and volar tilt
• Post-reduction radiographs should confirm adequate restoration of volar tilt

Special Considerations

• Smith fractures often have a higher tendency for instability compared to Colles fractures 2
• Restoration of normal volar tilt (approximately 11°) is more challenging in Smith fractures 2
• If the fracture is unstable after reduction, surgical intervention with volar plating may be necessary 3
• Type II Smith fractures (according to Thomas classification) and unstable Type III fractures typically require internal fixation rather than conservative management 3

Follow-up Management

• Maintain elevation of the hand to reduce swelling
• Regular wound checks and radiographic evaluation to ensure proper alignment
• Early mobilization once immobilization is removed to prevent stiffness 4
• Monitor for complications such as malunion, which can cause functional limitations

The volar backslab placement for Smith fractures provides the optimal anatomical support to counteract the specific displacement pattern of these fractures, helping to maintain reduction and promote proper healing.