What is the technique for closed reduction of a dorsally displaced fifth digit (finger)?

Dorsal 5th Digit Reduction Technique

For dorsally displaced fifth digit dislocations, attempt closed reduction first using longitudinal traction with the metacarpophalangeal (MCP) joint flexed at 90°, applying volar pressure on the base of the proximal phalanx while stabilizing the metacarpal head—but be prepared for open reduction via a volar approach if closed attempts fail, as complex dislocations with volar plate interposition are common and cannot be reduced by closed means 1, 2.

Initial Assessment and Imaging

Before attempting reduction, obtain 3-view radiographs (PA, lateral, and oblique) to confirm the dislocation type and rule out associated fractures 3. The oblique view is particularly important for phalangeal injuries as it increases diagnostic yield 3.

Closed Reduction Technique

Step-by-Step Approach:

1. Anesthesia: Perform digital block or hematoma block for adequate pain control

2. Positioning:

   • Flex the wrist to relax the flexor tendons
   • Flex the MCP joint to 90° to relax the volar structures

3. Reduction maneuver:

   • Apply longitudinal traction along the axis of the finger
   • Apply volar-directed pressure on the dorsal base of the proximal phalanx
   • Simultaneously push the metacarpal head dorsally with your other hand
   • Avoid hyperextension, which can convert a simple dislocation into a complex one by further entrapping the volar plate

4. Post-reduction:

   • Confirm reduction clinically and radiographically
   • Test joint stability through range of motion
   • Buddy tape to adjacent finger for 2-3 weeks

Critical Pitfall: Complex Dislocations

If closed reduction fails after 1-2 attempts, stop immediately and prepare for open reduction 2. Repeated forceful attempts risk neurovascular injury and soft tissue damage. Complex dislocations occur when the volar plate becomes interposed between the metacarpal head and proximal phalanx, making closed reduction impossible 4, 2.

Signs of Complex Dislocation:

• Puckering of palmar skin
• Palpable metacarpal head in the palm
• Failed closed reduction attempts
• Sesamoid bone visible on radiograph between joint surfaces

Open Reduction (When Closed Fails)

Use a volar approach for complex MCP dislocations 4, 2:

1. Make a vertical or Bruner incision over the affected MCP joint on the volar surface
2. Release the A1 pulley
3. Identify the entrapped volar plate (often with attached sesamoid bone)
4. Use a Freer elevator to gently lever the proximal phalanx back into position
5. Repair the volar plate with absorbable sutures
6. Consider temporary K-wire fixation at 45° for 2-3 weeks if unstable 2

Special Considerations for the Fifth Digit

The fifth finger has unique anatomical features that make complex dislocations more likely:

• Smaller joint size makes volar plate entrapment easier
• Ulnar deviation forces are common in sports injuries 5
• The natatory ligament and superficial transverse ligament can become displaced and block reduction 4

Post-Reduction Management

• Immobilization: Buddy tape for 2-3 weeks for simple dislocations; dorsal splint for complex cases requiring open reduction
• Early mobilization: Begin gentle active range of motion at 2-3 weeks to prevent stiffness 6
• Follow-up radiographs: At 1-2 weeks to confirm maintained reduction

Outcomes

Simple dislocations reduced closed typically achieve excellent outcomes with full range of motion 5, 1. Complex dislocations requiring open reduction can still achieve functional range of motion (0-80° at PIP joint) if treated promptly, though slight limitation and swelling may persist 5, 6, 4.

Key takeaway: The fifth digit's small size and anatomical constraints make it prone to complex dislocations requiring surgical intervention—don't persist with multiple closed reduction attempts when the first one or two fail 2.