What is the recommended relocation technique for a 5th digit (little finger) dislocation at the base?

Relocation Technique for 5th Digit Dislocation at the Base

The recommended relocation technique for a 5th digit (little finger) dislocation at the base is closed reduction with longitudinal traction followed by direct pressure on the displaced metacarpal base, with subsequent K-wire fixation if the reduction is unstable.

Anatomy and Mechanism

• 5th digit base dislocations typically involve the metacarpophalangeal (MCP) joint
• These dislocations are relatively uncommon but can lead to significant functional impairment if not properly managed
• Most commonly occur as dorsal dislocations due to hyperextension injury

Assessment

• Obtain radiographs in multiple views (AP, lateral, oblique) to confirm dislocation and rule out associated fractures
• Assess neurovascular status before and after reduction
• Determine if dislocation is simple (reducible) or complex (irreducible)

Relocation Technique Algorithm

For Simple Dislocations:

1. Anesthesia: Administer digital block or regional anesthesia
2. Positioning: Place patient in seated position with arm supported on a table
3. Traction: Apply firm longitudinal traction to the digit in line with the metacarpal
4. Reduction maneuver:
   • For dorsal dislocations: Flex the wrist to relax the flexor tendons
   • Apply direct pressure on the base of the proximal phalanx while maintaining traction
   • Push the base of the proximal phalanx in a volar direction to guide it over the metacarpal head
5. Confirmation: Feel for the characteristic "clunk" of successful reduction
6. Post-reduction assessment: Check stability through gentle range of motion

For Complex/Irreducible Dislocations:

• If closed reduction fails after 1-2 attempts, proceed to open reduction
• A dorsal longitudinal incision provides excellent exposure for reducing complex dislocations 1
• This approach allows visualization of the volar plate, which is often the blocking structure

Immobilization and Follow-up

• For stable reductions: Buddy tape to adjacent digit and begin early range of motion exercises
• For unstable reductions: K-wire fixation followed by immobilization for 3-4 weeks
• Active finger motion exercises should begin immediately following reduction to prevent stiffness 2

Special Considerations

• Ulnopalmar dislocations of the 5th carpometacarpal joint are rare and may require K-wire fixation after closed reduction 3
• Bipolar dislocations (involving both ends of the metacarpal) may require surgical intervention with a palmar approach 4
• Irreducible dislocations often have soft tissue interposition (such as tendons or volar plate) requiring open reduction

Complications to Monitor

• Joint stiffness (most common complication)
• Recurrent instability
• Post-traumatic arthritis
• Malrotation

Rehabilitation

• A directed home exercise program is recommended after the immobilization period 2
• Progressive range of motion exercises should be started as soon as stability allows
• Strengthening exercises once healing is confirmed

The key to successful management is prompt reduction, appropriate stabilization based on post-reduction stability, and early protected motion to prevent stiffness while maintaining the reduction.