How should a hyperextended injury to the fifth digit be initially managed?

Management of Hyperextended Pinky Finger Injury

Buddy strapping to the adjacent ring finger for one week is the most effective initial treatment for hyperextended pinky finger injuries without fracture. 1

Initial Assessment and Imaging

Obtain three-view radiographs (posteroanterior, lateral, and oblique) of the affected finger to exclude fracture or avulsion injury. 2 Standard two-view examinations are inadequate for detecting finger fractures, and the oblique view significantly increases diagnostic yield for phalangeal injuries. 2

• Look specifically for avulsion fractures at the volar plate insertion on the middle phalanx, which indicate more severe capsular injury 3
• Assess for bony mallet injuries (avulsion at the distal interphalangeal joint extensor insertion), as fragments involving >1/3 of the articular surface require operative fixation 2
• Check for palmar displacement of the distal phalanx or interfragmentary gaps >3mm, both surgical indications 2

Treatment Algorithm Based on Radiographic Findings

For Injuries WITHOUT Fracture (Most Common)

Apply buddy strapping to the ring finger for 7 days, allowing immediate gentle range of motion. 1 This approach achieves:

• Earlier recovery of motion compared to rigid splinting 1
• Faster resolution of edema and pain 1
• Equivalent final outcomes to aluminum orthosis immobilization 1

The buddy strapping technique allows the injured finger to move with its neighbor, providing dynamic support while preventing hyperextension recurrence. 1

For Injuries WITH Volar Plate Avulsion Fracture

Immobilize in 15° of flexion using an extension-blocking splint for one week, followed by progressive mobilization. 3, 1 This prevents the two major late complications:

• Chronic post-traumatic hyperextension deformity 3
• Flexion contracture (paradoxically occurs from inadequate initial treatment) 3

For Severe Volar Plate Rupture (Rare)

If physical examination reveals gross instability with easy dorsal subluxation of the middle phalanx despite attempted flexion positioning, surgical repair should be considered in the acute phase. 3 However, most hyperextension injuries can be managed conservatively. 3

Critical Follow-Up Protocol

Reassess at 1 week to ensure proper healing trajectory and adjust treatment. 1 Continue weekly assessments for the first month, then at 3,6, and 12 months. 1

• Monitor for development of flexion contracture, which requires immediate intensive physiotherapy 3
• If presenting >7 weeks after injury with established contracture, initiate splinting and exercise therapy even though outcomes are less predictable 3

Common Pitfalls to Avoid

Never immobilize hyperextension injuries in full extension, as this fails to protect the healing volar plate and increases risk of chronic hyperextension deformity. 3

Do not rely on two-view radiographs alone, as oblique views are essential for detecting subtle phalangeal fractures that alter management. 2

Avoid prolonged rigid immobilization beyond one week in simple hyperextension injuries, as this delays functional recovery without improving outcomes compared to buddy strapping. 1

Do not dismiss injuries presenting late (>7 weeks) - conservative treatment with splinting and physiotherapy can still improve chronic flexion contractures, though results are less predictable than acute management. 3

Age Considerations

Pediatric patients with hyperextension injuries demonstrate superior outcomes compared to adults, with faster recovery and better final function. 1 However, the same treatment principles apply regardless of age. 1