What is the acceptable degree of dorsal angulation for a Salter-Harris (S-H) type 2 finger fracture?

Acceptable Dorsal Angulation for Salter-Harris Type 2 Finger Fractures

For Salter-Harris type 2 finger fractures, dorsal angulation of less than 10 degrees is generally acceptable for nonsurgical management, while angulation greater than 10 degrees typically requires reduction or surgical intervention. 1, 2

Evaluation and Assessment

• A standard 3-view radiographic examination (PA, lateral, and oblique) is essential for proper evaluation of these fractures 3, 2
• An internally rotated oblique projection increases diagnostic yield for phalangeal fractures 3, 2
• Assessment should include:
  • Degree of displacement
  • Fracture stability
  • Rotational deformity
  • Coronal plane malalignment
  • Presence of clinodactyly 2

Management Based on Angulation

Acceptable Angulation (Conservative Management)

• Angulation <5°: Posterior splinting to maintain fracture alignment with immobilization for 3-4 weeks 2
• Angulation 5-10°: Can be treated with buddy splinting if there is minimal displacement and no rotational deformity 1

Unacceptable Angulation (Requires Intervention)

• Angulation >10°: Requires reduction to restore proper alignment 1
• Rotational deformity: Even 5° of angulation can cause evident rotational deformity, requiring reduction 4

Treatment Approach

1. For acceptable angulation (<10°):

   • Buddy splinting or posterior splinting for 3-4 weeks
   • Regular radiographic follow-up to ensure proper healing 2

2. For unacceptable angulation (>10°):

   • Reduction under local anesthesia, often possible in the emergency department 4
   • Post-reduction radiographs to confirm adequate alignment
   • If reduction is unstable or unsuccessful, surgical intervention with K-wire fixation may be necessary 2

Special Considerations

• Juxtaepiphyseal fractures (occurring 1-2mm distal to the growth plate) present with more angulation and instability than true Salter-Harris type 2 fractures and more frequently require operative fixation (42.9% vs 10.8%) 5
• Recent research shows that children with up to 26° of initial coronal plane angulation in small finger proximal phalanx fractures reported good long-term functional outcomes after nonsurgical management, suggesting that higher degrees of angulation may be acceptable in certain fingers 6
• The proximal phalanx of the small finger may tolerate greater angulation than other digits 6

Monitoring and Follow-up

• Regular radiographic evaluation is necessary to ensure proper alignment during healing 2
• Once immobilization is removed (typically 3-4 weeks), gentle active motion exercises should begin 2
• Monitor for potential complications such as:
  • Malunion
  • Growth disturbance
  • Joint stiffness 2

Clinical Pearls and Pitfalls

• Pearl: Rotational deformity should always be assessed, as even minimal angulation can cause clinically evident rotation 4
• Pitfall: Failing to distinguish between true Salter-Harris type 2 and juxtaepiphyseal fractures may lead to inappropriate treatment decisions 5
• Pearl: Small finger proximal phalanx fractures may tolerate greater angulation than previously thought 6
• Pitfall: Excessively aggressive physical therapy in the postoperative period may increase the risk of fixation failure 2