Acceptable Angle in Salter-Harris Type 2 Fracture at Middle Phalanx
For Salter-Harris type 2 fractures of the middle phalanx, angulation should be limited to less than 5 degrees to prevent evident rotational deformity and functional impairment.
Assessment of Angulation
Proper evaluation of these fractures requires:
- Standard 3-view radiographic examination (PA, lateral, and oblique) as recommended by the American College of Radiology 1
- Special attention to:
- Degree of displacement
- Fracture stability
- Rotational deformity
- Coronal plane malalignment
- Presence of clinodactyly
Clinical Significance of Angulation
- Even minimal angulation (5 degrees) can cause clinically evident rotational deformity 2
- Hand stiffness resulting from malunion is one of the most functionally disabling adverse effects of hand fractures 3
- Inadequate treatment may lead to malunion, causing digital overlap during flexion 3
Management Algorithm Based on Angulation
Non-displaced or minimally angulated (<5°):
- Posterior splinting to maintain fracture alignment
- Immobilization for 3-4 weeks
- Regular radiographic follow-up to ensure proper healing
Angulated (>5°) or rotated:
- Requires reduction to restore proper alignment
- Can often be performed under local anesthesia in the emergency department 2
- Post-reduction radiographs to confirm adequate alignment
Irreducible or unstable fractures:
- May require open reduction and internal fixation
- K-wire fixation is commonly used for stabilization 4
Complications of Improper Management
- Rotational deformities after Salter-Harris fractures can be functionally limiting 2
- Delayed treatment beyond 24 hours leads to increased swelling, making reduction more difficult 3
- Growth disturbance is possible but less common in type 2 fractures compared to types 3 and 4
Follow-up and Rehabilitation
- Regular radiographic evaluation to ensure proper alignment during healing
- Once immobilization is removed (typically 3-4 weeks), begin gentle active motion exercises
- Avoid excessively aggressive physical therapy in the postoperative period 3
- Monitor for potential complications such as:
- Malunion
- Growth disturbance
- Joint stiffness
Special Considerations
- Rotational deformities may not be apparent on standard radiographs and require careful clinical examination 5
- For pediatric patients, the prognosis is generally excellent with proper management, with minimal risk of growth disturbance 3
- Diaphyseal constriction may occur in some cases but typically doesn't affect function significantly 4
Remember that accurate clinical examination is essential, particularly checking for rotation of the finger, as radiographs may not always show rotational displacement 5.