Post-Reduction X-Ray: Purpose, Timing, and Interpretation

A post-reduction radiograph is obtained after closed or open reduction of a fracture or dislocation to confirm anatomic alignment and assess reduction quality.

When Obtained

• Immediate (intraoperative / in ER): Confirm reduction before splinting/casting; allows repeat attempt if inadequate.
• Early follow-up (1–2 weeks): Verify maintenance of reduction, early displacement detection.
• Delayed (6+ weeks): Assess healing, callus formation, hardware position.

What to Evaluate

• Alignment: Angular (varus/valgus, apex), rotational, translational (bayonet apposition acceptable in some).
• Joint congruity: Smooth articular surfaces, no step-off >2 mm.
• Length: Compare to contralateral; shortening >1 cm may need correction.
• Hardware (if ORIF): Position, screw purchase, plate contour.
• Associated injuries: Occult fractures, joint widening (syndesmosis, Lisfranc).

Acceptable Reduction Criteria (General)

• Angulation: <10° (varies by bone/age)
• Translation: <50% cortical width
• Rotation: clinical assessment (no malrotation)
• Articular step-off: <2 mm

If Reduction Inadequate

• Repeat closed reduction (if early, swelling permits)
• Convert to open reduction internal fixation (ORIF)
• External fixation (severe soft tissue injury)

Post-reduction films are mandatory medicolegal documentation and guide subsequent management.