Summary

A Galeazzi fracture-dislocation is a fracture of the Distal Third of the Radius with an associated dislocation of the Distal Radioulnar Joint (DRUJ). It is classically termed a "Fracture of Necessity" because it is inherently unstable and requires surgical fixation (ORIF) in all adults. The mechanism is usually a fall on an outstretched hand (FOOSH) with the forearm in pronation. The radius shortens, causing the ulnar head to dislocate dorsally (Piano Key Sign). Failure to recognize the DRUJ injury leads to chronic pain and loss of rotation. [1,2]

Key Facts

• Mnemonic: GRIMUS.
  • Galeazzi: Radius fracture, Inferior (Distal) dislocation.
  • Monteggia: Ulna fracture, Superior (Proximal) dislocation.
• Pathophysiology: Radius shortens -> Ulna becomes relatively long -> TFCC tears -> Ulnar head pops out.
• Stability: The DRUJ is stabilized by the TFCC. If the fracture is within 7.5cm of the joint, the Interosseous Membrane (IOM) is also usually torn.

Clinical Pearls

"The Piano Key Sign": In a Galeazzi fracture, the ulnar head is prominent dorsally at the wrist. If you press it down, it springs back up (like a piano key) because the stabilizing ligaments (TFCC) are torn.

"Reduce the Radius, Reduce the Joints": Because the DRUJ dislocation is driven by radial shortening, anatomically plating the radius to length often spontaneously reduces the DRUJ.

"Cast in Supination": Pronation forces the radius to cross over the ulna, which tends to displace the fracture. Supination makes the bones parallel and tightens the IOM, stabilizing the DRUJ.

                 GALEAZZI FRACTURE
                        ↓
             ADULT OR CHILD?
             ┌──────────┴──────────┐
           CHILD                 ADULT
             ↓                     ↓
        NON-OPERATIVE         OPERATIVE (ORIF)
      (Long arm cast)         (Plate Radius)
      (Supination)                 ↓
                               CHECK DRUJ
                               STABILITY
                           ┌───────┴───────┐
                        STABLE          UNSTABLE
                           ↓               ↓
                     EARLY PROTOCOL   SUPINATION
                      (ROM 2w)        CAST (6w)
                                           ↓
                                     STILL UNSTABLE?
                                           ↓
                                     K-WIRE DRUJ
                                      (Transfix)

1. Surgical Fixation (The Rule for Adults)

• Principle: Anatomical reduction of the radius restores the alignment of the DRUJ.
• Implant: 3.5mm LCP (Locking Compression Plate) or DCP.
• Approach: Volar (Henry) approach is standard.
• Sequence:
  1. Fix Radius (Restore length).
  2. Check DRUJ stability (Ballottement/Piano Key).
     • Stable: No further action.
     • Unstable: Immobilize in Supination (sugar tong splint) for 6 weeks.
     • Grossly Unstable: Transfix DRUJ with K-wires (Radius to Ulna) for 4-6 weeks.

2. Paediatric Management

• Difference: Periosteum is thick. Ligaments are stronger than bone (Physis fails first).
• Treatment: Closed Reduction and Long Arm Cast.
• Position: Supination (Untwists the radius).

The "Fracture of Necessity"

• Historical cohorts showed >90% failure rate with casting in adults.
• Muscle forces (Pronator Quadratus, Brachioradialis) constantly pull the radius into shortening/angulation, redislocating the DRUJ.

Retzlaff et al.

• Demonstrated that plating the radius alone stabilizes the DRUJ in >80% of cases without needing specific ligament repair.

What is a Galeazzi Fracture?

You have broken the radius bone in your forearm, and because the bone shortened, it pulled the other bone (ulna) out of its joint at the wrist.

Why do I need surgery?

In adults, this fracture is notoriously unstable. If we put it in a cast, the strong muscles in your arm will pull the bones apart again. We need to plate the radius to hold it out to length, which allows the wrist joint to pop back into place.

The Wire (If needed)

Sometimes, the wrist joint is so wobbly that even after fixing the bone, it pops out. We might put a temporary wire through the two bones to lock them together for 6 weeks. This stops you turning your palm, but it allows the ligaments to heal.

Q1: What is the mnemonic for Galeazzi vs Monteggia? A: GRIMUS. Galeazzi = Radius fracture, Inferior (Distal) dislocation. Monteggia = Ulna fracture, Superior (Proximal) dislocation. Or MUGR (Monteggia Ulna, Galeazzi Radius).

Q2: How do you assess DRUJ stability intra-operatively? A: After rigid fixation of the radius:

1. Check anatomical reduction (length/rotation) on fluoroscopy.
2. Take the wrist through full range of Pronation/Supination.
3. Perform the "Piano Key" test (Ballotte the ulnar head) in neutral, pronation, and supination.
4. If it springs up (unstable) -> K-wire.

Q3: Why is the position of immobilization Supination? A: In pronation, the radius crosses over the ulna, and the Interosseous Membrane is lax. In Supination, the bones are parallel (maximal space) and the IOM is tensioned, providing stability to the DRUJ.

(End of Topic)