Galeazzi Fracture-Dislocation

Galeazzi fracture dislocation is a fracture of the radial shaft, usually in the distal third, with disruption of the distal radioulnar joint (DRUJ). It makes up about 3 to 7% of forearm fractures and is called a fracture of necessity because closed treatment in adults usually fails.

The mechanism is a fall on the outstretched hand with the forearm pronated, or a direct blow to the dorsoradial wrist. Radial fractures within 7.5 cm of the wrist joint line carry DRUJ instability in about 55% of cases, against about 6% for fractures more proximal.

The ulnar head dislocates dorsally in most cases, and volarly in some. In children Galeazzi equivalent injuries include physeal separation of the distal ulna.

Complications are DRUJ instability, malunion, nonunion, loss of forearm rotation, radial sensory and ulnar neuropathy, compartment syndrome, and radioulnar synostosis.

Pathophysiology.

The radius shortens and the proximal pull of brachioradialis and the pronator quadratus tears or displaces the triangular fibrocartilage complex (TFCC). The ulna then loses its stable seat in the sigmoid notch.

Radial shortening of over 5 mm, a base-of-ulnar-styloid fracture, and widening of the DRUJ indicate gross instability, which no cast controls.

Wrist pain and swelling, a prominent or depressed ulnar head ("piano key" sign with ballottement), a deformed forearm, and loss of rotation. Test the median, ulnar and radial sensory nerves, check pulses, and examine the forearm compartments. Ask about elbow pain to exclude a coexisting proximal injury.

• Radiographs of the whole forearm including wrist and elbow, with a true lateral of the wrist.
• Signs of DRUJ disruption: widening of the DRUJ on the anteroposterior view (over 2 mm), a base-of-ulnar-styloid fracture, dorsal ulnar head displacement on the lateral view, and radial shortening of over 5 mm.
• CT of both wrists (comparison) in uncertain subluxation. MRI shows TFCC tears.
• Intraoperative stress testing after radial fixation: ballottement in pronation, neutral and supination.

Differential diagnosis.

• Isolated distal radial shaft fracture without DRUJ injury.
• Monteggia fracture dislocation and both bone forearm fracture.
• Essex-Lopresti injury and TFCC injury.
• Colles or Smith fracture with an ulnar styloid fracture.

Adults.

• Open reduction and fixation of the radius with a 3.5 mm compression plate through a volar approach, restoring length and the radial bow.
• Test the DRUJ in rotation. If it is stable, immobilise in an long arm splint in supination for 4 to 6 weeks.
• If unstable in neutral or supination: fix the base-of-ulnar-styloid fragment with a tension band or screw.
• Alternatively, transfix the DRUJ with two 1.6 to 2.0 mm Kirschner wires from the ulna to the radius proximal to the joint, with the forearm supinated, and remove at 4 to 6 weeks.
• TFCC repair when it is torn.
• An irreducible DRUJ needs open exploration, since tendon (extensor carpi ulnaris) or capsule can lie in the joint.
• Rehabilitation: finger movement at once, active rotation after immobilisation.

Children. Closed reduction and an long arm cast in supination for 6 weeks for most. Unstable injuries: elastic intramedullary nailing or a plate.

Open injury. Intravenous co-amoxiclav 1.2 g every 8 hours (or cefazolin 2 g every 8 hours) within 1 hour of injury.

Continue until 24 hours after wound closure for types I and II, and until 72 hours or 24 hours after soft tissue cover (whichever comes first) for type III. Maximum 3.6 g co-amoxiclav daily; every 12 hours at creatinine clearance 10 to 30 mL/min; check liver tests in courses over 7 days.

For heavy contamination or soft tissue loss add gentamicin 5 mg/kg intravenously once daily for up to 72 hours (creatinine daily, level before the second dose, avoid or extend the interval at eGFR under 60 mL/min/1.73 m2). With severe penicillin allergy use clindamycin 600 mg intravenously every 8 hours (maximum 2.7 g daily) with gentamicin.

Tetanus booster 0.5 mL intramuscularly if the last dose was over 10 years ago, with tetanus immunoglobulin 250 units intramuscularly (500 units if over 24 hours since injury or heavily contaminated) when immunisation is incomplete or unknown. Debride and stabilise within 24 hours.

Analgesia.

• Paracetamol 1 g orally every 6 hours for up to 5 to 7 days (maximum 4 g daily; 3 g daily when weight is under 50 kg or in hepatic impairment).
• Ibuprofen 400 mg orally every 8 hours with food for up to 5 days (maximum 1200 mg daily); avoid with eGFR under 30 mL/min/1.73 m2, peptic ulcer or anticoagulant use.
• Oral morphine 5 to 10 mg every 4 hours as needed for up to 3 days (start 2.5 to 5 mg with age over 75 or eGFR under 30 mL/min/1.73 m2; avoid exceeding 60 mg in 24 hours without senior review); monitor sedation and respiration and prescribe a laxative.
• Children: paracetamol 15 mg/kg orally every 4 to 6 hours (maximum 75 mg/kg daily and not exceeding 4 g daily).
• Children: ibuprofen 10 mg/kg orally every 6 to 8 hours with food (maximum 40 mg/kg daily and not exceeding 2400 mg daily). Give both for up to 5 days.

Monitoring. Radiographs at 2 weeks, 6 weeks and at union (8 to 12 weeks). DRUJ stability and forearm rotation at 6 weeks and 3 months. Nerve function and compartments in the first 48 hours. Wires removed at 4 to 6 weeks.

Referral and escalation. Refer every Galeazzi injury to orthopaedics the same day. Emergency for open fracture, compartment syndrome, neurovascular compromise, or an irreducible DRUJ.

Special groups.

• Older adults: osteoporotic fractures need locking plates, and a bone health assessment follows a fragility fracture.
• Children: Galeazzi equivalent physeal injuries often respond to closed reduction.
• Kidney impairment: avoid ibuprofen, reduce morphine doses and extend gentamicin intervals.