Galeazzi Injury — Distal Radius + DRUJ Disruption

The Galeazzi fracture-dislocation is a fracture of the RADIAL SHAFT combined with DISRUPTION of the DISTAL RADIOULNAR JOINT (DRUJ). It is the radius-equivalent of the Monteggia injury (which involves the ulna + proximal radioulnar joint). The injury is named after Ricardo Galeazzi, who described it in 1934, although it was earlier described by Cooper in 1822 and Piedmont in 1920 (hence the historical name `Piedmont fracture` in some American texts). Like the Monteggia, the Galeazzi injury is important because the joint component (the DRUJ dislocation) is frequently missed — only the radial shaft fracture is treated while the DRUJ disruption is ignored, leading to chronic pain, loss of rotation, and DRUJ instability. The principle `fracture of necessity` (Campbell 1941) summarises the management: the radius fracture NECESSITATES operative management because closed reduction cannot be maintained in adults.

• Anatomy of the DRUJ: the distal radioulnar joint (DRUJ) is the articulation between the sigmoid notch of the distal radius and the ulnar head; it allows forearm rotation (pronation/supination); it is stabilised by: (1) the triangular fibrocartilage complex (TFCC) — the primary stabiliser of the DRUJ; (2) the joint capsule (dorsal and volar DRUJ capsular ligaments — the dorsal and palmar radioulnar ligaments); (3) the ulnocarpal ligaments; (4) the extensor carpi ulnaris (ECU) tendon with its subsheath; disruption of the TFCC and DRUJ capsule occurs in all Galeazzi injuries — the DRUJ is unstable after the radial shaft fracture unless the TFCC heals after anatomical reduction and fixation of the radius
• Mechanism: a fall onto an outstretched hand with the forearm in HYPERPRONATION — the axial load is transmitted through the hand to the forearm, and as the forearm continues to pronate, the distal ulna is driven dorsally (displacing the DRUJ) while the radial shaft fractures; the fracture is typically in the middle or distal third of the radial diaphysis; alternatively, a direct blow to the dorsal-radial aspect of the wrist; the `distal third` location of the radial fracture combined with dorsal DRUJ dislocation is the classic Galeazzi pattern

• Radiological assessment: on the AP wrist X-ray — the DRUJ should be assessed for widening of the DRUJ space (>2 mm suggests instability); the ulnar styloid is commonly fractured (the TFCC avulses the ulnar styloid from its base — a large base-of-styloid fracture is associated with DRUJ instability); increased ulnar variance (the ulna appears longer than the radius after radial shortening from the fracture); the radial shaft fracture is typically in the middle or distal third; on the lateral wrist X-ray — the ulna head appears prominent dorsally or volarly (dorsal dislocation of the ulna is most common = the ulna appears dorsal to the radius at the DRUJ level; volar dislocation is rare)
• Clinical indicators of DRUJ disruption: prominence and tenderness of the ulnar head at the DRUJ; pain with forearm rotation (the DRUJ is the pivot on which the distal radius and hand rotate around the ulnar head — any disruption causes pain with rotation); `piano key sign` — dorsal-volar instability of the ulnar head when it is manually balloted; compare with the contralateral side; assess after radial shaft ORIF (if the DRUJ instability persists after anatomical radial fixation → TFCC/DRUJ requires repair)

While the Bado classification is primarily used for Monteggia injuries, it was also applied (in a modified form) to describe the DRUJ displacement direction in Galeazzi injuries. More commonly, Galeazzi injuries are described by the direction of DRUJ dislocation and the radial fracture level.

• The `fracture of necessity` principle (Campbell 1941): the Galeazzi injury in adults CANNOT be managed conservatively — it MUST be operated; the key reason: the deforming forces of the forearm muscles (brachioradialis, extensor carpi radialis longus and brevis, pronator teres) displace the radial fragment and prevent maintenance of reduction with a cast; non-operative management results in malunion of the radius and chronic DRUJ dislocation in virtually all cases; the treatment is ALWAYS ORIF of the radial fracture (anatomical reduction + plate fixation) followed by assessment and treatment of the DRUJ
• Surgical sequence: (1) ORIF of the radial shaft fracture — a 3.5 mm DCP or LC-DCP plate applied along the volar (Henry) or dorsal surface of the radius; the volar Henry approach (between brachioradialis and FCR) is most commonly used for distal and middle third radial fractures; anatomical reduction of the radius restores the normal anatomy and often reduces the DRUJ; (2) DRUJ assessment under fluoroscopy after radial fixation — the forearm is rotated under image intensifier; if the DRUJ reduces and is stable throughout the full range of pronation/supination → no further DRUJ treatment is required; if the DRUJ remains unstable or subluxed → DRUJ repair is required
• DRUJ management after radial ORIF: (1) Stable DRUJ after radius ORIF → above-elbow cast in supination for 4–6 weeks (supination tightens the dorsal DRUJ capsule and the volar TFCC, maintaining DRUJ stability while healing occurs); (2) Unstable DRUJ despite anatomical radius ORIF → repair options: (a) TFCC repair (suture repair of the TFCC through a 2.0 mm bone anchor in the sigmoid notch — for ulnar-sided TFCC tears); (b) Ulnar styloid fixation — if the ulnar styloid is fractured at the BASE (where the TFCC inserts), the DRUJ is likely unstable; fixing the large ulnar styloid base fracture with a tension band or lag screw restores the TFCC attachment and stabilises the DRUJ; (c) Temporary trans-DRUJ K-wire — two crossing K-wires hold the DRUJ in the reduced position for 4–6 weeks while the TFCC heals; this is the most common emergency DRUJ stabilisation technique

• Galeazzi injury: radial shaft fracture + DRUJ disruption; `fracture of necessity` = adults must have ORIF; fracture is typically in the middle or distal third of the radius; dorsal DRUJ dislocation most common (85%); ulnar head is dorsal on the lateral wrist X-ray
• Mechanism: hyperpronation (axial load + forced pronation); axial load transmits through radius → shortens radius → DRUJ disrupts; forearm muscle deforming forces prevent conservative reduction
• DRUJ stability assessment after radius ORIF: mandatory under fluoroscopy; rotate the forearm through full arc; if DRUJ stable → above-elbow cast in supination; if DRUJ unstable → TFCC repair or trans-DRUJ K-wire or ulnar styloid fixation
• Ulnar styloid fracture base: if the base of the ulnar styloid is fractured, the TFCC attachment (at the base of the styloid) is disrupted → DRUJ likely unstable; large base fractures should be fixed (tension band or screw) to restore TFCC attachment and DRUJ stability
• Galeazzi vs Monteggia comparison: Galeazzi = RADIUS shaft + DISTAL radioulnar joint (DRUJ) disruption; Monteggia = ULNA shaft + PROXIMAL radioulnar joint (radial head dislocation); both require ORIF in adults; both have the `radiocapitellar line / DRUJ rule` that is easy to miss; mnemonic: `G = Radial Shaft + DRUJ; M = Ulna + Radial head`
• Galeazzi in children: unlike adults, children may be managed with cast immobilisation in supination if reduction is achieved; however, ANY displacement of the DRUJ with a radial shaft fracture in a child requires at least closed reduction and careful follow-up; the paediatric radius can remodel small residual deformities if growth remaining is adequate
• Volar Henry approach for radial shaft fixation: interval between brachioradialis (lateral) and flexor carpi radialis (medial); the radial artery is in the interval and must be identified and protected; the pronator teres insertion is elevated to expose the middle third of the radius; the pronator quadratus is elevated to expose the distal radius; the radial nerve (superficial branch) is protected by retracting brachioradialis laterally