Forearm Fractures
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Direct answer
Forearm fractures matter because the radius and ulna form a joint-like unit that rotates around each other, so both-bone fractures in adults behave like intra-articular injuries and are almost always treated by open reduction and internal fixation with plates. Two eponymous patterns pair a single broken bone with a dislocated joint at the other end — Monteggia (ulna shaft with radial head dislocation) and Galeazzi (radial shaft with distal radio-ulnar disruption) — and both are missed when the second joint is not imaged.
What you must remember
- Both-bone fractures in adults need anatomical open reduction and plating of both bones, because even small angulation erodes the interosseous space and costs pronation-supination; conservative treatment is the exception, not the rule.
- Monteggia fracture-dislocation: fracture of the proximal ulna with dislocation of the radial head; Bado type I — anterior dislocation — is the commonest; the posterior interosseous nerve is at risk and its palsy may present as drop fingers without wrist drop, since the extensor carpi radialis is spared.
- Galeazzi fracture-dislocation: fracture of the radial shaft, classically at the junction of the middle and distal thirds, with disruption of the distal radio-ulnar joint; famously the "fracture of necessity" because it needs operative fixation.
- Isolated ulna shaft (nightstick) fracture: from a direct blow, treated conservatively in a cast or brace if undisplaced.
- Radial shaft level decides fragment posture: above the supinator insertion the proximal fragment supinates; below pronator teres the supinators and pronators partly balance, which is why level determines the reduction position.
- In children, plastic deformation, greenstick and complete fractures dominate, and remodelling allows conservative management of many angulated fractures that would be plated in adults.
- Essex-Lopresti injury: radial head fracture with distal radio-ulnar disruption and interosseous membrane damage — the proximal cousin of Galeazzi.
Common confusion
The eponymes are swapped in a hurry, so anchor them anatomically: Monteggia breaks the ulna and dislocates proximally at the elbow; Galeazzi breaks the radius and disrupts the wrist-side distal radio-ulnar joint. A simple frame — Monteggia: ulna, elbow; Galeazzi: radius, wrist — prevents most errors. The second trap is satisfaction of search: an apparently isolated forearm fracture demands films of the elbow and wrist, or the dislocated radial head or distal radio-ulnar joint is missed until stiffness sets in.
Exam-focused takeaway
NEET-PG leans on recognition vignettes: a proximal ulna fracture asks for elbow films to catch Monteggia's dislocated radial head, and wrist pain with a radial shaft fracture points to Galeazzi. Nerve stems test the posterior interosseous nerve of Monteggia as a motor-only palsy — wrist extension preserved, fingers dropped, no sensory loss. Management answers pair adult both-bone and Galeazzi fractures with open plating and children's greenstick fractures with closed reduction, with one-liners on the nightstick fracture and the Essex-Lopresti combination.
Frequently asked questions
What is a Monteggia fracture-dislocation?
A fracture of the proximal ulna with dislocation of the radial head, commonest in Bado type I with anterior dislocation, complicated by posterior interosseous nerve palsy.
What is a Galeazzi fracture-dislocation?
A fracture of the radial shaft at the junction of its middle and distal thirds with disruption of the distal radio-ulnar joint, treated by open reduction and plating.
Why must adult both-bone forearm fractures be fixed operatively?
The forearm rotates as a unit, so residual angulation narrows the interosseous space and permanently restricts pronation and supination.
Which nerve is at risk in a Monteggia injury?
The posterior interosseous nerve, causing finger and thumb extension weakness without sensory loss, often recovering after reduction.
What is a nightstick fracture?
An isolated, usually undisplaced fracture of the ulna shaft from a direct blow, generally managed conservatively.