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Distal radius fracture
A distal radius fracture is the most common fracture of the upper limb; the choice between cast and surgery rests on fracture stability, acceptable alignment and the patient's age and demands, and in an adult over 65 it is also a sign of osteoporosis that needs investigation.
Why it matters in the exam
Questions usually present an older woman who fell on an outstretched hand with a dinner-fork deformity of the wrist — a Colles fracture, in which the distal fragment shifts toward the back of the hand and shortens. A Smith fracture is the reverse, with displacement toward the palm, and a Barton fracture is a fracture of the joint rim with subluxation of the carpus. In a young adult such a fracture usually results from high energy and is sometimes intra-articular. Accepted criteria for alignment after reduction include radial shortening of less than 3 mm, dorsal tilt of less than 10 degrees and a joint surface step of less than 2 mm. In young and active patients, a fracture that does not meet these criteria or is unstable is usually treated with a volar plate; in adults over 65 with low demands, casting usually gives similar functional results even with less perfect alignment. Important complications: acute median nerve compression (acute carpal tunnel syndrome) that needs urgent release, late rupture of the extensor pollicis longus tendon (EPL), sometimes after an undisplaced fracture, complex regional pain syndrome (CRPS) and malunion. In children, a buckle (torus) fracture is stable and treated in a removable splint without follow-up. In an adult over 50 with a fracture from a standing-height fall, refer for osteoporosis assessment and falls risk assessment.
Key points
- Colles — dorsal displacement; Smith — volar; Barton — joint rim.
- Acceptable alignment: shortening under 3 mm, dorsal tilt under 10 degrees, step under 2 mm.
- Active patient with an unstable fracture — plate; older adult with low demands — usually cast.
- Complications: median nerve, EPL rupture, CRPS and malunion.
- Older adult with a fracture from a minor fall — osteoporosis assessment.
Summary table
| Measure | Approximate normal value | Acceptable limit after reduction |
|---|---|---|
| Radial height | About 11 mm | Shortening of less than 3 mm |
| Volar tilt | About 11 degrees toward the palm | Dorsal tilt of less than 10 degrees |
| Radial inclination | About 22 degrees | Only a moderate decrease |
| Articular step | No step | Less than 2 mm |
| Adult over 65 with low demands | — | Cast acceptable even with less perfect alignment |
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Sources
- AAOS Clinical Practice Guideline, 2020 — Management of Distal Radius Fractures
- NICE Guideline NG38, 2016 — Fractures (non-complex): assessment and management
- Rockwood and Green's Fractures in Adults, 9th ed. (2019) — Distal Radius and Ulna Fractures
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.