Distal Radius Fractures

The distal radius is the most common fracture treated by orthopaedic surgeons, over 640,000 a year in the USA, and the number is rising as the population ages.

Who. The age distribution is bimodal. Young adults fracture through high-energy trauma, sport and motor vehicle accidents; those over 50 fracture through low-energy falls onto osteoporotic bone, and the peak incidence is in women aged 60-69.

Risk factors. Osteoporosis is the major patient factor. The rest are worth knowing because the modifiable ones should be addressed to prevent the next fracture.

• Patient: female sex, previous fracture, low BMI, vitamin D deficiency
• Environmental: icy conditions, poor lighting, trip hazards, sporting activity

Mechanism. The position of the wrist at impact sets the pattern, and the pattern sets the treatment.

• Colles, the most common: a fall on the outstretched hand with the wrist in dorsiflexion, producing dorsal angulation
• Smith: a fall with the wrist in flexion, or a direct blow to the dorsum, producing volar angulation
• Barton: a shear mechanism producing a rim fracture, volar or dorsal lip, with the carpus subluxing along with the rim

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The bone. The distal radius carries two articular surfaces for the carpus, the scaphoid fossa and the lunate fossa, and a third, the sigmoid notch, for the ulnar head at the distal radioulnar joint (DRUJ). The radial styloid is its most radial projection, and Lister's tubercle is the dorsal prominence around which extensor pollicis longus (EPL) turns. Both the radiocarpal joint and the DRUJ must be addressed in treatment, because anatomic restoration of these articulations is essential for optimal function.

What lies on it. The soft tissues that matter sit on either face of the bone.

• Volar: pronator quadratus, the flexor tendons, the median nerve in the carpal tunnel and the radial artery
• Dorsal: the six extensor compartments, EPL around Lister's tubercle and the terminal branch of the posterior interosseous nerve

The TFCC. The triangular fibrocartilage complex stabilises the DRUJ and may be injured with a distal radius fracture, so its integrity is assessed whenever the DRUJ is unstable.

Radiographic anatomy. A set of measurements describes the distal radius, and displacement is described as the loss of them.

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The three common systems answer different questions. The eponyms describe the deformity, AO/OTA describes articular involvement and comminution, and Frykman counts the joints involved and the ulnar styloid.

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History. A fall on the outstretched hand (FOOSH) is the classic mechanism; ask whether the energy was high or low and whether the hand struck in extension or flexion, since that predicts the pattern. The patient reports pain and swelling, a dinner fork deformity, numbness in the median nerve distribution or weakness. Age, hand dominance, occupation and hobbies, functional demands and any history of osteoporosis strongly influence the treatment decision, so they belong in the first conversation.

Inspection and palpation. Look for the deformity, a dorsal dinner fork or a volar garden spade, the extent of swelling, ecchymosis and the integrity of the skin, because an open fracture changes the timetable. Palpate the fracture site, the carpal bones and the scaphoid especially, the DRUJ, where tenderness means injury, and the ulnar styloid.

Neurovascular examination. Test the median nerve (thenar sensation, thumb opposition), the ulnar nerve (small finger sensation, the interossei), the radial artery pulse and capillary refill. Document all of it before and after any reduction attempt.

Differential diagnosis. A painful, swollen wrist after a fall is not always a distal radius fracture, and the mimics change management.

Radiographs. A PA and a true lateral of the wrist, with oblique views if needed, are sufficient for most treatment decisions. Each view answers a different question, so measure systematically:

• Volar tilt on the lateral
• Radial inclination on the PA
• Radial length and ulnar variance on the PA
• Articular step-off
• DRUJ congruity

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CT. Order it for the complex intra-articular fracture, for die-punch assessment, for pre-operative planning of a comminuted fracture and to assess the articular fragments. It provides the fragment number and size, quantifies the articular step, identifies a central depression and shows sigmoid notch involvement, which is why it is particularly useful for surgical planning in complex cases.

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MRI is rarely needed acutely. It is the test for the TFCC, the scapholunate ligament and the occult scaphoid fracture.

Before surgery, request bone density if osteoporosis is a concern, and blood tests as the anaesthetist requires.

The decision. Three things decide it: whether the fracture is stable, whether the alignment after reduction is acceptable, and who the patient is. A stable, well-aligned fracture goes in a cast; an unstable or malaligned one is discussed for fixation; and in an older patient the millimetres count for less than the demand placed on the wrist.

Algorithm

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Acceptable alignment after reduction. These are the criteria a closed reduction must meet for cast treatment to continue:

• Volar tilt loss under 10° (slight dorsal tilt is acceptable)
• Radial shortening under 3mm
• Radial inclination loss under 5°
• No articular step over 2mm
• Congruent DRUJ

Two lists, two questions. The acceptance criteria describe the alignment after reduction. The Lafontaine factors are read on the initial radiograph and predict secondary displacement in a cast; three or more should prompt closer surveillance or a lower threshold for primary surgical fixation.

Non-operative treatment. It is the treatment for the stable, minimally displaced fracture with acceptable alignment, for the patient with low functional demand, and for the patient with a contraindication to surgery. Reduce under haematoma block, immobilise in a below-elbow cast or sugar-tong splint for 6 weeks, and take weekly radiographs for the first 2-3 weeks, because loss of reduction has to be caught early to be corrected.

When to operate. The thresholds are the acceptance criteria failed, plus the situations that are operative whatever the alignment.

By pattern. The quick decision guide, pattern by pattern.

Choosing the fixation. The volar locking plate is the gold standard for the unstable fracture, and its technique has its own section below. The alternatives each have a place:

• External fixation: reduction by ligamentotaxis; for open fractures and severe comminution; bridging (wrist-spanning) or non-spanning
• Fragment-specific fixation: multiple small plates for specific fragments, a volar ulnar corner plate, a radial column plate; useful for complex patterns
• K-wires: the Kapandji intrafocal technique, supplemental fixation, and low-demand patients; the wires must be protected

What the trials add. Gold standard does not mean only option, and the evidence cards below should shape the conversation with the patient. In DRAFFT, for fractures the surgeon judged could be held by either method, K-wires matched the volar plate on PRWE at 12 months and were cheaper. In DRAFFT2, a moulded cast after manipulation matched K-wires at one year, but 13% of the cast group needed surgery for loss of position within six weeks, which is the reason for the weekly films above. In Arora's trial of patients aged 65 or older, cast matched plate on PRWE, DASH, motion and pain at 12 months despite better alignment with plating; grip strength was better with the plate, and complications were significantly more frequent. Against external fixation for unstable fractures, QuickDASH did not differ at one year, but the plate gave a higher Mayo wrist score, better supination and less radial shortening, most of all in AO type C2/C3 patterns.

The volar locking plate through the FCR approach is the operation to be able to describe from consent to closure. The flexor carpi radialis (FCR) approach gives excellent exposure while protecting the dorsal structures.

The technical points that decide the result. Complete the reduction before plating, then use the plate itself as a reduction aid to restore volar tilt. The distal screws belong in subchondral bone and not in the joint, every fluoroscopic view is checked before closing, and the DRUJ is tested once the radius is fixed. Meticulous attention to plate position and screw length is what prevents the tendon complications.

The post-operative radiograph should confirm anatomic restoration of every parameter measured on the injury film.

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Assessing the DRUJ. Release the tourniquet before testing. Test stability in supination, neutral and pronation and compare the translation to the opposite side; increased translation indicates a TFCC injury. An unstable DRUJ may reflect a TFCC tear or an ulnar styloid base fracture and may need treatment of its own, so stability must be confirmed before leaving theatre:

• Consider ulnar styloid base fixation
• TFCC repair may be needed
• K-wire across the DRUJ, removed at 6 weeks
• Immobilise in supination if stable after pinning

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Acute carpal tunnel syndrome. Swelling or haematoma compresses the median nerve, and it may occur at presentation or after reduction. Median nerve symptoms in a swollen, severely painful wrist need urgent attention: release the carpal tunnel if the symptoms are progressive, and consider emergent release at the time of fracture fixation.

Compartment syndrome. The forearm compartments are at risk, so monitor closely after the injury and perform fasciotomy if it is diagnosed.

Loss of reduction. Common in unstable patterns, which is why the weekly radiographs matter; a fracture that redisplaces may need operative stabilisation.

Malunion. Dorsal tilt and shortening are the common residuals and they limit function; a symptomatic malunion may need a corrective osteotomy.

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EPL rupture. It presents 2-6 weeks after the injury, from irritation of the tendon at Lister's tubercle. Dorsal screw prominence causes the same irritation, so avoid prominent dorsal hardware. Treatment is an EIP-to-EPL tendon transfer.

Post-traumatic arthritis. It follows articular incongruity and is more likely with a step over 2mm; it may need wrist fusion or arthroplasty late.

CRPS. Complex regional pain syndrome presents as burning pain, swelling and colour change. Early therapy is crucial for prevention, and patient education and early mobilisation help prevent the late complications generally.

Post-traumatic stiffness. Range of motion is lost at the fingers as well as at the wrist.

Hardware. Prominent hardware damages tendons: on the volar side the flexor tendons, rarely; on the dorsal side EPL is most at risk. Intra-articular screws must be excluded on intra-operative fluoroscopy and removed and revised if present, because left alone they cause arthritis. Hardware failure is rare with modern locking plates, which have significantly reduced hardware-related complications, more common in osteoporotic bone, and may call for augmentation techniques. Modern implants have significantly reduced hardware-related complications.

The aim after a locked plate is to move early under protection. Fingers move at once; the wrist starts at 2 weeks; grip strengthening begins at 4 weeks; full range is expected by 8-12 weeks.

Most patients achieve excellent functional outcomes with structured rehabilitation, and early finger movement is what prevents stiffness.

Union is the rule with either treatment; what separates them is how reliably alignment is held and what the complications look like.

What predicts the result. The favourable fracture is extra-articular and stable, anatomically reduced, in a young patient with good bone who complies with therapy. The unfavourable one has intra-articular comminution or an articular step over 2mm, osteoporotic bone, a malunion or an associated DRUJ injury.

Global Epidemiology

The distal radius is among the most commonly fractured bones worldwide, with a bimodal age distribution: a peak in children and adolescents from sport and play, and a second osteoporotic peak in older adults (predominantly women). Population data over the past 40 years show a rising prevalence in both the paediatric and elderly groups, driven by ageing populations and activity patterns. [Nellans, Hand Clin 2012, PMID 22554654]

Major Guidelines Side by Side

Registry & Trial Evidence

Practice Variation

Management genuinely differs by region and resource setting. In high-resource systems, volar locking plate use has risen steeply over two decades despite trial data showing no consistent functional advantage over cast or K-wires in older patients. In limited-resource settings, closed reduction and casting or K-wire fixation remain mainstays because they are effective and low cost. Day-case surgery and wide-awake local anaesthetic no tourniquet (WALANT) technique are expanding internationally as cost-conscious options. The recurring exam message is that radiographic restoration does not equal functional benefit in the low-demand elderly.