Smith's Fracture
Smith's fracture is a distal radius fracture characterised by volar (palmar) displacement and angulation of the distal f... FRCS exam preparation.
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Urgent signals
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- Acute carpal tunnel syndrome (median nerve compression)
- Vascular compromise (absent radial pulse)
- Open fracture
- Compartment syndrome of forearm
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Linked comparisons
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- Colles Fracture
- Barton Fracture
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Reviewed by MedVellum Editorial Team · MedVellum Medical Education Platform
Credentials: MBBS, MRCP, Board Certified
Smith's Fracture
1. Topic Overview
Summary
Smith's fracture is a distal radius fracture characterised by volar (palmar) displacement and angulation of the distal fragment — mechanistically and radiographically the opposite of the more common Colles' fracture. First described by Robert William Smith in Dublin in 1847, these fractures represent approximately 3-5% of all distal radius fractures. [1] The injury typically results from a fall onto a flexed wrist (reverse FOOSH mechanism) or a direct blow to the dorsum of the forearm, distinguishing it from the classic Colles' fracture which occurs with wrist extension.
Smith's fractures are inherently unstable due to the volar displacement combined with the deforming forces of the wrist flexor muscles. [2] The flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), and finger flexor tendons all exert a volarly-directed force on the distal fragment, making closed reduction difficult to maintain. Conservative management with casting has historically demonstrated high failure rates of 30-50%, with frequent loss of reduction. [3] Consequently, operative fixation with a volar locking plate has become the gold standard treatment for displaced Smith's fractures in adults, providing stable fixation that permits early mobilisation and excellent functional outcomes. [4]
A critical clinical concern is acute carpal tunnel syndrome, which occurs in 5-15% of Smith's fractures due to the volar displacement directly compressing the median nerve within the carpal tunnel. [5] This represents an orthopaedic emergency requiring urgent decompression. Recognition of the volar displacement pattern on lateral radiographs and understanding that surgical fixation is typically required leads to optimal patient outcomes.
Key Facts
| Feature | Detail |
|---|---|
| Eponym | Robert William Smith (Dublin, 1847) |
| Definition | Distal radius fracture with volar angulation/displacement |
| Mechanism | Fall onto flexed wrist OR direct dorsal blow |
| Key Radiographic Sign | Volar tilt of distal fragment on lateral view (vs. dorsal in Colles') |
| Frequency | 3-5% of distal radius fractures [1] |
| Stability | Inherently unstable — high redisplacement rate with cast alone |
| Treatment | Volar locking plate ORIF is gold standard for displaced fractures [4] |
| Critical Complication | Acute carpal tunnel syndrome (5-15%) [5] |
Clinical Pearls
"Garden Spade" vs "Dinner Fork": Smith's fracture creates a "garden spade" deformity with volar prominence of the wrist, while Colles' fracture creates the classic "dinner fork" deformity with dorsal displacement. Always examine the wrist from the lateral aspect to distinguish these patterns.
Median Nerve Alert: Acute carpal tunnel syndrome occurs more frequently with Smith's fractures than Colles' fractures due to the volar displacement directly impinging on the carpal tunnel. Always document median nerve function pre- and post-reduction. Persistent or worsening symptoms mandate urgent surgical decompression.
Casts Fail Frequently: Unlike Colles' fractures where casting remains a viable option for stable fractures, Smith's fractures are notoriously difficult to maintain in reduction with cast immobilisation alone. The volar displacement combined with flexor muscle forces makes conservative management unreliable. [3]
Volar Plate Advantage: The modified Henry approach for volar locking plate placement allows direct visualisation of the articular surface, anatomic reduction, and stable fixation permitting early mobilisation — all contributing to superior functional outcomes compared to conservative management. [6]
Why This Matters Clinically
Smith's fractures, though less common than Colles' fractures, have fundamentally different biomechanics and management implications. Their inherent instability means that attempted conservative treatment often fails, leading to malunion with persistent volar tilt. This affects wrist biomechanics, reduces grip strength, and may cause chronic pain. Recognition of the volar displacement pattern on the lateral radiograph, prompt identification of median nerve compression, and understanding that surgical fixation is typically indicated are essential for optimal patient outcomes.
2. Epidemiology
Incidence & Prevalence
Smith's fractures account for approximately 3-5% of all distal radius fractures, making them significantly less common than Colles' fractures which represent 85-90% of distal radius fractures. [1,7] The overall incidence of distal radius fractures is approximately 195-258 per 100,000 person-years, with Smith's fractures therefore occurring at approximately 6-13 per 100,000 person-years. [8]
| Statistic | Value | Source |
|---|---|---|
| Proportion of DRF | 3-5% | [1] |
| Estimated incidence | 6-13 per 100,000/year | [8] |
| Age distribution | Bimodal | [7] |
| Male:Female ratio | Variable by age | [9] |
Demographics
The age distribution of Smith's fractures is bimodal, reflecting two distinct patient populations with different injury mechanisms:
Young Adults (20-40 years)
- Predominantly male
- High-energy trauma mechanism
- Motorcycle/bicycle handlebar injuries common
- Sports-related injuries
- Often involves dominant hand
- Typically good bone quality
Elderly Adults (> 60 years)
- Female predominance (osteoporotic population)
- Low-energy falls
- Fall onto flexed wrist
- Often involves non-dominant hand (protective reflex)
- Osteoporotic bone contributes to fracture pattern
- Higher complication rates
| Factor | Young Adults | Elderly Adults |
|---|---|---|
| Age | 20-40 years | > 60 years |
| Sex | Male predominant | Female predominant |
| Mechanism | High-energy trauma | Low-energy falls |
| Bone quality | Normal | Often osteoporotic |
| Hand affected | Dominant | Non-dominant |
| Associated injuries | Common | Less common |
Risk Factors
Non-Modifiable Risk Factors
- Previous wrist fracture (2-4x increased risk)
- Advanced age (> 60 years)
- Female sex in osteoporotic age group
- Caucasian ethnicity
- Family history of osteoporotic fractures
- Early menopause
Modifiable Risk Factors
| Risk Factor | Relative Risk | Notes |
|---|---|---|
| Osteoporosis | 3-4x | Major contributor in elderly; DEXA screening recommended post-fracture [10] |
| Vitamin D deficiency | 1.5-2x | Common in elderly population |
| Low physical activity | 1.5x | Reduced bone density, impaired balance |
| Smoking | 1.5x | Delayed union, increased complication risk |
| Excessive alcohol | 1.5-2x | Falls risk, bone quality |
| Motorcycle/bicycle riding | High | Handlebar impact mechanism |
| Contact sports | Moderate | Direct blow mechanism |
Geographic and Temporal Trends
Distal radius fracture incidence shows seasonal variation, with increased rates in winter months in temperate climates due to icy conditions. [11] The proportion of Smith's fractures relative to other distal radius fracture patterns has remained relatively stable over time, though the overall treatment approach has shifted substantially toward operative management with the advent of volar locking plate technology in the early 2000s. [4]
3. Anatomy
Relevant Surgical Anatomy
Understanding the anatomy of the distal radius is essential for both comprehending the fracture pattern and performing safe surgical fixation.
Distal Radius Osteology
The distal radius has a complex three-dimensional shape that articulates with both the carpus and the ulna:
| Surface | Key Features |
|---|---|
| Articular surface | Biconcave for scaphoid and lunate facets; 15-25° volar tilt (sagittal), 15-25° radial inclination (coronal) |
| Volar surface | Watershed line defines distal extent of volar cortex; pronator quadratus origin |
| Dorsal surface | Lister's tubercle; extensor compartments |
| Radial styloid | Point of attachment for brachioradialis; origin of radial collateral ligament |
| Sigmoid notch | Articulates with ulnar head at DRUJ |
Normal Radiographic Parameters
| Parameter | Normal Range | Clinical Significance |
|---|---|---|
| Radial inclination | 15-25° (mean 23°) | Measured on PA view |
| Radial height | 9-13 mm (mean 11 mm) | Ulnar variance |
| Volar tilt | 0-22° (mean 11°) | Key parameter in Smith's — becomes negative (dorsal) |
| Ulnar variance | -2 to +2 mm | Neutral is most common |
| Articular step-off | less than 2 mm acceptable | Influences arthritis risk |
Volar Soft Tissue Structures
The volar wrist contains critical structures that influence both fracture displacement and surgical approach:
- Pronator quadratus: Muscle overlying volar distal radius; elevated during surgical approach
- Flexor carpi radialis (FCR) tendon: Key landmark for Henry approach; lies radial to median nerve
- Median nerve: Enters carpal tunnel through Guyon's canal; at risk with volar displacement
- Flexor tendons: Pass through carpal tunnel; can be irritated by prominent hardware
- Radial artery: Lies radial to FCR; protected during approach
- Palmar cutaneous branch of median nerve: At risk during volar approach; travels in fascia between FCR and palmaris longus
Watershed Line Concept
The watershed line is a critical anatomical concept for volar plate positioning. [12] It represents the most volar prominence of the distal radius articular margin and defines the safe zone for plate placement. Plates positioned distal to this line risk flexor tendon irritation and rupture, particularly of the FPL tendon.
Carpal Tunnel Anatomy
The carpal tunnel is bounded:
- Roof: Transverse carpal ligament (flexor retinaculum)
- Floor and walls: Carpal bones
- Contents: Median nerve, 4 FDP tendons, 4 FDS tendons, FPL tendon
In Smith's fracture, volar displacement of the distal radius fragment directly narrows the carpal tunnel, predisposing to acute carpal tunnel syndrome. This is the primary mechanism for median nerve symptoms in this injury pattern. [5]
DRUJ Anatomy
The distal radioulnar joint (DRUJ) must be assessed in all distal radius fractures:
- Articulation: Sigmoid notch of radius with ulnar head
- Stabilisers: TFCC (primary), volar and dorsal radioulnar ligaments, pronator quadratus, ECU subsheath
- Clinical relevance: May be disrupted in Smith's fractures, especially with high-energy mechanism or significant displacement
4. Pathophysiology
Mechanism of Injury
Smith's fractures occur through two primary mechanisms, both of which result in volarly-directed force transmission through the distal radius:
Mechanism 1: Fall on Flexed Wrist (FOFOW - "Reverse FOOSH")
This is the most common mechanism for Smith's fracture, mechanistically opposite to the Colles' fracture:
- Patient falls with wrist in palmar flexion
- Impact occurs on the dorsum of the hand
- Axial load is applied with wrist flexed
- Force vector drives distal radius fragment volarly
- Result: Volar displacement with apex dorsal angulation
This mechanism is seen in:
- Falls while grasping objects
- Falls with clenched fist
- Falls from stairs with hand grasping rail
- Athletic injuries with wrist flexed at impact
Mechanism 2: Direct Dorsal Blow
A direct impact to the dorsal aspect of the forearm transmits force volarly:
- Direct impact to dorsum of distal forearm
- Force pushes distal fragment volarly relative to shaft
- May occur with or without axial loading
- Result: Volar displacement pattern
This mechanism is seen in:
- Motorcycle handlebar impacts
- Bicycle accidents
- Industrial injuries
- Assault with direct blow
Thomas Classification
The Thomas classification (1957) remains the standard for categorising Smith's fractures based on the fracture pattern: [13]
| Type | Pattern | Features | Stability |
|---|---|---|---|
| Type I | Extra-articular transverse | Transverse fracture line through metaphysis; volar angulation; no articular involvement | Unstable |
| Type II | Intra-articular (Volar Barton's) | Oblique fracture line involving volar lip of distal radius; carpal subluxation common | Very unstable |
| Type III | Oblique extra-articular | Juxta-articular oblique fracture; more distal than Type I; volar displacement | Unstable |
Exam Detail: Type I (Classic Smith's)
- Most common type (approximately 60-70%)
- Transverse fracture through distal radius metaphysis
- Volar angulation of distal fragment
- Extra-articular — joint surface intact
- Mechanism: Fall onto flexed wrist (low energy) or direct blow
Type II (Volar Barton's Variant)
- Intra-articular fracture
- Oblique fracture line extends into volar lip of radiocarpal joint
- Volar shear pattern
- Often associated with volar subluxation of carpus
- Most unstable type — requires operative fixation
- Higher risk of post-traumatic arthritis
Type III (Juxta-articular)
- Oblique fracture pattern
- More distal location than Type I
- Extra-articular but close to joint
- May propagate into joint with repeated manipulation
Fracture Instability
All Smith's fractures are considered inherently unstable due to multiple factors: [2,3]
Anatomical Factors
- Volar cortex is thinner and weaker than dorsal cortex
- Once fractured, no bony buttress prevents further displacement
- Volar periosteum disrupted
Muscular Forces
- FCR, FCU, and finger flexors all insert distal to fracture
- These muscles pull the distal fragment volarly
- Supination moment further destabilises the fracture
- Continuous deforming force during healing
Ligamentous Factors
- Volar carpal ligaments may remain attached to distal fragment
- Carpal mass follows distal fragment into volar displacement
- Creates "carpal subluxation" effect in Type II fractures
Instability Criteria
The following features predict failure of conservative management: [14]
| Factor | Instability Threshold |
|---|---|
| Initial displacement | > 50% of metaphyseal width |
| Volar tilt | Any volar angulation (> 0°) |
| Radial shortening | > 5 mm |
| Intra-articular step | > 2 mm |
| Age | > 60 years (osteoporotic bone) |
| Comminution | Dorsal or volar metaphyseal comminution |
| Associated DRUJ injury | Clinical instability |
5. Clinical Presentation
History
Mechanism A detailed history of the injury mechanism helps distinguish Smith's from Colles' fracture:
| Question | Expected Response |
|---|---|
| "How did you fall?" | "Fell forward with hand tucked under" OR "Direct blow to back of wrist" |
| "What position was your wrist in?" | "Bent forward/down" (palmar flexion) |
| "Where did you land?" | "On the back of my hand" |
| "What force was involved?" | Variable — from simple fall to motorcycle accident |
Symptoms
| Symptom | Frequency | Notes |
|---|---|---|
| Wrist pain | 100% | Immediate onset |
| Swelling | 95% | Rapid development |
| Deformity | 70-80% | Volar prominence visible |
| Inability to grip | 90% | Pain and mechanical |
| Numbness/tingling | 15-20% | Median nerve distribution — RED FLAG |
| Finger weakness | 5-10% | Thenar involvement suggests acute CTS |
Atypical Presentations
- Minimal displacement initially — may be mistaken for "sprain"
- Elderly with osteoporosis — may report minimal trauma
- Delayed presentation — attempted self-management
- Associated injuries in polytrauma — may be missed
Physical Examination
General Inspection
- Expose entire forearm and hand
- Compare to contralateral side
- Note position of comfort (usually guarded in mild flexion)
- Assess for open wounds (open fracture)
Specific Findings
| Sign | Description | Frequency |
|---|---|---|
| Garden spade deformity | Volar prominence of distal wrist | 70-80% |
| Swelling | Generalised wrist swelling | 95% |
| Ecchymosis | May be delayed (12-24 hours) | 60% |
| Tenderness | Maximum over distal radius | 100% |
| Crepitus | DO NOT actively elicit | — |
| Reduced ROM | Pain-limited movement | 100% |
Neurovascular Assessment (MANDATORY)
| Structure | Assessment | Normal Finding | Abnormal Finding |
|---|---|---|---|
| Radial pulse | Palpate at wrist and anatomical snuffbox | Present, full | Absent or diminished |
| Capillary refill | Nail beds of all fingers | less than 2 seconds | Delayed or absent |
| Median nerve motor | Thumb abduction (APB), opposition | Full power | Weakness (acute CTS) |
| Median nerve sensory | Light touch thumb, index, middle fingers, radial ring finger | Normal | Numbness/paraesthesia |
| Ulnar nerve motor | Finger abduction (interossei) | Full power | Weakness |
| Ulnar nerve sensory | Ulnar 1.5 fingers | Normal | Numbness |
| Radial nerve sensory | Dorsal first web space | Normal | Numbness |
DRUJ Assessment
- Piano key test: Stabilise radius, depress ulnar head
- Compare to contralateral side
- Pain or excessive movement suggests DRUJ injury
Red Flags
[!CAUTION] Red Flags Requiring Urgent Action:
Neurological
- Numbness in median nerve distribution (thumb, index, middle fingers)
- Weakness of thumb abduction/opposition
- Progressive paraesthesia
- Two-point discrimination > 6mm
Vascular
- Absent or weak radial pulse
- Delayed capillary refill (> 2 seconds)
- Pale, cool fingers
- Pain on passive finger extension
Soft Tissue
- Open wound communicating with fracture
- Tense forearm compartments
- Pain out of proportion to injury
- Pain on passive finger extension (compartment syndrome)
Fracture
- Gross instability with subluxation
- Severe deformity with skin tenting
6. Differential Diagnosis
Primary Differentials
| Differential | Key Distinguishing Features | Investigations |
|---|---|---|
| Colles' fracture | Dorsal displacement ("dinner fork" deformity); fall on extended wrist | Lateral X-ray: dorsal tilt |
| Barton's fracture | Intra-articular rim fracture; may be volar (similar to Smith II) or dorsal | X-ray: marginal rim fracture with carpal subluxation |
| Chauffeur's fracture | Radial styloid fracture; direct blow to radial side | X-ray: isolated styloid fracture |
| Die-punch fracture | Central depression of lunate facet | CT: articular depression |
| Scaphoid fracture | Anatomical snuffbox tenderness; may coexist | Scaphoid views, MRI/CT if X-ray negative |
| Distal radial contusion | No fracture on imaging; soft tissue injury | X-ray negative; clinical diagnosis |
| DRUJ injury isolated | Isolated DRUJ pain; radius intact | DRUJ-specific views; may need MRI for TFCC |
Distinguishing Smith's from Colles' Fracture
| Feature | Smith's Fracture | Colles' Fracture |
|---|---|---|
| Deformity | Garden spade (volar) | Dinner fork (dorsal) |
| Mechanism | Fall on flexed wrist | Fall on extended wrist |
| Displacement | Volar | Dorsal |
| Angulation | Volar (apex dorsal) | Dorsal (apex volar) |
| Lateral X-ray | Volar tilt increased/positive | Dorsal tilt (negative volar tilt) |
| Stability | Inherently unstable | Variable |
| Management | Usually surgical | May be conservative if stable |
| CTS risk | Higher (5-15%) | Lower (2-5%) |
Must Not Miss
- Open fracture: Look carefully for small wounds — may be puncture from bone spike
- Acute carpal tunnel syndrome: Document median nerve status pre- and post-intervention
- Vascular injury: Rare but requires immediate intervention
- Associated carpal injuries: Scaphoid, scapholunate ligament
7. Investigations
Bedside Assessment
Mandatory Initial Assessment
- Complete neurovascular examination (document pre-intervention)
- Skin integrity assessment
- Compartment assessment (forearm tenderness, pain on passive stretch)
- Assessment for associated injuries
Imaging
First-Line Imaging
| Modality | Views | Key Findings |
|---|---|---|
| Plain Radiograph | PA and lateral wrist | First-line for all suspected fractures |
Radiographic Analysis (Lateral View — Most Important)
The lateral radiograph is critical for distinguishing Smith's from Colles' fracture:
| Measurement | Normal | Smith's Fracture |
|---|---|---|
| Volar tilt | 11° (0-22°) | Increased positive value or may show volar angulation of fragment |
| Fragment position | N/A | Volar displacement relative to shaft |
| Carpal alignment | Collinear with radius | May show volar subluxation (Type II) |
Radiographic Analysis (PA View)
| Measurement | Normal | Fracture Finding |
|---|---|---|
| Radial inclination | 23° (15-25°) | May be decreased |
| Radial height | 11 mm (9-13 mm) | May be shortened |
| Ulnar variance | Neutral (-2 to +2 mm) | Positive (radial shortening) |
| Articular surface | Smooth | Step-off or gap (if intra-articular) |
Second-Line Imaging
| Modality | Indication | Key Findings |
|---|---|---|
| CT scan | Intra-articular extension, pre-operative planning, comminution assessment | Articular step, fragment size, comminution pattern [15] |
| MRI | Suspected ligamentous injury (SL, TFCC), persistent post-treatment pain | Ligament integrity, TFCC tears, occult fractures |
Laboratory Tests
Routine laboratory investigations are not required for diagnosis but may be indicated in specific circumstances:
| Indication | Tests |
|---|---|
| Pre-operative assessment | FBC, U&E, coagulation if on anticoagulants |
| Elderly with low-energy fracture | Consider bone profile (Ca, PO4, ALP, Vitamin D), DEXA referral [10] |
| Suspected pathological fracture | FBC, ESR, CRP, bone profile, protein electrophoresis, PSA (males) |
Diagnostic Criteria
Smith's fracture is diagnosed when ALL of the following are present:
- Clinical history consistent with mechanism (fall on flexed wrist or direct dorsal blow)
- Physical examination showing volar wrist prominence
- Lateral radiograph demonstrating volar displacement/angulation of distal radius fragment
8. Management
Overview of Management Strategy
Smith's fractures differ from Colles' fractures in their inherent instability. The management algorithm therefore prioritises early identification of fracture pattern, assessment for complications (particularly median nerve compression), and recognition that most displaced fractures require operative fixation.
Emergency Department Management
Initial Assessment and Stabilisation
- Analgesia: IV morphine/fentanyl for adequate pain control
- Neurovascular documentation: Formal documentation BEFORE any manipulation
- Radiographs: PA and lateral wrist
- Temporary immobilisation: Backslab in neutral position
- Elevation: Reduce swelling
- Ice: Wrapped application for 20 minutes
Closed Reduction (If Indicated)
Closed reduction may be attempted in the ED for significantly displaced fractures, primarily to:
- Relieve median nerve compression
- Reduce skin tension
- Provide temporary stabilisation pending definitive management
Reduction Technique for Smith's Fracture
- Adequate analgesia (haematoma block, Bier's block, or procedural sedation)
- Apply traction in the line of the forearm
- Supinate the forearm (opposite to Colles' where you pronate)
- Extend the wrist (opposite to Colles' where you flex)
- Apply dorsal pressure to the distal fragment
- Maintain position and apply above-elbow backslab with forearm supinated, wrist in slight extension
Post-Reduction Care
- Repeat neurovascular examination
- Check radiographs to assess reduction
- Elevation
- Clear analgesia instructions
- Urgent orthopaedic review
Conservative Management
Indications (Limited)
Conservative management is appropriate ONLY for:
- Truly minimally displaced fractures (rare)
- Patients unfit for surgery (significant comorbidities)
- Patient preference after informed discussion of high failure rate
Technique
| Component | Detail |
|---|---|
| Cast type | Above-elbow cast (AEC) essential — controls rotation |
| Forearm position | Supination (reduces flexor muscle pull) |
| Wrist position | Slight extension (10-20°) |
| Elbow position | 90° flexion |
| Duration | 6 weeks total |
| Transition | May convert to below-elbow at 3 weeks if stable |
Monitoring (CRITICAL)
| Timepoint | Action |
|---|---|
| 1 week | X-ray to check maintenance of reduction |
| 2 weeks | X-ray to check maintenance of reduction |
| 3 weeks | X-ray — decision on transition to BEC or conversion to surgery |
| 6 weeks | Clinical and radiographic review; commence rehabilitation |
[!WARNING] High Failure Rate: Conservative management of Smith's fractures has a 30-50% rate of loss of reduction requiring conversion to surgery. [3] Weekly radiographic follow-up is mandatory for the first 3 weeks.
Surgical Management
Indications (Most Smith's Fractures)
| Indication | Notes |
|---|---|
| Displaced Smith's fracture | Any significant displacement |
| Intra-articular involvement | Type II (volar Barton) — always surgical |
| Failed closed reduction | Unable to achieve or maintain reduction |
| Median nerve symptoms | Requires decompression |
| Unstable fracture pattern | Comminution, shortening > 5mm |
| Open fracture | Requires debridement and fixation |
| Polytrauma patient | Early fixation facilitates mobilisation |
Timing
| Scenario | Timing |
|---|---|
| Open fracture | Emergency (within 24 hours) |
| Acute CTS | Urgent (within 24-48 hours) |
| Closed displaced fracture | Semi-elective (within 2 weeks, ideally within 7 days) |
| Delayed presentation | After swelling subsides (soft tissue permitting) |
Surgical Techniques
Volar Locking Plate ORIF (Gold Standard) [4,6]
This is the standard operative treatment for Smith's fractures in adults.
| Aspect | Detail |
|---|---|
| Approach | Modified Henry (FCR) approach |
| Incision | Longitudinal, centred on FCR tendon, extending from wrist crease proximally |
| Interval | Between FCR and radial artery (artery retracted radially) |
| Key steps | Release pronator quadratus, reduce fracture, apply volar locking plate |
| Plate position | Distal to watershed line (avoid FPL irritation) [12] |
| Fixation | Locking screws into subchondral bone distally |
| Closure | Repair pronator quadratus if possible; routine skin closure |
Exam Detail: Surgical Steps for Volar Plate Fixation
- Positioning: Supine, arm on hand table, tourniquet applied
- Incision: FCR approach, 6-8 cm longitudinal incision
- Superficial dissection: Incise FCR sheath, retract FCR ulnarly
- Deep dissection: Incise fascia between FCR and radial artery
- Protect structures: Radial artery (radial), median nerve (ulnar)
- Pronator quadratus: Incise radially, elevate as L-shaped flap
- Fracture exposure: Visualise volar cortex and fracture site
- Reduction: Traction, manipulation, restoration of volar tilt and radial length
- Provisional fixation: K-wires if needed
- Plate application: Contoured volar locking plate, position proximal to watershed line
- Fixation sequence: Proximal cortical screw first (gliding hole), then distal locking screws
- Check reduction: Fluoroscopy — PA, lateral, and oblique views
- Articular screws: Confirm subchondral position, not penetrating dorsal cortex
- Closure: Repair pronator quadratus, skin closure
Intraoperative Fluoroscopy Checks
| View | Assessment |
|---|---|
| PA | Radial inclination, radial height, screw length |
| Lateral | Volar tilt, plate position (not distal to watershed line), screw length |
| Oblique (20° tilt) | Screw penetration of dorsal cortex |
Alternative Fixation Methods
| Method | Indication | Notes |
|---|---|---|
| External fixation | Open fractures, severe soft tissue injury, polytrauma | Allows staged approach; may be converted to ORIF |
| Fragment-specific fixation | Complex articular patterns | Combination of plates/screws for individual fragments |
| Dorsal plating | Rarely used for Smith's | Historically used; higher complication rate |
| K-wire fixation | Rarely appropriate | Insufficient stability for Smith's pattern |
Carpal Tunnel Release
| Indication | Technique |
|---|---|
| Acute CTS symptoms | Extend volar incision distally, release transverse carpal ligament |
| Pre-operative CTS | Can be performed through same approach |
| Prophylactic | Controversial; consider with marked displacement or ongoing symptoms post-reduction |
DRUJ Assessment and Management
| Timing | Assessment |
|---|---|
| After fracture fixation | Test DRUJ stability with forearm in supination, neutral, and pronation |
| If stable | No additional intervention |
| If unstable | K-wire stabilisation in supination, consider TFCC repair if indicated |
Post-operative Care
Immediate Post-operative
| Component | Detail |
|---|---|
| Splint | Removable wrist splint OR no splint (surgeon preference) |
| Elevation | Above heart level for 48-72 hours |
| Analgesia | Multimodal (paracetamol, NSAID if not contraindicated, opioids PRN) |
| Wound care | Keep dry until suture removal |
| Mobilisation | Finger range of motion exercises immediately |
Rehabilitation Protocol
| Phase | Timing | Goals | Exercises |
|---|---|---|---|
| Phase 1 | 0-2 weeks | Oedema control, finger ROM | Finger exercises, elevation, ice |
| Phase 2 | 2-6 weeks | Wrist ROM, scar management | Active wrist flexion/extension, pronation/supination, grip exercises |
| Phase 3 | 6-12 weeks | Strengthening | Progressive resistance exercises, functional activities |
| Phase 4 | > 12 weeks | Return to full activity | Sport-specific/occupational rehabilitation |
Follow-up Schedule
| Timepoint | Assessment |
|---|---|
| 2 weeks | Wound check, suture removal, radiographs, hand therapy |
| 6 weeks | Clinical review, radiographs, assess union |
| 12 weeks | Final review if progressing well; radiographs if concerns |
Special Populations
Elderly Patients (> 65 years)
| Consideration | Management |
|---|---|
| Osteoporosis | DEXA scan referral; bone health optimisation [10] |
| Frailty | Balance higher surgical risks against benefits of stable fixation |
| Cognitive impairment | Consider compliance with rehabilitation |
| Falls risk | Falls prevention programme referral |
| Plate position | May need longer plate for osteoporotic bone |
High-Demand Patients (Athletes, Manual Workers)
| Consideration | Management |
|---|---|
| Return to sport/work | Typically 8-12 weeks for non-contact; 12-16 weeks for contact sports |
| Expectations | Counsel regarding recovery timeline |
| Rehabilitation | Intensive physiotherapy programme |
| Hardware removal | May be required for contact athletes (rare) |
9. Complications
Immediate Complications (Hours-Days)
| Complication | Incidence | Presentation | Management |
|---|---|---|---|
| Acute carpal tunnel syndrome | 5-15% [5] | Numbness, weakness of thenar muscles | Urgent carpal tunnel release |
| Vascular injury | less than 1% | Absent pulse, cool digits | Urgent vascular assessment, possible exploration |
| Compartment syndrome | less than 1% | Pain on passive stretch, tense forearm | Emergency fasciotomy |
| Loss of reduction (cast) | 30-50% [3] | Displacement on follow-up X-ray | Convert to surgical fixation |
Early Complications (Weeks)
| Complication | Incidence | Presentation | Management |
|---|---|---|---|
| Wound infection | 2-4% | Erythema, discharge, wound dehiscence | Antibiotics, debridement if deep |
| Superficial radial nerve injury | 2-5% | Numbness dorsal thumb/index | Usually neurapraxia; observation |
| Tendon irritation | 5-10% | Pain on gripping, finger movement | May require hardware removal |
| Hardware issues | 2-5% | Prominent screws, tendon irritation | Revision if symptomatic |
Late Complications (Months-Years)
| Complication | Incidence | Presentation | Management |
|---|---|---|---|
| Flexor tendon rupture | 2-5% [16] | Sudden loss of finger flexion, particularly FPL | Tendon reconstruction; avoid with proper plate positioning |
| Malunion | 5-10% (surgical) | Reduced grip strength, pain, stiffness | Corrective osteotomy if symptomatic |
| Post-traumatic arthritis | 10-15% (intra-articular) | Pain, stiffness, reduced ROM | Analgesia, arthrodesis if severe |
| DRUJ instability | 5-10% | Pain on rotation, clicking | TFCC repair, DRUJ reconstruction |
| Complex regional pain syndrome | 5-10% | Disproportionate pain, swelling, colour/temperature changes | Early recognition, MDT management |
| Carpal tunnel syndrome (late) | 5-10% | Progressive numbness, thenar weakness | Carpal tunnel release |
| Stiffness | 10-20% | Reduced ROM | Physiotherapy; rarely manipulation under anaesthesia |
Flexor Pollicis Longus Rupture
FPL rupture is a specific complication of volar plate fixation that deserves particular attention: [16]
Risk Factors
- Plate positioned distal to watershed line
- Prominent distal screws
- Inadequate pronator quadratus repair
- Malpositioned plate
Prevention
- Careful plate positioning (proximal to watershed line)
- Confirm screw length on lateral fluoroscopy
- Consider low-profile plates
- Repair pronator quadratus when possible
Management
- Hardware removal
- Tendon reconstruction (may require staged procedure)
- Transfer or grafting
10. Prognosis & Outcomes
Natural History
Without treatment, Smith's fractures would heal with malunion in volar angulation. This malunion affects:
- Wrist biomechanics (altered load transfer)
- Grip strength (reduced by 20-40%)
- Forearm rotation (limited pronation/supination)
- Pain (chronic, activity-related)
- Appearance (visible deformity)
Outcomes with Treatment
Volar Locking Plate ORIF [4,6,17]
| Outcome Measure | Result |
|---|---|
| Union rate | 98-100% |
| Functional outcome (DASH) | Good to excellent in 85-95% |
| Grip strength | 80-95% of contralateral |
| Range of motion | 85-95% of contralateral |
| Complication rate | 10-15% (mostly minor) |
| Return to work | 6-12 weeks (office); 12-16 weeks (manual) |
| Patient satisfaction | > 90% satisfied |
Conservative Management [3]
| Outcome Measure | Result |
|---|---|
| Successful maintenance | 50-70% |
| Conversion to surgery | 30-50% |
| Functional outcome if maintained | Good if anatomic reduction maintained |
| Malunion rate | Higher than surgical |
Prognostic Factors
Favourable Factors
- Young age
- Extra-articular fracture (Type I)
- Anatomic reduction achieved
- Early mobilisation post-surgery
- Good bone quality
- Compliant with rehabilitation
- No associated ligamentous injury
Unfavourable Factors
- Intra-articular involvement (Type II)
- Significant comminution
- Associated DRUJ injury
- Osteoporotic bone
- Late presentation
- Delayed treatment
- Poor compliance
- CRPS development
- Workman's compensation claim [18]
Return to Activity
| Activity | Timeline |
|---|---|
| Driving | 4-8 weeks (when comfortable, able to perform emergency stop) |
| Office work | 2-4 weeks |
| Light manual work | 6-8 weeks |
| Heavy manual work | 12-16 weeks |
| Contact sports | 12-16 weeks |
| Full unrestricted activity | 3-6 months |
11. Evidence & Guidelines
Key Guidelines
BOAST 12: The Management of Distal Radius Fractures (BOA, 2017) [19]
Key recommendations:
- Operative fixation recommended for unstable fractures
- Volar locking plates preferred for volar displacement patterns
- Early mobilisation following stable internal fixation
- Assessment for osteoporosis in low-energy fractures in patients > 50 years
NICE NG38 and NG177: Fractures (Non-complex)
- Supports early mobilisation
- Appropriate surgical intervention for displaced/unstable fractures
- Falls prevention programmes for elderly
AAOS Clinical Practice Guideline: Distal Radius Fractures (2021)
- Moderate evidence supporting operative fixation for displaced, unstable fractures
- Volar locking plates demonstrate comparable outcomes to other fixation methods
Landmark Trials
DRAFFT Trial (Costa et al., 2014) [20]
| Aspect | Detail |
|---|---|
| Design | Multicentre RCT (UK) |
| Population | Adults with dorsally displaced DRF |
| Comparison | K-wire fixation vs volar locking plate |
| Primary outcome | PRWE at 12 months |
| Key finding | No significant difference at 12 months |
| Relevance to Smith's | Trial focused on dorsally displaced fractures; volar locking remains preferred for volarly displaced (Smith's) due to instability |
DRAFFT-2 Trial (Costa et al., 2022)
| Aspect | Detail |
|---|---|
| Design | Multicentre RCT (UK) |
| Population | Adults with DRF suitable for conservative or surgical management |
| Comparison | ORIF vs manipulation and cast |
| Key finding | Small difference favouring surgery at 12 months; diminishes over time |
| Relevance | Supports conservative management for stable dorsally displaced fractures, but Smith's remain unstable pattern requiring surgery |
Evidence Summary
| Intervention | Evidence Level | Key Evidence |
|---|---|---|
| Volar locking plate for displaced Smith's | 2a | Multiple cohort studies, systematic reviews showing excellent outcomes [4,6,17] |
| Conservative management | 2b | Case series demonstrating high failure rate (30-50%) [3] |
| Early mobilisation post-surgery | 1b | RCTs showing faster recovery, equivalent outcomes |
| CT for pre-operative planning | 2b | Improved characterisation of complex fractures [15] |
| Carpal tunnel release for acute CTS | 4 | Case series, standard of care [5] |
12. Examination-Focused Content
Common Exam Questions
FRCS Orth Viva Questions
- "Describe the classification of Smith's fractures and how this influences management."
- "What is the mechanism of injury in Smith's fracture and how does it differ from Colles' fracture?"
- "How would you manage a 55-year-old with a displaced Smith's fracture and median nerve symptoms?"
- "Describe your surgical approach for volar plating of a distal radius fracture."
- "What complications are specific to volar plate fixation?"
- "How do you position the volar plate and why is this important?"
Viva Points
Viva Point: Opening Statement
"Smith's fracture is a distal radius fracture characterised by volar displacement and angulation, representing the mechanical opposite of Colles' fracture. It was first described by Robert William Smith in Dublin in 1847 and accounts for 3-5% of distal radius fractures. The injury typically results from a fall onto a flexed wrist or direct dorsal blow and is classified using the Thomas classification into three types based on fracture pattern."
Key Facts to Mention
- Thomas classification: Type I (extra-articular transverse), Type II (intra-articular volar Barton), Type III (juxta-articular oblique)
- Inherently unstable due to volar displacement and deforming forces of wrist flexors
- Conservative management has 30-50% failure rate
- Volar locking plate is gold standard for displaced fractures
- Acute carpal tunnel syndrome in 5-15% — requires urgent decompression
- Watershed line concept important for plate positioning to avoid FPL rupture
Evidence to Quote
- DRAFFT trial: K-wire vs plate for dorsally displaced DRF
- BOA BOAST 12 guidelines
- High redisplacement rate with conservative management (30-50%)
Model Answer
Q: "A 45-year-old motorcyclist presents following a fall with wrist pain. X-ray shows a volarly displaced distal radius fracture. How would you manage this patient?"
A: "This sounds like a Smith's fracture, a distal radius fracture with volar displacement, likely sustained from handlebar impact.
My initial assessment would include a thorough history of the mechanism, assessment of handedness and occupation, and any relevant comorbidities.
On examination, I would look for the classic 'garden spade' deformity with volar prominence. I would perform a comprehensive neurovascular examination, specifically documenting median nerve function — motor power of APB and sensory testing of the radial three and a half digits — as acute carpal tunnel syndrome occurs in 5-15% of Smith's fractures. I would assess for open wounds and compartment syndrome.
I would request PA and lateral radiographs of the wrist. On the lateral view, I would expect to see volar angulation and displacement of the distal fragment. I would classify this according to the Thomas classification — Type I if extra-articular, Type II if there is volar lip involvement, or Type III if an oblique juxta-articular pattern.
If there is significant displacement, I would perform closed reduction with analgesia using traction, supination, wrist extension, and dorsal pressure on the distal fragment, then apply an above-elbow backslab. I would repeat the neurovascular examination and obtain post-reduction films.
Definitive management for a displaced Smith's fracture in this healthy working-age patient would be operative fixation with a volar locking plate through the modified Henry approach. This provides stable fixation, allows early mobilisation, and has excellent outcomes with 85-95% achieving good to excellent functional results.
Post-operatively, I would commence early finger range of motion exercises and begin wrist mobilisation at 2 weeks. I would counsel the patient regarding return to work at 6-12 weeks for office duties or 12-16 weeks for manual work.
If there were any median nerve symptoms, I would treat this as urgent and ensure carpal tunnel decompression was performed at the time of surgery through extension of the volar approach."
Common Mistakes in Exams
What Fails Candidates
- Confusing Smith's and Colles' fracture mechanisms and deformities
- Not mentioning median nerve assessment as a priority
- Recommending conservative management for a displaced Smith's fracture
- Not knowing the Thomas classification
- Failing to describe the reduction manoeuvre correctly (should be supination and extension, opposite to Colles')
- Not mentioning the watershed line when discussing volar plate positioning
- Not recognising that Smith's fractures are inherently unstable
13. Patient/Layperson Explanation
What is a Smith's Fracture?
A Smith's fracture is a break in the main bone of your forearm (the radius) near the wrist. Unlike the more common type of wrist fracture where the bone tilts backward, in a Smith's fracture the broken end tilts toward your palm. It's sometimes called a "reverse Colles' fracture."
How does it happen?
This type of break usually happens in one of two ways:
- Falling onto a bent wrist — if you fall and land with your wrist curled under
- A direct blow — such as hitting your wrist on motorcycle handlebars during an accident
Why is surgery usually needed?
The muscles in your forearm that bend your wrist are very strong. These muscles attach to the broken piece of bone and keep pulling it out of position. This makes it very difficult to keep the bone in place with just a cast. Studies show that casts fail to hold the bone in the right position in about one-third to one-half of cases.
Surgery involves putting a small metal plate and screws on the inside of your wrist bone to hold it in place while it heals. This is a very common and successful operation.
What are the risks?
The main concern with Smith's fracture is pressure on a nerve that runs through your wrist (the median nerve). If the broken bone presses on this nerve, you may feel numbness or tingling in your thumb, index, and middle fingers. If this happens, you need treatment quickly to release the pressure on the nerve.
What to expect after surgery
- Hospital stay: Usually same-day or overnight
- Wrist support: You may have a splint for the first week or two
- Finger exercises: Start immediately to prevent stiffness
- Wrist exercises: Begin at 2 weeks
- Suture removal: At 2 weeks
- Return to office work: 2-4 weeks
- Return to driving: 4-8 weeks (when comfortable)
- Return to manual work: 12-16 weeks
- Full recovery: 3-6 months
When to seek urgent help
Contact your doctor or go to A&E if you notice:
- Numbness or tingling in your thumb, index, or middle fingers
- Fingers becoming pale, cold, or blue
- Increasing pain despite painkillers
- Significant swelling not improving with elevation
- Wound problems — redness, discharge, or opening
14. References
Primary Sources
-
Nellans KW, Kowalski E, Chung KC. The epidemiology of distal radius fractures. Hand Clin. 2012;28(2):113-125. doi:10.1016/j.hcl.2012.02.001 PMID: 22554654
-
Fernandez DL. Distal radius fracture: the rationale of a classification. Chir Main. 2001;20(6):411-425. doi:10.1016/s1297-3203(01)00073-x PMID: 11778830
-
Handoll HH, Madhok R. Conservative interventions for treating distal radial fractures in adults. Cochrane Database Syst Rev. 2003;(2):CD000314. doi:10.1002/14651858.CD000314 PMID: 12804395
-
Orbay JL, Fernandez DL. Volar fixed-angle plate fixation for unstable distal radius fractures in the elderly patient. J Hand Surg Am. 2004;29(1):96-102. doi:10.1016/j.jhsa.2003.09.015 PMID: 14751111
-
Dyer G, Lozano-Calderon S, Gannon C, Baratz M, Ring D. Predictors of acute carpal tunnel syndrome associated with fracture of the distal radius. J Hand Surg Am. 2008;33(8):1309-1313. doi:10.1016/j.jhsa.2008.04.013 PMID: 18929193
-
Rozental TD, Blazar PE. Functional outcome and complications after volar plating for dorsally displaced, unstable fractures of the distal radius. J Hand Surg Am. 2006;31(3):359-365. doi:10.1016/j.jhsa.2005.10.010 PMID: 16516728
-
Court-Brown CM, Caesar B. Epidemiology of adult fractures: A review. Injury. 2006;37(8):691-697. doi:10.1016/j.injury.2006.04.130 PMID: 16814787
-
Brogren E, Petranek M, Atroshi I. Incidence and characteristics of distal radius fractures in a southern Swedish region. BMC Musculoskelet Disord. 2007;8:48. doi:10.1186/1471-2474-8-48 PMID: 17540030
-
Jerrhag D, Englund M, Karlsson MK, Rosengren BE. Epidemiology and time trends of distal forearm fractures in adults - a study of 11.2 million person-years in Sweden. BMC Musculoskelet Disord. 2017;18(1):240. doi:10.1186/s12891-017-1596-z PMID: 28578694
-
Oyen J, Brudvik C, Gjesdal CG, Tell GS, Lie SA, Hove LM. Osteoporosis as a risk factor for distal radial fractures: a case-control study. J Bone Joint Surg Am. 2011;93(4):348-356. doi:10.2106/JBJS.J.00303 PMID: 21239661
-
Ralis ZA. Epidemic of fractures during period of snow and ice. Br Med J (Clin Res Ed). 1981;282(6264):603-605. doi:10.1136/bmj.282.6264.603 PMID: 6781595
-
Orbay JL, Touhami A. Current concepts in volar fixed-angle fixation of unstable distal radius fractures. Clin Orthop Relat Res. 2006;445:58-67. doi:10.1097/01.blo.0000205891.96575.0f PMID: 16505728
-
Thomas FB. Reduction of Smith's fracture. J Bone Joint Surg Br. 1957;39-B(3):463-470. doi:10.1302/0301-620X.39B3.463 PMID: 13463033
-
Lafontaine M, Hardy D, Delince P. Stability assessment of distal radius fractures. Injury. 1989;20(4):208-210. doi:10.1016/0020-1383(89)90113-7 PMID: 2592094
-
Cole RJ, Bindra RR, Evanoff BA, Gilula LA, Yamaguchi K, Gelberman RH. Radiographic evaluation of osseous displacement following intra-articular fractures of the distal radius: reliability of plain radiography versus computed tomography. J Hand Surg Am. 1997;22(5):792-800. doi:10.1016/S0363-5023(97)80071-8 PMID: 9330135
-
Arora R, Lutz M, Hennerbichler A, Krappinger D, Espen D, Gabl M. Complications following internal fixation of unstable distal radius fracture with a palmar locking-plate. J Orthop Trauma. 2007;21(5):316-322. doi:10.1097/BOT.0b013e318059b993 PMID: 17485996
-
Jupiter JB, Marent-Huber M; LCP Study Group. Operative management of distal radial fractures with 2.4-millimeter locking plates: a multicenter prospective case series. J Bone Joint Surg Am. 2009;91(1):55-65. doi:10.2106/JBJS.G.01498 PMID: 19122079
-
Chung KC, Kotsis SV, Kim HM. Predictors of functional outcomes after surgical treatment of distal radius fractures. J Hand Surg Am. 2007;32(1):76-83. doi:10.1016/j.jhsa.2006.10.010 PMID: 17218179
-
British Orthopaedic Association. BOAST 12: The Management of Distal Radial Fractures. 2017. Available at: https://www.boa.ac.uk/standards-guidance/boast.html
-
Costa ML, Achten J, Parsons NR, et al. Percutaneous fixation with Kirschner wires versus volar locking plate fixation in adults with dorsally displaced fracture of distal radius: randomised controlled trial. BMJ. 2014;349:g4807. doi:10.1136/bmj.g4807 PMID: 25096595
15. Summary Box
| Aspect | Key Points |
|---|---|
| Definition | Distal radius fracture with volar displacement/angulation (reverse Colles') |
| Classification | Thomas: Type I (extra-articular), Type II (intra-articular), Type III (oblique) |
| Mechanism | Fall on flexed wrist OR direct dorsal blow |
| Clinical Finding | "Garden spade" deformity (volar prominence) |
| Radiograph | Lateral view shows volar angulation (opposite to Colles') |
| Key Complication | Acute carpal tunnel syndrome (5-15%) |
| Stability | Inherently unstable — high failure rate with conservative management (30-50%) |
| Treatment | Volar locking plate ORIF is gold standard for displaced fractures |
| Prognosis | Excellent with surgical fixation (85-95% good to excellent outcomes) |
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate guidelines and specialists for patient care.
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Learning map
Use these linked topics to study the concept in sequence and compare related presentations.
Prerequisites
Start here if you need the foundation before this topic.
- Distal Radius Anatomy
- Wrist Biomechanics
Differentials
Competing diagnoses and look-alikes to compare.
- Colles Fracture
- Barton Fracture
- Die-Punch Fracture
Consequences
Complications and downstream problems to keep in mind.
- Carpal Tunnel Syndrome
- DRUJ Instability